G2Cdb::Gene report

Gene id
Gene symbol
Homo sapiens
MAP/microtubule affinity-regulating kinase 2
G00000156 (Mus musculus)

Databases (7)

ENSG00000072518 (Ensembl human gene)
2011 (Entrez Gene)
506 (G2Cdb plasticity & disease)
MARK2 (GeneCards)
600526 (OMIM)
Marker Symbol
HGNC:3332 (HGNC)
Protein Sequence
Q7KZI7 (UniProt)

Synonyms (2)

  • PAR-1
  • Par1b

Literature (45)

Pubmed - other

  • The 8th and 9th tandem spectrin-like repeats of utrophin cooperatively form a functional unit to interact with polarity-regulating kinase PAR-1b.

    Yamashita K, Suzuki A, Satoh Y, Ide M, Amano Y, Masuda-Hirata M, Hayashi YK, Hamada K, Ogata K and Ohno S

    Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fuku-ura, Kanazawa-ku, Yokohama 236-0004, Japan.

    Utrophin is a widely expressed paralogue of dystrophin, the protein responsible for Duchenne muscular dystrophy. Utrophin is a large spectrin-like protein whose C-terminal domain mediates anchorage to a laminin receptor, dystroglycan (DG). The rod domain, composed of 22 spectrin-like repeats, connects the N-terminal actin-binding domain and the C-terminal DG binding domain, and thus mediates molecular linkage between intracellular F-actin and extracellular basement membrane. Previously, we demonstrated that a cell polarity-regulating kinase, PAR-1b, interacts with the utrophin-DG complex, and positively regulates the interaction between utrophin and DG. In this study, we demonstrate that the 8th and 9th spectrin-like repeats (R8 and R9) of utrophin cooperatively form a PAR-1b-interacting domain, and that Ser1258 within R9 is specifically phosphorylated by PAR-1b. Substitution of Ser1258 to alanine reduces the interaction between utrophin and DG, suggesting that the Ser1258 phosphorylation contributes to the stabilization of the utrophin-DG complex. Interestingly, PAR-1b also binds and phosphorylates R8-9 of dystrophin, and colocalizes with dystrophin at the skeletal muscle membrane. These results reveal a novel function of the rod domain of utrophin beyond that of a passive structural linker connecting the N- and C-terminal domain.

    Biochemical and biophysical research communications 2010;391;1;812-7

  • Defining the human deubiquitinating enzyme interaction landscape.

    Sowa ME, Bennett EJ, Gygi SP and Harper JW

    Department of Pathology, Harvard Medical School, Boston, MA 02115, USA.

    Deubiquitinating enzymes (Dubs) function to remove covalently attached ubiquitin from proteins, thereby controlling substrate activity and/or abundance. For most Dubs, their functions, targets, and regulation are poorly understood. To systematically investigate Dub function, we initiated a global proteomic analysis of Dubs and their associated protein complexes. This was accomplished through the development of a software platform called CompPASS, which uses unbiased metrics to assign confidence measurements to interactions from parallel nonreciprocal proteomic data sets. We identified 774 candidate interacting proteins associated with 75 Dubs. Using Gene Ontology, interactome topology classification, subcellular localization, and functional studies, we link Dubs to diverse processes, including protein turnover, transcription, RNA processing, DNA damage, and endoplasmic reticulum-associated degradation. This work provides the first glimpse into the Dub interaction landscape, places previously unstudied Dubs within putative biological pathways, and identifies previously unknown interactions and protein complexes involved in this increasingly important arm of the ubiquitin-proteasome pathway.

    Funded by: NIA NIH HHS: AG085011, R01 AG011085, R01 AG011085-16; NIGMS NIH HHS: GM054137, GM67945, R01 GM054137, R01 GM054137-14, R01 GM067945

    Cell 2009;138;2;389-403

  • The polarity protein Par1b/EMK/MARK2 regulates T cell receptor-induced microtubule-organizing center polarization.

    Lin J, Hou KK, Piwnica-Worms H and Shaw AS

    Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA.

    Engagement of a T cell to an APC induces the formation of an immunological synapse as well as reorientation of the microtubule-organizing center (MTOC) toward the APC. How signals emanating from the TCR induce MTOC polarization is not known. One group of proteins known to play a critical role in asymmetric cell division and cell polarization is the partitioning defective (Par) family of proteins. In this study we found that Par1b, a member of the Par family of proteins, was inducibly phosphorylated following TCR stimulation. This phosphorylation resulted in 14-3-3 protein binding and caused the relocalization of Par1b from the membrane into the cytoplasm. Because a dominant-negative form of Par1b blocked TCR-induced MTOC polarization, our data suggest that Par1b functions in the establishment of T cell polarity following engagement to an APC.

    Funded by: Howard Hughes Medical Institute: HHMI_SHAW_A; NIAID NIH HHS: R37 AI057966, R37 AI057966-05

    Journal of immunology (Baltimore, Md. : 1950) 2009;183;2;1215-21

  • High loading dose of clopidogrel is unable to satisfactorily inhibit platelet reactivity in patients with glycoprotein IIIA gene polymorphism: a genetic substudy of PRAGUE-8 trial.

    Motovska Z, Widimsky P, Kvasnicka J, Petr R, Bilkova D, Hajkova J, Marinov I, Simek S, Kala P and PRAGUE-8 study investigators

    Third Medical Faculty of Charles University, University Hospital Kralovske Vinohrady, Prague, Czech Republic. zuzana.motovska@iex.cz

    The study aimed to assess the impact of nine polymorphisms of genes encoding platelet receptors, enzymes, and hemostatic factors on clopidogrel efficacy to inhibit platelet reactivity in patients with stable coronary artery disease undergoing elective coronary angiography either with or without ad hoc percutaneous coronary intervention. The study was performed as a genetic substudy of the PRAGUE-8 trial. Ninety-five patients pretreated with 600 mg clopidogrel at least 6 h prior to coronary angiography were tested. Baseline platelet reactivity to ADP was assessed before the drug was administered. Clopidogrel efficacy was tested again at 12 and 28 h after administration. Polymorphisms of platelet receptors, glycoprotein (GP) Ia (807C/T), GPVI (13254C/T), GPIIIa (PlA1/PlA2), PAR-1 (IVSn-14A/T), P2Y12 (32C/T), P2Y12 (H1/H2) haplotype, gene variations of cyclooxygenase-1, Leiden, and factor II mutations were studied. Flow cytometric tests of vasodilator-stimulated phosphoprotein phosphorylation states were used as a measure of drug efficacy. None of the gene polymorphisms influenced baseline ADP-induced platelet reactivity significantly. Twenty-eight hours after drug administration, differences in suppression of ADP-induced platelet reactivity were observed between polymorphism-positive and polymorphism-negative patients. Inhibition of platelet reactivity, after 600 mg of clopidogrel, was significantly less in carriers of PlA2 (P=0.009) for mean decrease in platelet reactivity index. The proportion of clopidogrel nonresponders (platelet reactivity index >50%) was apparently higher in PlA2 carriers in comparison with PlA1/PlA1 patients (54 vs. 24%, P=0.082). A 600 mg loading dose of clopidogrel failed to acceptably inhibit platelet reactivity in patients who were positive for the PlA2 polymorphism.

    Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis 2009;20;4;257-62

  • Phosphorylation of the Par-1 polarity kinase by protein kinase D regulates 14-3-3 binding and membrane association.

    Watkins JL, Lewandowski KT, Meek SE, Storz P, Toker A and Piwnica-Worms H

    Department of Cell Biology and Physiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.

    The Par-1 protein kinases are conserved from yeast to humans, where they function as key polarity determinants. The mammalian Par-1 family is comprised of 4 members (Par-1a, -b, -c, and -d). Previously, we demonstrated that atypical protein kinase C (aPKC) phosphorylates the Par-1 kinases on a conserved threonine residue (T595) to regulate localization and kinase activity. Here, we demonstrate that Par-1b is also regulated by another arm of the PKC pathway, one that involves novel PKCs (nPKC) and protein kinase D. Treatment of cells with the PKC activator phorbol-12-myristate-13-acetate (PMA) potently stimulated phosphorylation of Par-1b on serine 400 (S400), a residue that is conserved in all 4 mammalian Par-1 kinases as well as the fly ortholog. We demonstrate that PMA stimulates nPKC to activate PKD, which in turn directly phosphorylates Par-1b on S400 to positively regulate 14-3-3 binding and to negatively regulate membrane association. Thus, 2 arms of the PKC pathway regulate interactions between Par-1b and 14-3-3 proteins: one involving aPKC and the other nPKC/PKD.

    Funded by: Howard Hughes Medical Institute; NCI NIH HHS: CA075134, R01 CA075134, T32 CA113275

    Proceedings of the National Academy of Sciences of the United States of America 2008;105;47;18378-83

  • Dishevelled-induced phosphorylation regulates membrane localization of Par1b.

    Terabayashi T, Funato Y and Miki H

    Laboratory of Intracellular Signaling, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.

    Par1b is an evolutionarily conserved kinase that plays crucial roles in cell polarity. Controlling intracellular localization of Par1b is important for its biological activity. We previously reported that Wnt stimulation or expression of Dvl promotes accumulation of Par1b in the membrane (T. Terabayashi, T.J. Itoh, H. Yamaguchi, Y. Yoshimura, Y. Funato, S. Ohno, H. Miki, Polarity-Regulating Kinase Partitioning-Defective 1/Microtubule Affinity-Regulating Kinase 2 Negatively Regulates Development of Dendrites on Hippocampal Neurons, J. Neurosci. 27 (2007) 13098-13107). However, its molecular mechanism remains unclear. Here we show the importance of Par1b phosphorylation in the regulation of membrane localization. We find that Thr-324 is phosphorylated in a Dvl-dependent manner. Interestingly, the conversion of Thr-324 to Glu results in a significant accumulation of Par1b in the membrane, without any effects on the kinase activity. Moreover, the phospho-mimicking Par1b mutant does not antagonistically function against Dvl in microtubule stabilization and neurite extension, although wildtype Par1b does. These results suggest that membrane accumulation of Par1b induced by Dvl is regulated by its phosphorylation status, which is important for Par1b to regulate the microtubule dynamics.

    Biochemical and biophysical research communications 2008;375;4;660-5

  • Akt and CHIP coregulate tau degradation through coordinated interactions.

    Dickey CA, Koren J, Zhang YJ, Xu YF, Jinwal UK, Birnbaum MJ, Monks B, Sun M, Cheng JQ, Patterson C, Bailey RM, Dunmore J, Soresh S, Leon C, Morgan D and Petrucelli L

    Department of Molecular Pharmacology and Physiology and H. Lee Moffitt Cancer Center, University of South Florida, Tampa, FL 33612, USA. cdickey1@health.usf.edu

    A hallmark of the pathology of Alzheimer's disease is the accumulation of the microtubule-associated protein tau into fibrillar aggregates. Recent studies suggest that they accumulate because cytosolic chaperones fail to clear abnormally phosphorylated tau, preserving a pool of toxic tau intermediates within the neuron. We describe a mechanism for tau clearance involving a major cellular kinase, Akt. During stress, Akt is ubiquitinated and degraded by the tau ubiquitin ligase CHIP, and this largely depends on the Hsp90 complex. Akt also prevents CHIP-induced tau ubiquitination and its subsequent degradation, either by regulating the Hsp90/CHIP complex directly or by competing as a client protein with tau for binding. Akt levels tightly regulate the expression of CHIP, such that, as Akt levels are suppressed, CHIP levels also decrease, suggesting a potential stress response feedback mechanism between ligase and kinase activity. We also show that Akt and the microtubule affinity-regulating kinase 2 (PAR1/MARK2), a known tau kinase, interact directly. Akt enhances the activity of PAR1 to promote tau hyperphosphorylation at S262/S356, a tau species that is not recognized by the CHIP/Hsp90 complex. Moreover, Akt1 knockout mice have reduced levels of tau phosphorylated at PAR1/MARK2 consensus sites. Hence, Akt serves as a major regulator of tau biology by manipulating both tau kinases and protein quality control, providing a link to several common pathways that have demonstrated dysfunction in Alzheimer's disease.

    Funded by: NIA NIH HHS: K99 AG031291, K99 AG031291-01, K99-AG31291, P01 AG017216, R00 AG031291, R00 AG031291-02, R00 AG031291-02S1, R01-AG17216-08; NIDDK NIH HHS: R01 DK056886, R01-DK56886

    Proceedings of the National Academy of Sciences of the United States of America 2008;105;9;3622-7

  • Analysis of detergent-resistant membranes of Helicobacter pylori infected gastric adenocarcinoma cells reveals a role for MARK2/Par1b in CagA-mediated disruption of cellular polarity.

    Zeaiter Z, Cohen D, Müsch A, Bagnoli F, Covacci A and Stein M

    Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7.

    Detergent-resistant membranes of eukaryotic cells are enriched in many important cellular signalling molecules and frequently targeted by bacterial pathogens. To learn more about pathogenic mechanisms of Helicobacter pylori and to elucidate novel effects on host epithelial cells, we investigated how bacterial co-cultivation changes the protein composition of detergent-resistant membranes of gastric adenocarcinoma (AGS) tissue culture cells. Using iTRAQ (isobaric tags for relative and absolute quantification) analysis we identified several cellular proteins, which are potentially related to H. pylori virulence. One of the proteins, which showed a significant infection-dependent increase in detergent resistance, was the polarity-associated serine/threonine kinase MARK2 (EMK1/Par-1b). We demonstrate that H. pylori causes the recruitment of MARK2 from the cytosol to the plasma membrane, where it colocalizes with the bacteria and interacts with CagA. Using Mardin Darby Canine Kidney (MDCK) monolayers and a three-dimensional MDCK tissue culture model we showed that association of CagA with MARK2 not only causes disruption of apical junctions, but also inhibition of tubulogenesis and cell differentiation.

    Cellular microbiology 2008;10;3;781-94

  • Prognosis in human melanoma: PAR-1 expression is superior to other coagulation components and VEGF.

    Depasquale I and Thompson WD

    Department of Plastic Surgery, Aberdeen Royal Infirmary, Aberdeen, UK.

    Aims: Two hundred and four accessible cases of malignant melanoma from the Grampian region of Scotland, collected over a period of 4 years, with minimum follow-up of 2 years, were studied for coagulation factors and vascular endothelial growth factor (VEGF) expression as potential prognostic markers. The aim was to allow comparison with previous work using microvessel density on the same cases.

    Immunohistochemistry for VEGF, tissue factor (TF), fibrin and protease-activated thrombin receptor (PAR)-1 in 204 cases of melanoma was performed, and intensity of expression scored. Chalkley microvessel counts (MVD) were obtained for the tumour edge. TF expression and presence of fibrin correlated well with Breslow thickness and ulceration, reaching statistical significance, but surprisingly not for metastatic recurrence. Fibrin was variably present in over half the cases, located at the invasive edge, ulcerated surface and between tumour cell surfaces. In a few cases fibrin was within tumour cells, typically co-located with melanin and confirmed by electron microscopy. In contrast, immunohistochemistry for PAR-1 produced statistically significant results, correlating expression with Breslow thickness (P < or = 0.001), ulceration (P = 0.001) and recurrence (P < or = 0.005). Intensity of reactivity of VEGF correlated significantly with Breslow thickness, Clark level, ulceration and MVD, but not for metastatic recurrence.

    Conclusions: It appears paradoxical that VEGF expression is not more predictive of recurrence, but even low expression may be sufficient for tumour angiogenesis and other factors must govern tumour aggression. Antagonism of VEGF may still prove a successful adjunct in future therapeutic trials. Both MVD and PAR-1 can be used as adjuncts to Breslow thickness and ulceration as prognostic indicators for melanoma, as they appear to give independent information for all thicknesses. PAR-1 expression is the best antibody marker of recurrence risk from those studied. It remains to be seen whether this methodology can predict response to novel antiangiogenic therapies currently entering trial.

    Histopathology 2008;52;4;500-9

  • Polarity-regulating kinase partitioning-defective 1/microtubule affinity-regulating kinase 2 negatively regulates development of dendrites on hippocampal neurons.

    Terabayashi T, Itoh TJ, Yamaguchi H, Yoshimura Y, Funato Y, Ohno S and Miki H

    Laboratory of Intracellular Signaling, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.

    Neurons are highly polarized cells that possess two morphologically and functionally different types of protrusions, axons and dendrites, that function in the transmission and reception of neural signals, respectively. A great deal of attention has been paid to the specification and guidance of axons, but the mechanism of dendrite development remains mostly unknown. We report here that a polarity-regulating kinase, partitioning-defective 1 (Par1b)/microtubule affinity-regulating kinase 2 (MARK2), specifically regulates development of dendrites in hippocampal neurons. Ectopic expression of Par1b/MARK2 shortens the length and decreases branching of dendrites without significant effects on axons. Knockdown of endogenous Par1b/MARK2 by RNA interference stimulates dendrite development. Wnt stimulation and Dishevelled expression, both of which are known to induce dendrite development, induced recruitment of Par1b/MARK2 to the membrane fraction. Expression of a Par1b/MARK2 mutant, that contains a myristoylation signal and accumulates exclusively in membranes, does not affect dendrite development. In addition, Par1b/MARK2 efficiently phosphorylated MAP2, which is localized mainly in dendrites. These results indicate that Par1b/MARK2 negatively regulates dendrite development through phosphorylation of MAP2.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2007;27;48;13098-107

  • Proteomics analysis of protein kinases by target class-selective prefractionation and tandem mass spectrometry.

    Wissing J, Jänsch L, Nimtz M, Dieterich G, Hornberger R, Kéri G, Wehland J and Daub H

    Department of Cell Biology, Helmholtz Centre for Infection Research (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany.

    Protein kinases constitute a large superfamily of enzymes with key regulatory functions in nearly all signal transmission processes of eukaryotic cells. However, due to their relatively low abundance compared with the vast majority of cellular proteins, currently available proteomics techniques do not permit the comprehensive biochemical characterization of protein kinases. To address these limitations, we have developed a prefractionation strategy that uses a combination of immobilized low molecular weight inhibitors for the selective affinity capture of protein kinases. This approach resulted in the direct purification of cell type-specific sets of expressed protein kinases, and more than 140 different members of this enzyme family could be detected by LC-MS/MS. Furthermore the enrichment technique combined with phosphopeptide fractionation led to the identification of more than 200 different phosphorylation sites on protein kinases, which often remain occluded in global phosphoproteome analysis. As the phosphorylation states of protein kinases can provide a readout for the signaling activities within a cellular system, kinase-selective phosphoproteomics based on the procedures described here has the potential to become an important tool in signal transduction analysis.

    Molecular & cellular proteomics : MCP 2007;6;3;537-47

  • Activation of PAR-1 kinase and stimulation of tau phosphorylation by diverse signals require the tumor suppressor protein LKB1.

    Wang JW, Imai Y and Lu B

    Department of Pathology, Stanford University School of Medicine, and Geriatric Research, Education, and Clinical Center/Veterans Affairs Palo Alto Health Care System, Palo Alto, California 94304, USA.

    Aberrant phosphorylation of tau is associated with a number of neurodegenerative diseases, including Alzheimer's disease (AD). The molecular mechanisms by which tau phosphorylation is regulated under normal and disease conditions are not well understood. Microtubule affinity regulating kinase (MARK) and PAR-1 have been identified as physiological tau kinases, and aberrant phosphorylation of MARK/PAR-1 target sites in tau has been observed in AD patients and animal models. Here we show that phosphorylation of PAR-1 by the tumor suppressor protein LKB1 is required for PAR-1 activation, which in turn promotes tau phosphorylation in Drosophila. Diverse stress stimuli, such as high osmolarity and overexpression of the human beta-amyloid precursor protein, can promote PAR-1 activation and tau phosphorylation in an LKB1-dependent manner. These results reveal a new function for the tumor suppressor protein LKB1 in a signaling cascade through which the phosphorylation and function of tau is regulated by diverse signals under physiological and pathological conditions.

    Funded by: NINDS NIH HHS: NS043167

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2007;27;3;574-81

  • Large-scale mapping of human protein-protein interactions by mass spectrometry.

    Ewing RM, Chu P, Elisma F, Li H, Taylor P, Climie S, McBroom-Cerajewski L, Robinson MD, O'Connor L, Li M, Taylor R, Dharsee M, Ho Y, Heilbut A, Moore L, Zhang S, Ornatsky O, Bukhman YV, Ethier M, Sheng Y, Vasilescu J, Abu-Farha M, Lambert JP, Duewel HS, Stewart II, Kuehl B, Hogue K, Colwill K, Gladwish K, Muskat B, Kinach R, Adams SL, Moran MF, Morin GB, Topaloglou T and Figeys D

    Protana, Toronto, Ontario, Canada.

    Mapping protein-protein interactions is an invaluable tool for understanding protein function. Here, we report the first large-scale study of protein-protein interactions in human cells using a mass spectrometry-based approach. The study maps protein interactions for 338 bait proteins that were selected based on known or suspected disease and functional associations. Large-scale immunoprecipitation of Flag-tagged versions of these proteins followed by LC-ESI-MS/MS analysis resulted in the identification of 24,540 potential protein interactions. False positives and redundant hits were filtered out using empirical criteria and a calculated interaction confidence score, producing a data set of 6463 interactions between 2235 distinct proteins. This data set was further cross-validated using previously published and predicted human protein interactions. In-depth mining of the data set shows that it represents a valuable source of novel protein-protein interactions with relevance to human diseases. In addition, via our preliminary analysis, we report many novel protein interactions and pathway associations.

    Molecular systems biology 2007;3;89

  • Global, in vivo, and site-specific phosphorylation dynamics in signaling networks.

    Olsen JV, Blagoev B, Gnad F, Macek B, Kumar C, Mortensen P and Mann M

    Center for Experimental BioInformatics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense, Denmark.

    Cell signaling mechanisms often transmit information via posttranslational protein modifications, most importantly reversible protein phosphorylation. Here we develop and apply a general mass spectrometric technology for identification and quantitation of phosphorylation sites as a function of stimulus, time, and subcellular location. We have detected 6,600 phosphorylation sites on 2,244 proteins and have determined their temporal dynamics after stimulating HeLa cells with epidermal growth factor (EGF) and recorded them in the Phosida database. Fourteen percent of phosphorylation sites are modulated at least 2-fold by EGF, and these were classified by their temporal profiles. Surprisingly, a majority of proteins contain multiple phosphorylation sites showing different kinetics, suggesting that they serve as platforms for integrating signals. In addition to protein kinase cascades, the targets of reversible phosphorylation include ubiquitin ligases, guanine nucleotide exchange factors, and at least 46 different transcriptional regulators. The dynamic phosphoproteome provides a missing link in a global, integrative view of cellular regulation.

    Cell 2006;127;3;635-48

  • A probability-based approach for high-throughput protein phosphorylation analysis and site localization.

    Beausoleil SA, Villén J, Gerber SA, Rush J and Gygi SP

    Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, Massachusetts 02115, USA.

    Data analysis and interpretation remain major logistical challenges when attempting to identify large numbers of protein phosphorylation sites by nanoscale reverse-phase liquid chromatography/tandem mass spectrometry (LC-MS/MS) (Supplementary Figure 1 online). In this report we address challenges that are often only addressable by laborious manual validation, including data set error, data set sensitivity and phosphorylation site localization. We provide a large-scale phosphorylation data set with a measured error rate as determined by the target-decoy approach, we demonstrate an approach to maximize data set sensitivity by efficiently distracting incorrect peptide spectral matches (PSMs), and we present a probability-based score, the Ascore, that measures the probability of correct phosphorylation site localization based on the presence and intensity of site-determining ions in MS/MS spectra. We applied our methods in a fully automated fashion to nocodazole-arrested HeLa cell lysate where we identified 1,761 nonredundant phosphorylation sites from 491 proteins with a peptide false-positive rate of 1.3%.

    Funded by: NHGRI NIH HHS: HG03456; NIGMS NIH HHS: GM67945

    Nature biotechnology 2006;24;10;1285-92

  • New role for hPar-1 kinases EMK and C-TAK1 in regulating localization and activity of class IIa histone deacetylases.

    Dequiedt F, Martin M, Von Blume J, Vertommen D, Lecomte E, Mari N, Heinen MF, Bachmann M, Twizere JC, Huang MC, Rider MH, Piwnica-Worms H, Seufferlein T and Kettmann R

    Cellular and Molecular Biology Unit, Faculty of Agronomy, B-5030, Gembloux, Belgium. dequiedt.f@fsagx.ac.be

    Class IIa histone deacetylases (HDACs) are found both in the cytoplasm and in the nucleus where they repress genes involved in several major developmental programs. In response to specific signals, the repressive activity of class IIa HDACs is neutralized through their phosphorylation on multiple N-terminal serine residues and 14-3-3-mediated nuclear exclusion. Here, we demonstrate that class IIa HDACs are subjected to signal-independent nuclear export that relies on their constitutive phosphorylation. We identify EMK and C-TAK1, two members of the microtubule affinity-regulating kinase (MARK)/Par-1 family, as regulators of this process. We further show that EMK and C-TAK1 phosphorylate class IIa HDACs on one of their multiple 14-3-3 binding sites and alter their subcellular localization and repressive function. Using HDAC7 as a paradigm, we extend these findings by demonstrating that signal-independent phosphorylation of the most N-terminal serine residue by the MARK/Par-1 kinases, i.e., Ser155, is a prerequisite for the phosphorylation of the nearby 14-3-3 site, Ser181. We propose that this multisite hierarchical phosphorylation by a variety of kinases allows for sophisticated regulation of class IIa HDACs function.

    Molecular and cellular biology 2006;26;19;7086-102

  • Structural variations in the catalytic and ubiquitin-associated domains of microtubule-associated protein/microtubule affinity regulating kinase (MARK) 1 and MARK2.

    Marx A, Nugoor C, Müller J, Panneerselvam S, Timm T, Bilang M, Mylonas E, Svergun DI, Mandelkow EM and Mandelkow E

    Max-Planck-Unit for Structural Molecular Biology, Notkestrasse 85, 22607 Hamburg, Germany.

    The microtubule-associated protein (MAP)/microtubule affinity regulating kinase (MARK)/Par-1 phosphorylates microtubule-associated proteins tau, MAP2, and MAP4 and is involved in the regulation of microtubule-based transport. Par-1, a homologue of MARK in Drosophila and Caenorhabditis elegans, is essential for the development of embryonic polarity. Four isoforms of MARK are found in humans. Recently, we reported the crystal structure of the catalytic and ubiquitin-associated domains of MARK2, an isoform enriched in brain (Panneerselvam, S., Marx, A., Mandelkow, E.-M., and Mandelkow, E. (2006) Structure 14, 173-183). It showed that the ubiquitin-associated domain (UBA) domain has an unusual fold and binds to the N-terminal lobe of the catalytic domain. This is at variance with a previous low resolution structure derived from small angle solution scattering (Jaleel, M., Villa, F., Deak, M., Toth, R., Prescott, A. R., Van Aalten, D. M., and Alessi, D. R. (2006) Biochem. J. 394, 545-555), which predicts binding of the UBA domain to the larger, C-terminal lobe. Here we report the crystal structure of the catalytic and UBA domain of another isoform, MARK1. Although the crystal packing of the two isoforms are unrelated, the overall conformations of the molecules are similar. Notably, the UBA domain has the same unusual conformation as in MARK2, and it binds at the same site. Remarkable differences occur in the catalytic domain at helix C, the catalytic loop, and the activation segment.

    The Journal of biological chemistry 2006;281;37;27586-99

  • PAR1b promotes cell-cell adhesion and inhibits dishevelled-mediated transformation of Madin-Darby canine kidney cells.

    Elbert M, Cohen D and Müsch A

    Margaret M. Dyson Vision Research Institute and Graduate Program in Pharmacology, Cornell University Medical College, New York, NY 10021, USA.

    Mammalian Par1 is a family of serine/threonine kinases comprised of four homologous isoforms that have been associated with tumor suppression and differentiation of epithelial and neuronal cells, yet little is known about their cellular functions. In polarizing kidney epithelial (Madin-Darby canine kidney [MDCK]) cells, the Par1 isoform Par1b/MARK2/EMK1 promotes the E-cadherin-dependent compaction, columnarization, and cytoskeletal organization characteristic of differentiated columnar epithelia. Here, we identify two functions of Par1b that likely contribute to its role as a tumor suppressor in epithelial cells. 1) The kinase promotes cell-cell adhesion and resistance of E-cadherin to extraction by nonionic detergents, a measure for the association of the E-cadherin cytoplasmic domain with the actin cytoskeleton, which is critical for E-cadherin function. 2) Par1b attenuates the effect of Dishevelled (Dvl) expression, an inducer of wnt signaling that causes transformation of epithelial cells. Although Dvl is a known Par1 substrate in vitro, we determined, after mapping the PAR1b-phosphorylation sites in Dvl, that PAR1b did not antagonize Dvl signaling by phosphorylating the wnt-signaling molecule. Instead, our data suggest that both proteins function antagonistically to regulate the assembly of functional E-cadherin-dependent adhesion complexes.

    Funded by: NEI NIH HHS: EY07138, T32 EY007138; NIDDK NIH HHS: R01 DK064842; NIGMS NIH HHS: GM-34107, R01 GM034107

    Molecular biology of the cell 2006;17;8;3345-55

  • AROS-29 is involved in adaptive response to oxidative stress.

    Montesano Gesualdi N, Chirico G, Catanese MT, Pirozzi G and Esposito F

    Università di Napoli Federico II, Dipartimento di Biochimica e Biotecnologie Mediche, Naples, Italy.

    Transient adaptation to mild oxidative stress was induced in human osteosarcoma cells chronically grown in sub-toxic concentrations of diethylmaleate (DEM), a glutathione (GSH) depleting agent. The adapted cells, compared to untreated cells, contain increased concentrations of GSH (4-6 fold) which, upon DEM withdrawal from the culture medium, return to normal values and are more resistant to subsequent oxidizing stress induced either by toxic concentrations of the same agent or by (H(2)O(2)) treatment. To investigate the molecular mechanisms involved in the adaptive response to oxidative stress, we analyzed the gene expression profiles of DEM-adapted cells by differential display. The expression of adaptive response to oxidative stress (AROS)-29 gene, coding for a transmembrane protein of unknown function, as well as of some known genes involved in energy metabolism, protein folding and membrane traffic is up-regulated in adapted cells. The increased resistance to both DNA damage and apoptosis, in cells stably overexpressing AROS-29, demonstrated its functional role in the protection against oxidative stress.

    Free radical research 2006;40;5;467-76

  • Human chromosome 11 DNA sequence and analysis including novel gene identification.

    Taylor TD, Noguchi H, Totoki Y, Toyoda A, Kuroki Y, Dewar K, Lloyd C, Itoh T, Takeda T, Kim DW, She X, Barlow KF, Bloom T, Bruford E, Chang JL, Cuomo CA, Eichler E, FitzGerald MG, Jaffe DB, LaButti K, Nicol R, Park HS, Seaman C, Sougnez C, Yang X, Zimmer AR, Zody MC, Birren BW, Nusbaum C, Fujiyama A, Hattori M, Rogers J, Lander ES and Sakaki Y

    RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. taylor@gsc.riken.jp

    Chromosome 11, although average in size, is one of the most gene- and disease-rich chromosomes in the human genome. Initial gene annotation indicates an average gene density of 11.6 genes per megabase, including 1,524 protein-coding genes, some of which were identified using novel methods, and 765 pseudogenes. One-quarter of the protein-coding genes shows overlap with other genes. Of the 856 olfactory receptor genes in the human genome, more than 40% are located in 28 single- and multi-gene clusters along this chromosome. Out of the 171 disorders currently attributed to the chromosome, 86 remain for which the underlying molecular basis is not yet known, including several mendelian traits, cancer and susceptibility loci. The high-quality data presented here--nearly 134.5 million base pairs representing 99.8% coverage of the euchromatic sequence--provide scientists with a solid foundation for understanding the genetic basis of these disorders and other biological phenomena.

    Funded by: Medical Research Council: G0000107; Wellcome Trust

    Nature 2006;440;7083;497-500

  • Structure of the catalytic and ubiquitin-associated domains of the protein kinase MARK/Par-1.

    Panneerselvam S, Marx A, Mandelkow EM and Mandelkow E

    Max Planck Unit for Structural Molecular Biology, Notkestrasse 85, 22607 Hamburg, Germany.

    The Ser/Thr kinase MARK2 phosphorylates tau protein at sites that cause detachment from microtubules in Alzheimer neurofibrillary degeneration. Homologs of MARK2 include Par-1 in C. elegans and Drosophila, which generates embryonic polarity. We report the X-ray structure of the catalytic and ubiquitin-associated domains (UBA) of human MARK2. The activity was altered by mutations in the ATP binding site and/or activation loop. The catalytic domain shows the small and large lobes typical of kinases. The substrate cleft is in an inactive, open conformation in the inactivated and the wild-type structure. The UBA domain is attached via a taut linker to the large lobe of the kinase domain and leans against a hydrophobic patch on the small lobe. The UBA structure is unusual because the orientation of its third helix is inverted, relative to previous structures. Possible implications of the structure for the regulation of kinase activity are discussed.

    Structure (London, England : 1993) 2006;14;2;173-83

  • Diversification of transcriptional modulation: large-scale identification and characterization of putative alternative promoters of human genes.

    Kimura K, Wakamatsu A, Suzuki Y, Ota T, Nishikawa T, Yamashita R, Yamamoto J, Sekine M, Tsuritani K, Wakaguri H, Ishii S, Sugiyama T, Saito K, Isono Y, Irie R, Kushida N, Yoneyama T, Otsuka R, Kanda K, Yokoi T, Kondo H, Wagatsuma M, Murakawa K, Ishida S, Ishibashi T, Takahashi-Fujii A, Tanase T, Nagai K, Kikuchi H, Nakai K, Isogai T and Sugano S

    Life Science Research Laboratory, Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo, 185-8601, Japan.

    By analyzing 1,780,295 5'-end sequences of human full-length cDNAs derived from 164 kinds of oligo-cap cDNA libraries, we identified 269,774 independent positions of transcriptional start sites (TSSs) for 14,628 human RefSeq genes. These TSSs were clustered into 30,964 clusters that were separated from each other by more than 500 bp and thus are very likely to constitute mutually distinct alternative promoters. To our surprise, at least 7674 (52%) human RefSeq genes were subject to regulation by putative alternative promoters (PAPs). On average, there were 3.1 PAPs per gene, with the composition of one CpG-island-containing promoter per 2.6 CpG-less promoters. In 17% of the PAP-containing loci, tissue-specific use of the PAPs was observed. The richest tissue sources of the tissue-specific PAPs were testis and brain. It was also intriguing that the PAP-containing promoters were enriched in the genes encoding signal transduction-related proteins and were rarer in the genes encoding extracellular proteins, possibly reflecting the varied functional requirement for and the restricted expression of those categories of genes, respectively. The patterns of the first exons were highly diverse as well. On average, there were 7.7 different splicing types of first exons per locus partly produced by the PAPs, suggesting that a wide variety of transcripts can be achieved by this mechanism. Our findings suggest that use of alternate promoters and consequent alternative use of first exons should play a pivotal role in generating the complexity required for the highly elaborated molecular systems in humans.

    Genome research 2006;16;1;55-65

  • GSK-3beta directly phosphorylates and activates MARK2/PAR-1.

    Kosuga S, Tashiro E, Kajioka T, Ueki M, Shimizu Y and Imoto M

    Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.

    In Alzheimer disease (AD), the microtubule-associated protein tau is found hyperphosphorylated in paired helical filaments. Among many phosphorylated sites in tau, Ser-262 is the major site for abnormal phosphorylation of tau in AD brain. The kinase known to phosphorylate this particular site is MARK2, whose activation mechanism is yet to be studied. Our first finding that treatment of cells with LiCl, a selective inhibitor of another major tau kinase, glycogen synthase kinase-3beta (GSK-3beta), inhibits phosphorylation of Ser-262 of tau led us to investigate the possible involvement of GSK-3beta in MARK2 activation. In vitro kinase reaction revealed that recombinant GSK-3beta indeed phosphorylates MARK2, whereas it failed to phosphorylate Ser-262 of tau. Our further findings led us to conclude that GSK-3beta phosphorylates MARK2 on Ser-212, one of the two reported phosphorylation sites (Thr-208 and Ser-212) found in the activation loop of MARK2. Down-regulation of either GSK-3beta or MARK2 by small interfering RNAs suppressed the level of phosphorylation on Ser-262. These results, respectively, indicated that GSK-3beta is responsible for phosphorylating Ser-262 of tau through phosphorylation and activation of MARK2 and that the phosphorylation of tau at this particular site is predominantly mediated by a GSK-3beta-MARK2 pathway. These findings are of interest in the context of the pathogenesis of AD.

    The Journal of biological chemistry 2005;280;52;42715-22

  • Targeted proteomic analysis of 14-3-3 sigma, a p53 effector commonly silenced in cancer.

    Benzinger A, Muster N, Koch HB, Yates JR and Hermeking H

    Molecular Oncology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried/Munich, Germany.

    To comprehensively identify proteins interacting with 14-3-3 sigma in vivo, tandem affinity purification and the multidimensional protein identification technology were combined to characterize 117 proteins associated with 14-3-3 sigma in human cells. The majority of identified proteins contained one or several phosphorylatable 14-3-3-binding sites indicating a potential direct interaction with 14-3-3 sigma. 25 proteins were not previously assigned to any function and were named SIP2-26 (for 14-3-3 sigma-interacting protein). Among the 92 interactors with known function were a number of proteins previously implicated in oncogenic signaling (APC, A-RAF, B-RAF, and c-RAF) and cell cycle regulation (AJUBA, c-TAK, PTOV-1, and WEE1). The largest functional classes comprised proteins involved in the regulation of cytoskeletal dynamics, polarity, adhesion, mitogenic signaling, and motility. Accordingly ectopic 14-3-3 sigma expression prevented cellular migration in a wounding assay and enhanced mitogen-activated protein kinase signaling. The functional diversity of the identified proteins indicates that induction of 14-3-3 sigma could allow p53 to affect numerous processes in addition to the previously characterized inhibitory effect on G2/M progression. The data suggest that the cancer-specific loss of 14-3-3 sigma expression by epigenetic silencing or p53 mutations contributes to cancer formation by multiple routes.

    Funded by: NCRR NIH HHS: RR11823-08

    Molecular & cellular proteomics : MCP 2005;4;6;785-95

  • Up-regulation of Flotillin-2 is associated with melanoma progression and modulates expression of the thrombin receptor protease activated receptor 1.

    Hazarika P, McCarty MF, Prieto VG, George S, Babu D, Koul D, Bar-Eli M and Duvic M

    Department of Dermatology, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA.

    Flotillin 2 (flot-2) is a highly conserved protein isolated from caveolae/lipid raft domains that tether growth factor receptors linked to signal transduction pathways. Flot-2 protein and mRNA were increased in tumorigenic and metastatic melanoma cell lines in vitro, and the immunostaining intensity increased substantially across a tissue array of melanocytic lesions. Flot-2 transfection transformed SB2 melanoma cells from nontumorigenic, nonmetastatic to highly tumorigenic and metastatic in a nude mouse xenograft model. SB2 cells stably transfected with the flot-2 cDNA (SB2-flot)-2 cells proliferated faster in the absence of serum, and their migration through Matrigel was additionally enhanced by thrombin. When SB2-flot-2 cells were compared with SB2-vector-control cells on a cancer gene pathway array, SB2-flot-2 cells had increased expression of protease activated receptor 1 (PAR-1) mRNA, a transmembrane, G-protein-coupled receptor involved in melanoma progression. PAR-1 and flot-2 were coimmunoprecipitated from SB2-flot-2 cells. Up-regulation of PAR-1 was additionally confirmed in SB2-flot-2 cells and melanoma cell lines. SB2-flot-2 cells transfected with flot-2-specific small-interfering RNAs made substantially less flot-2 and PAR-1 mRNA. In conclusion, flot-2 overexpression is associated with melanoma progression, with increased PAR-1 expression, and with transformation of SB2 melanoma cells to a highly metastatic line. Flot-2 binds to PAR-1, a known upstream mediator of major signal transduction pathways implicated in cell growth and metastasis, and may thereby influence tumor progression.

    Funded by: NCI NIH HHS: CA-16672, CA086814-K24

    Cancer research 2004;64;20;7361-9

  • The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).

    Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, Ko MS, Kawakami K, Suzuki Y, Sugano S, Gruber CE, Smith MR, Simmons B, Moore T, Waterman R, Johnson SL, Ruan Y, Wei CL, Mathavan S, Gunaratne PH, Wu J, Garcia AM, Hulyk SW, Fuh E, Yuan Y, Sneed A, Kowis C, Hodgson A, Muzny DM, McPherson J, Gibbs RA, Fahey J, Helton E, Ketteman M, Madan A, Rodrigues S, Sanchez A, Whiting M, Madari A, Young AC, Wetherby KD, Granite SJ, Kwong PN, Brinkley CP, Pearson RL, Bouffard GG, Blakesly RW, Green ED, Dickson MC, Rodriguez AC, Grimwood J, Schmutz J, Myers RM, Butterfield YS, Griffith M, Griffith OL, Krzywinski MI, Liao N, Morin R, Morrin R, Palmquist D, Petrescu AS, Skalska U, Smailus DE, Stott JM, Schnerch A, Schein JE, Jones SJ, Holt RA, Baross A, Marra MA, Clifton S, Makowski KA, Bosak S, Malek J and MGC Project Team

    The National Institutes of Health's Mammalian Gene Collection (MGC) project was designed to generate and sequence a publicly accessible cDNA resource containing a complete open reading frame (ORF) for every human and mouse gene. The project initially used a random strategy to select clones from a large number of cDNA libraries from diverse tissues. Candidate clones were chosen based on 5'-EST sequences, and then fully sequenced to high accuracy and analyzed by algorithms developed for this project. Currently, more than 11,000 human and 10,000 mouse genes are represented in MGC by at least one clone with a full ORF. The random selection approach is now reaching a saturation point, and a transition to protocols targeted at the missing transcripts is now required to complete the mouse and human collections. Comparison of the sequence of the MGC clones to reference genome sequences reveals that most cDNA clones are of very high sequence quality, although it is likely that some cDNAs may carry missense variants as a consequence of experimental artifact, such as PCR, cloning, or reverse transcriptase errors. Recently, a rat cDNA component was added to the project, and ongoing frog (Xenopus) and zebrafish (Danio) cDNA projects were expanded to take advantage of the high-throughput MGC pipeline.

    Funded by: PHS HHS: N01-C0-12400

    Genome research 2004;14;10B;2121-7

  • Par-1 promotes a hepatic mode of apical protein trafficking in MDCK cells.

    Cohen D, Rodriguez-Boulan E and Müsch A

    Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, NY 10021, USA.

    Simple (i.e., nonstratified) epithelial cells use two different routes to target their newly synthesized luminal plasma membrane proteins to the cell surface: a direct route from the Golgi complex, as in the kidney-derived MDCK cell line, or an indirect route that involves a intermediate stop at the ab-luminal (basolateral) membrane, as in hepatocytes. The mechanisms or proteins responsible for these different protein targeting strategies are not known. Here, we show that increased expression of EMK1, a mammalian ortholog of Caenorhabditis elegans Par-1, in MDCK cells promotes a switch from a direct to a transcytotic mode of apical protein delivery and other trafficking changes typical of hepatocytes. These results, together with our recent demonstration that PAR-1 promotes morphological features of hepatocytes in MDCK cells, indicate that Par-1 modulates the developmental decision to build a columnar versus a hepatic epithelial cell. To our knowledge, Par-1 is the first gene assigned to this task in epithelial morphogenesis.

    Funded by: NIGMS NIH HHS: R01 GM034107, R01 GM34107

    Proceedings of the National Academy of Sciences of the United States of America 2004;101;38;13792-7

  • aPKC acts upstream of PAR-1b in both the establishment and maintenance of mammalian epithelial polarity.

    Suzuki A, Hirata M, Kamimura K, Maniwa R, Yamanaka T, Mizuno K, Kishikawa M, Hirose H, Amano Y, Izumi N, Miwa Y and Ohno S

    Department of Molecular Biology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan. abell@med.yokohama-cu.ac.jp

    Background: aPKC and PAR-1 are required for cell polarity in various contexts. In mammalian epithelial cells, aPKC localizes at tight junctions (TJs) and plays an indispensable role in the development of asymmetric intercellular junctions essential for the establishment and maintenance of apicobasal polarity. On the other hand, one of the mammalian PAR-1 kinases, PAR-1b/EMK1/MARK2, localizes to the lateral membrane in a complimentary manner with aPKC, but little is known about its role in apicobasal polarity of epithelial cells as well as its functional relationship with aPKC.

    Results: We demonstrate that PAR-1b is essential for the asymmetric development of membrane domains of polarized MDCK cells. Nonetheless, it is not required for the junctional localization of aPKC nor the formation of TJs, suggesting that PAR-1b works downstream of aPKC during epithelial cell polarization. On the other hand, aPKC phosphorylates threonine 595 of PAR-1b and enhances its binding with 14-3-3/PAR-5. In polarized MDCK cells, T595 phosphorylation and 14-3-3 binding are observed only in the soluble form of PAR-1b, and okadaic acid treatment induces T595-dependent dissociation of PAR-1b from the lateral membrane. Furthermore, T595A mutation induces not only PAR-1b leakage into the apical membrane, but also abnormal development of membrane domains. These results suggest that in polarized epithelial cells, aPKC phosphorylates PAR-1b at TJs, and in cooperation with 14-3-3, promotes the dissociation of PAR-1b from the lateral membrane to regulate PAR-1b activity for the membrane domain development.

    Conclusions: These results suggest that mammalian aPKC functions upstream of PAR-1b in both the establishment and maintenance of epithelial cell polarity.

    Current biology : CB 2004;14;16;1425-35

  • Large-scale characterization of HeLa cell nuclear phosphoproteins.

    Beausoleil SA, Jedrychowski M, Schwartz D, Elias JE, Villén J, Li J, Cohn MA, Cantley LC and Gygi SP

    Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.

    Determining the site of a regulatory phosphorylation event is often essential for elucidating specific kinase-substrate relationships, providing a handle for understanding essential signaling pathways and ultimately allowing insights into numerous disease pathologies. Despite intense research efforts to elucidate mechanisms of protein phosphorylation regulation, efficient, large-scale identification and characterization of phosphorylation sites remains an unsolved problem. In this report we describe an application of existing technology for the isolation and identification of phosphorylation sites. By using a strategy based on strong cation exchange chromatography, phosphopeptides were enriched from the nuclear fraction of HeLa cell lysate. From 967 proteins, 2,002 phosphorylation sites were determined by tandem MS. This unprecedented large collection of sites permitted a detailed accounting of known and unknown kinase motifs and substrates.

    Funded by: NHGRI NIH HHS: HG00041, K22 HG000041, T32 HG000041; NIGMS NIH HHS: GM67945, GMS6203, R01 GM056203, R01 GM067945

    Proceedings of the National Academy of Sciences of the United States of America 2004;101;33;12130-5

  • Comprehensive proteomic analysis of interphase and mitotic 14-3-3-binding proteins.

    Meek SE, Lane WS and Piwnica-Worms H

    Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts 02138, USA.

    14-3-3 proteins regulate the cell division cycle and play a pivotal role in blocking cell cycle advancement after activation of the DNA replication and DNA damage checkpoints. Here we describe a global proteomics analysis to identify proteins that bind to 14-3-3s during interphase and mitosis. 14-3-3-binding proteins were purified from extracts of interphase and mitotic HeLa cells using specific peptide elution from 14-3-3 zeta affinity columns. Proteins that specifically bound and eluted from the affinity columns were identified by microcapillary high pressure liquid chromatography tandem mass spectrometry analysis. Several known and novel 14-3-3-interacting proteins were identified in this screen. Identified proteins are involved in cell cycle regulation, signaling, metabolism, protein synthesis, nucleic acid binding, chromatin structure, protein folding, proteolysis, nucleolar function, and nuclear transport as well as several other cellular processes. In some cases 14-3-3 binding was cell cycle-dependent, whereas in other cases the binding was shown to be cell cycle-independent. This study adds to the growing list of human 14-3-3-binding proteins and implicates a role for 14-3-3 proteins in a plethora of essential biological processes.

    The Journal of biological chemistry 2004;279;31;32046-54

  • Splicing alterations in human renal allografts: detection of a new splice variant of protein kinase Par1/Emk1 whose expression is associated with an increase of inflammation in protocol biopsies of transplanted patients.

    Hueso M, Beltran V, Moreso F, Ciriero E, Fulladosa X, Grinyó JM, Serón D and Navarro E

    Centre d'Oncologia Molecular, Institut de Recerca Oncológica (COM-IRO), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona E08907, Spain.

    Protein kinase Emk1/Par1 (GenBank accession no. X97630) has been identified as a regulator of the immune system homeostasis. Since immunological factors are critical for the development of chronic allograft nephropathy (CAN), we reasoned that expression of Par1/Emk1 could be altered in kidney allografts undergoing CAN. In this paper, we have analysed the association among renal allograft lesions and expression of Par1/Emk1, studied by RT-PCR on total RNA from 51 protocol biopsies of transplanted kidneys, five normal kidneys, and five dysfunctional allografts. The most significant result obtained has been the detection of alterations in the normal pattern of alternative splicing of the Par1/Emk1 transcript, alterations that included loss of expression of constitutively expressed isoforms, and the inclusion of a cryptic exon to generate a new Emk1 isoform (Emk1C). Expression of Emk1C was associated with an increase in the extension of the interstitial infiltrate (0.88+/-0.33 in Emk1C([+]) vs. 0.41+/-0.50 in Emk1C([-]); P<0.011), and with a trend to display higher interstitial scarring (0.66+/-0.70 vs. 0.29+/-0.52; P=0.09) in protocol biopsies when evaluated according to the Banff schema. Moreover, a higher mean arterial pressure (MAP) was also observed (110+/-11 vs. 99+/-11 mm Hg; P=0.012). From these results we propose that Par1/Emk1 could have a role in the development of CAN in kidney allografts.

    Biochimica et biophysica acta 2004;1689;1;58-65

  • Comprehensive proteomic analysis of human Par protein complexes reveals an interconnected protein network.

    Brajenovic M, Joberty G, Küster B, Bouwmeester T and Drewes G

    Cellzome AG, Meyerhofstrasse 1, D-69117 Heidelberg, Germany.

    The polarization of eukaryotic cells is controlled by the concerted activities of asymmetrically localized proteins. The PAR proteins, first identified in Caenorhabditis elegans, are common regulators of cell polarity conserved from nematode and flies to man. However, little is known about the molecular mechanisms by which these proteins and protein complexes establish cell polarity in mammals. We have mapped multiprotein complexes formed around the putative human Par orthologs MARK4 (microtubule-associated protein/microtubule affinity-regulating kinase 4) (Par-1), Par-3, LKB1 (Par-4), 14-3-3zeta and eta (Par-5), Par-6a, -b, -c, and PKClambda (PKC3). We employed a proteomic approach comprising tandem affinity purification (TAP) of protein complexes from cultured cells and protein sequencing by tandem mass spectrometry. From these data we constructed a highly interconnected protein network consisting of three core complex "modules" formed around MARK4 (Par-1), Par-3.Par-6, and LKB1 (Par-4). The network confirms most previously reported interactions. In addition we identified more than 50 novel interactors, some of which, like the 14-3-3 phospho-protein scaffolds, occur in more than one distinct complex. We demonstrate that the complex formation between LKB1.Par-4, PAPK, and Mo25 results in the translocation of LKB1 from the nucleus to the cytoplasm and to tight junctions and show that the LKB1 complex may activate MARKs, which are known to introduce 14-3-3 binding sites into several substrates. Our findings suggest co-regulation and/or signaling events between the distinct Par complexes and provide a basis for further elucidation of the molecular mechanisms that govern cell polarity.

    The Journal of biological chemistry 2004;279;13;12804-11

  • LKB1 is a master kinase that activates 13 kinases of the AMPK subfamily, including MARK/PAR-1.

    Lizcano JM, Göransson O, Toth R, Deak M, Morrice NA, Boudeau J, Hawley SA, Udd L, Mäkelä TP, Hardie DG and Alessi DR

    MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, UK.

    We recently demonstrated that the LKB1 tumour suppressor kinase, in complex with the pseudokinase STRAD and the scaffolding protein MO25, phosphorylates and activates AMP-activated protein kinase (AMPK). A total of 12 human kinases (NUAK1, NUAK2, BRSK1, BRSK2, QIK, QSK, SIK, MARK1, MARK2, MARK3, MARK4 and MELK) are related to AMPK. Here we demonstrate that LKB1 can phosphorylate the T-loop of all the members of this subfamily, apart from MELK, increasing their activity >50-fold. LKB1 catalytic activity and the presence of MO25 and STRAD are required for activation. Mutation of the T-loop Thr phosphorylated by LKB1 to Ala prevented activation, while mutation to glutamate produced active forms of many of the AMPK-related kinases. Activities of endogenous NUAK2, QIK, QSK, SIK, MARK1, MARK2/3 and MARK4 were markedly reduced in LKB1-deficient cells. Neither LKB1 activity nor that of AMPK-related kinases was stimulated by phenformin or AICAR, which activate AMPK. Our results show that LKB1 functions as a master upstream protein kinase, regulating AMPK-related kinases as well as AMPK. Between them, these kinases may mediate the physiological effects of LKB1, including its tumour suppressor function.

    The EMBO journal 2004;23;4;833-43

  • A physical and functional map of the human TNF-alpha/NF-kappa B signal transduction pathway.

    Bouwmeester T, Bauch A, Ruffner H, Angrand PO, Bergamini G, Croughton K, Cruciat C, Eberhard D, Gagneur J, Ghidelli S, Hopf C, Huhse B, Mangano R, Michon AM, Schirle M, Schlegl J, Schwab M, Stein MA, Bauer A, Casari G, Drewes G, Gavin AC, Jackson DB, Joberty G, Neubauer G, Rick J, Kuster B and Superti-Furga G

    Cellzome AG, Meyerhofstrasse 1, 69117 Heidelberg, Germany. tewis.bouwmeester@cellzome.com

    Signal transduction pathways are modular composites of functionally interdependent sets of proteins that act in a coordinated fashion to transform environmental information into a phenotypic response. The pro-inflammatory cytokine tumour necrosis factor (TNF)-alpha triggers a signalling cascade, converging on the activation of the transcription factor NF-kappa B, which forms the basis for numerous physiological and pathological processes. Here we report the mapping of a protein interaction network around 32 known and candidate TNF-alpha/NF-kappa B pathway components by using an integrated approach comprising tandem affinity purification, liquid-chromatography tandem mass spectrometry, network analysis and directed functional perturbation studies using RNA interference. We identified 221 molecular associations and 80 previously unknown interactors, including 10 new functional modulators of the pathway. This systems approach provides significant insight into the logic of the TNF-alpha/NF-kappa B pathway and is generally applicable to other pathways relevant to human disease.

    Nature cell biology 2004;6;2;97-105

  • PAR-1 is a Dishevelled-associated kinase and a positive regulator of Wnt signalling.

    Sun TQ, Lu B, Feng JJ, Reinhard C, Jan YN, Fantl WJ and Williams LT

    Cardiovascular Research Institute, University of California, San Francisco, California, USA.

    Wnt signalling regulates beta-catenin-dependent developmental processes through the Dishevelled protein (Dsh). Dsh regulates two distinct pathways, one mediated by beta-catenin and the other by Jun kinase (JNK). We have purified a Dsh-associated kinase from Drosophila that encodes a homologue of Caenorhabditis elegans PAR-1, a known determinant of polarity during asymmetric cell divisions. Treating cells with Wnt increases endogenous PAR-1 activity coincident with Dsh phosphorylation. PAR-1 potentiates Wnt activation of the beta-catenin pathway but blocks the JNK pathway. Suppressing endogenous PAR-1 function inhibits Wnt signalling through beta-catenin in mammalian cells, and Xenopus and Drosophila embryos. PAR-1 seems to be a positive regulator of the beta-catenin pathway and an inhibitor of the JNK pathway. These findings show that PAR-1, a regulator of polarity, is also a modulator of Wnt-beta-catenin signalling, indicating a link between two important developmental pathways.

    Funded by: NHLBI NIH HHS: P0 HL43821

    Nature cell biology 2001;3;7;628-36

  • Atypical protein kinase C is involved in the evolutionarily conserved par protein complex and plays a critical role in establishing epithelia-specific junctional structures.

    Suzuki A, Yamanaka T, Hirose T, Manabe N, Mizuno K, Shimizu M, Akimoto K, Izumi Y, Ohnishi T and Ohno S

    Department of Molecular Biology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan.

    We have previously shown that during early Caenorhabditis elegans embryogenesis PKC-3, a C. elegans atypical PKC (aPKC), plays critical roles in the establishment of cell polarity required for subsequent asymmetric cleavage by interacting with PAR-3 [Tabuse, Y., Y. Izumi, F. Piano, K.J. Kemphues, J. Miwa, and S. Ohno. 1998. Development (Camb.). 125:3607--3614]. Together with the fact that aPKC and a mammalian PAR-3 homologue, aPKC-specific interacting protein (ASIP), colocalize at the tight junctions of polarized epithelial cells (Izumi, Y., H. Hirose, Y. Tamai, S.-I. Hirai, Y. Nagashima, T. Fujimoto, Y. Tabuse, K.J. Kemphues, and S. Ohno. 1998. J. Cell Biol. 143:95--106), this suggests a ubiquitous role for aPKC in establishing cell polarity in multicellular organisms. Here, we show that the overexpression of a dominant-negative mutant of aPKC (aPKCkn) in MDCK II cells causes mislocalization of ASIP/PAR-3. Immunocytochemical analyses, as well as measurements of paracellular diffusion of ions or nonionic solutes, demonstrate that the biogenesis of the tight junction structure itself is severely affected in aPKCkn-expressing cells. Furthermore, these cells show increased interdomain diffusion of fluorescent lipid and disruption of the polarized distribution of Na(+),K(+)-ATPase, suggesting that epithelial cell surface polarity is severely impaired in these cells. On the other hand, we also found that aPKC associates not only with ASIP/PAR-3, but also with a mammalian homologue of C. elegans PAR-6 (mPAR-6), and thereby mediates the formation of an aPKC-ASIP/PAR-3-PAR-6 ternary complex that localizes to the apical junctional region of MDCK cells. These results indicate that aPKC is involved in the evolutionarily conserved PAR protein complex, and plays critical roles in the development of the junctional structures and apico-basal polarization of mammalian epithelial cells.

    The Journal of cell biology 2001;152;6;1183-96

  • Precise localization of D11S1226 to the human EMK1 gene at chromosome band 11q13 by sequence homology search.

    Navarro E

    UBCM-Institut Municipal d'Investigació Mèdica, Barcelona, Spain. enavarro@imim.es

    Cytogenetics and cell genetics 1999;86;1;66-7

  • Human serine/threonine protein kinase EMK1: genomic structure and cDNA cloning of isoforms produced by alternative splicing.

    Espinosa L and Navarro E

    UBCM-Institut Municipal d'Investigació Mèdica, Barcelona, Spain.

    The EMK (ELKL Motif Kinase) is a small family of ser/thr protein kinases involved in the control of cell polarity, microtubule stability and cancer. We have isolated several cDNA clones that encoded two isoforms of the human ser/thr protein kinase EMK1 (GDB symbol EMK1, alias ELKL motif kinase 1, and MARK2). These isoforms were characterized by the presence of a 162-bp alternative exon that gave rise to two forms, one containing the exon and the other one lacking it. Both forms were found to be coexpressed in a number of selected cell lines and tissue samples when analyzed by RT-PCR. By Northern blot, human EMK1 was shown to be encoded by a single mRNA ubiquitously expressed. We have reconstructed most of the genomic structure of EMK1 from the sequence of two human chromosome 11 cosmids deposited in databases, and showed that the gene is composed of a minimum of 16 small exons.

    Cytogenetics and cell genetics 1998;81;3-4;278-82

  • Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library.

    Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, Suyama A and Sugano S

    International and Interdisciplinary Studies, The University of Tokyo, Japan.

    Using 'oligo-capped' mRNA [Maruyama, K., Sugano, S., 1994. Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides. Gene 138, 171-174], whose cap structure was replaced by a synthetic oligonucleotide, we constructed two types of cDNA library. One is a 'full length-enriched cDNA library' which has a high content of full-length cDNA clones and the other is a '5'-end-enriched cDNA library', which has a high content of cDNA clones with their mRNA start sites. The 5'-end-enriched library was constructed especially for isolating the mRNA start sites of long mRNAs. In order to characterize these libraries, we performed one-pass sequencing of randomly selected cDNA clones from both libraries (84 clones for the full length-enriched cDNA library and 159 clones for the 5'-end-enriched cDNA library). The cDNA clones of the polypeptide chain elongation factor 1 alpha were most frequently (nine clones) isolated, and more than 80% of them (eight clones) contained the mRNA start site of the gene. Furthermore, about 80% of the cDNA clones of both libraries whose sequence matched with known genes had the known 5' ends or sequences upstream of the known 5' ends (28 out of 35 for the full length-enriched library and 51 out of 62 for the 5'-end-enriched library). The longest full-length clone of the full length-enriched cDNA library was about 3300 bp (among 28 clones). In contrast, seven clones (out of the 51 clones with the mRNA start sites) from the 5'-end-enriched cDNA library came from mRNAs whose length is more than 3500 bp. These cDNA libraries may be useful for generating 5' ESTs with the information of the mRNA start sites that are now scarce in the EST database.

    Gene 1997;200;1-2;149-56

  • MARK, a novel family of protein kinases that phosphorylate microtubule-associated proteins and trigger microtubule disruption.

    Drewes G, Ebneth A, Preuss U, Mandelkow EM and Mandelkow E

    Max-Planck-Unit for Structural Molecular Biology, Hamburg, Germany.

    MARK phosphorylates the microtubule-associated proteins tau, MAP2, and MAP4 on their microtubule-binding domain, causing their dissociation from microtubules and increased microtubule dynamics. We describe the molecular cloning, distribution, activation mechanism, and overexpression of two MARK proteins from rat that arise from distinct genes. They encode Ser/Thr kinases of 88 and 81 kDa, respectively, and show similarity to the yeast kin1+ and C. elegans par-1 genes that are involved in the establishment of cell polarity. Expression of both isoforms is ubiquitous, and homologous genes are present in humans. Catalytic activity depends on phosphorylation of two residues in subdomain VIII. Overexpression of MARK in cells leads to hyperphosphorylation of MAPs on KXGS motifs and to disruption of the microtubule array, resulting in morphological changes and cell death.

    Cell 1997;89;2;297-308

  • Definition of the minimal MEN1 candidate area based on a 5-Mb integrated map of proximal 11q13. The European Consortium on Men1, (GENEM 1; Groupe d'Etude des Néoplasies Endocriniennes Multiples de type 1).

    Courseaux A, Grosgeorge J, Gaudray P, Pannett AA, Forbes SA, Williamson C, Bassett D, Thakker RV, Teh BT, Farnebo F, Shepherd J, Skogseid B, Larsson C, Giraud S, Zhang CX, Salandre J and Calender A

    LGMCH, CNRS URA 1462, Nice, France. courseaux@unice.fr

    Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder with a high penetrance characterized by tumors of the parathyroid glands, the endocrine pancreas, and the anterior pituitary. The MEN1 gene, a putative tumor suppressor gene, has been mapped to a 3- to 8-cM region in chromosome 11q13 but it remains elusive as yet. We have combined the efforts and resources from four laboratories to form the European Consortium on MEN1 with the aims of establishing the genetic and the physical maps of 11q13 and of further narrowing the MEN1 region. A 5-Mb integrated map of the region was established by fluorescence in situ hybridization on both metaphase chromosomes and DNA fibers, by hybridization to DNA from somatic cell hybrids containing various parts of human chromosome 11, by long-range restriction mapping, and by characterization of YACs and cosmids. Polymorphic markers were positioned and ordered by physical mapping and genetic linkage in 86 MEN1 families with 452 affected individuals. Two critical recombinants identified in two affected cases placed the MEN1 gene in an approximately 2-Mb region around PYGM, flanked by D11S1883 and D11S449.

    Genomics 1996;37;3;354-65

  • Human EMK1 is located on 11q12-q13, close to COX8 and FTH1.

    Courseaux A, Fernandes M, Grosgeorge J, Inglis J, Raynaud SD and Gaudray P

    LGMCH, CNRS URA 1462, Faculté de Médecine, Nice, France.

    Mammalian genome : official journal of the International Mammalian Genome Society 1995;6;4;311-2

  • Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides.

    Maruyama K and Sugano S

    Institute of Medical Science, University of Tokyo, Japan.

    We have devised a method to replace the cap structure of a mRNA with an oligoribonucleotide (r-oligo) to label the 5' end of eukaryotic mRNAs. The method consists of removing the cap with tobacco acid pyrophosphatase (TAP) and ligating r-oligos to decapped mRNAs with T4 RNA ligase. This reaction was made cap-specific by removing 5'-phosphates of non-capped RNAs with alkaline phosphatase prior to TAP treatment. Unlike the conventional methods that label the 5' end of cDNAs, this method specifically labels the capped end of the mRNAs with a synthetic r-oligo prior to first-strand cDNA synthesis. The 5' end of the mRNA was identified quite simply by reverse transcription-polymerase chain reaction (RT-PCR).

    Gene 1994;138;1-2;171-4

  • Identification of 21 novel human protein kinases, including 3 members of a family related to the cell cycle regulator nimA of Aspergillus nidulans.

    Schultz SJ and Nigg EA

    Swiss Institute for Experimental Cancer Research, Epalinges.

    The nimA gene encodes a protein-serine/threonine kinase that is required along with the p34cdc2 kinase for mitosis in Aspergillus nidulans. We have searched for human protein kinases that are related to the NIMA protein kinase using the polymerase chain reaction. Different pairs of degenerate oligonucleotides specific for conserved amino acid motifs in the catalytic domain of NIMA were used as primers in the polymerase chain reaction to amplify partial complementary DNAs (cDNAs) of protein kinases expressed in the promyelocytic leukemia cell line HL-60. Forty-one distinct cDNAs representing a broad spectrum of serine/threonine- and tyrosine-specific protein kinases were identified, and the sequences for 21 of these protein kinases were found to be unique. Three of these cDNAs represent a family of protein kinases whose members are related to NIMA and the murine nimA-related protein kinase Nek1. We discuss the success of this polymerase chain reaction approach with respect to the use of multiple primer pairs, the influence of primer degeneracy, and the tolerance of cDNA amplification to mismatches between primers and template mRNA.

    Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research 1993;4;10;821-30

Gene lists (6)

Gene List Source Species Name Description Gene count
L00000009 G2C Homo sapiens Human PSD Human orthologues of mouse PSD adapted from Collins et al (2006) 1080
L00000016 G2C Homo sapiens Human PSP Human orthologues of mouse PSP adapted from Collins et al (2006) 1121
L00000059 G2C Homo sapiens BAYES-COLLINS-HUMAN-PSD-CONSENSUS Human cortex PSD consensus 748
L00000061 G2C Homo sapiens BAYES-COLLINS-MOUSE-PSD-CONSENSUS Mouse cortex PSD consensus (ortho) 984
L00000069 G2C Homo sapiens BAYES-COLLINS-HUMAN-PSD-FULL Human cortex biopsy PSD full list 1461
L00000071 G2C Homo sapiens BAYES-COLLINS-MOUSE-PSD-FULL Mouse cortex PSD full list (ortho) 1556
© G2C 2014. The Genes to Cognition Programme received funding from The Wellcome Trust and the EU FP7 Framework Programmes:
EUROSPIN (FP7-HEALTH-241498), SynSys (FP7-HEALTH-242167) and GENCODYS (FP7-HEALTH-241995).

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