G2Cdb::Gene report

Gene id
Gene symbol
Homo sapiens
abl-interactor 1
G00000596 (Mus musculus)

Databases (8)

Curated Gene
OTTHUMG00000017848 (Vega human gene)
ENSG00000136754 (Ensembl human gene)
10006 (Entrez Gene)
1038 (G2Cdb plasticity & disease)
ABI1 (GeneCards)
603050 (OMIM)
Marker Symbol
HGNC:11320 (HGNC)
Protein Sequence
Q8IZP0 (UniProt)

Synonyms (2)

  • ABI-1
  • E3B1

Literature (45)

Pubmed - other

  • Abl interactor 1 regulates Src-Id1-matrix metalloproteinase 9 axis and is required for invadopodia formation, extracellular matrix degradation and tumor growth of human breast cancer cells.

    Sun X, Li C, Zhuang C, Gilmore WC, Cobos E, Tao Y and Dai Z

    Department of Internal Medicine, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA.

    Abl interactor 1 (Abi1) is a key regulator of actin polymerization/depolymerization. The involvement of Abi1 in the development of abnormal cytoskeletal functions of cancer cells has recently been reported. It remains unclear, however, how Abi1 exerts its effects in tumor cells and whether it contributes to tumor progression in vivo. We report here a novel function for Abi1 in the regulation of invadopodia formation and Src-inhibitor of differentiation protein 1 (Id1)-matrix metalloproteinase (MMP)-9 pathway in MDA-MB-231 human breast cancer cells. Abi1 is found in the invadopodia of MDA-MB-231 cells. Epigenetic silencing of the Abi1 gene by short hairpin RNA in MDA-MB-231 cells impaired the formation of invadopodia and resulted in downregulation of the Src activation and Id1/MMP-9 expression. The decreased invadopodia formation and MMP-9 expression correlate with a reduction in the ability of these cells to degrade extracellular matrix. Remarkably, the knockdown of Abi1 expression inhibited tumor cell proliferation and migration in vitro and slowed tumor growth in vivo. Taken together, these results indicate that the Abi1 signaling plays a critical role in breast cancer progression and suggest that this pathway may serve as a therapeutic target for the treatment of human breast cancer.

    Funded by: NCI NIH HHS: R01 CA094921, R01 CA094921-06, R21 CA133597, R21 CA133597-01A1; NIDDK NIH HHS: K01 DK067191

    Carcinogenesis 2009;30;12;2109-16

  • Regulation of cell-cell adhesion by Abi/Diaphanous complexes.

    Ryu JR, Echarri A, Li R and Pendergast AM

    Department of Pharmacology and Cancer Biology, Duke University Medical Center, Box 3813, Durham, North Carolina 27710, USA.

    Actin polymerization provides the driving force for the formation of cell-cell junctions and is mediated by two types of actin nucleators, Arp2/3 and formins. Proteins required for coordinately linking cadherin-mediated adhesion to Arp2/3-dependent versus formin-dependent nucleation have yet to be defined. Here we show a role for Abi, the Abi-binding partner Nap1, and the Nap1-binding protein Sra1 in the regulation of cadherin-dependent adhesion. We found that Abi, which is known to interact with Wave, leading to activation of the Arp2/3 complex, is also capable of interacting with the Diaphanous (Dia)-related formins in the absence of Wave. Knockdown of Abi, Nap1, Sra1, or Dia markedly inhibited cell-cell junctions, whereas knockdown of Wave or Arp2/3 produced mild and transient phenotypes. Dia and Abi colocalized with beta-catenin at cell-cell junctions. Further, Dia and Wave bound to overlapping sites on Abi1, and Wave competed with Dia for Abi1 binding. Notably, an active Dia1 C-terminal fragment that localizes to cell-cell junctions rescued the abnormal junctions induced by depletion of Abi or Nap1 in epithelial cells. These findings uncover a novel link between cadherin-mediated adhesion and the regulation of actin dynamics through the requirement for an Abi/Dia complex for the formation and stability of cell-cell junctions.

    Funded by: NCI NIH HHS: CA 70940, R01 CA070940; NHLBI NIH HHS: HL 084102, R01 HL084102; NIAID NIH HHS: AI 56266, R01 AI056266

    Molecular and cellular biology 2009;29;7;1735-48

  • Allosteric inhibition of the nonMyristoylated c-Abl tyrosine kinase by phosphopeptides derived from Abi1/Hssh3bp1.

    Xiong X, Cui P, Hossain S, Xu R, Warner B, Guo X, An X, Debnath AK, Cowburn D and Kotula L

    Laboratory of Cell Signaling, New York Blood Center, New York, NY 10065, USA.

    Here we report c-Abl kinase inhibition mediated by a phosphotyrosine located in trans in the c-Abl substrate, Abi1. The mechanism, which is pertinent to the nonmyristoylated c-Abl kinase, involves high affinity concurrent binding of the phosphotyrosine pY213 to the Abl SH2 domain and binding of a proximal PXXP motif to the Abl SH3 domain. Abi1 regulation of c-Abl in vivo appears to play a critical role, as demonstrated by inhibition of pY412 phosphorylation of the nonmyristoylated Abl by coexpression of Abi1. Pervanadate-induced c-Abl kinase activity was also reduced upon expression of the wild type Abi1 but not by expression of the Y213 to F213 mutant Abi1 in LNCaP cells, which are naturally deficient in the regulatory pY213. Our findings suggest a novel mechanism by which Abl kinase is regulated in cells.

    Funded by: NIGMS NIH HHS: GM 47021, R01 GM047021, R01 GM047021-16; NINDS NIH HHS: NS 44968, R01 NS044968, R01 NS044968-01A1, R01 NS044968-02, R01 NS044968-03, R01 NS044968-04

    Biochimica et biophysica acta 2008;1783;5;737-47

  • MT1-MMP as a downstream target of BCR-ABL/ABL interactor 1 signaling: polarized distribution and involvement in BCR-ABL-stimulated leukemic cell migration.

    Sun X, Li Y, Yu W, Wang B, Tao Y and Dai Z

    Funded by: NCI NIH HHS: R01 CA094921, R01 CA094921-01A1, R01 CA094921-02, R01 CA094921-03, R01 CA094921-04, R01 CA094921-05, R01 CA094921-06; NIDDK NIH HHS: K01 DK067191, K01 DK067191-03, K01 DK067191-04

    Leukemia 2008;22;5;1053-6

  • Abelson interactor protein-1 positively regulates breast cancer cell proliferation, migration, and invasion.

    Wang C, Navab R, Iakovlev V, Leng Y, Zhang J, Tsao MS, Siminovitch K, McCready DR and Done SJ

    Division of Applied Molecular Oncology, Ontario Cancer Institute, Toronto, Ontario, Canada.

    Abelson interactor protein-1 (ABI-1) is an adaptor protein involved in actin reorganization and lamellipodia formation. It forms a macromolecular complex containing Hspc300/WASP family verprolin-homologous proteins 2/ABI-1/nucleosome assembly protein 1/PIR121 or Abl/ABI-1/WASP family verprolin-homologous proteins 2 in response to Rho family-dependent stimuli. Due to its role in cell mobility, we hypothesized that ABI-1 has a role in invasion and metastasis. In the present study, we found that weakly invasive breast cancer cell lines (MCF-7, T47D, MDA-MB-468, SKBR3, and CAMA1) express lower levels of ABI-1 compared with highly invasive breast cancer cell lines (MDA-MB-231, MDA-MB-157, BT549, and Hs578T), which exhibit high ABI-1 levels. Using RNA interference, ABI-1 was stably down-regulated in MDA-MB-231, which resulted in decreased cell proliferation and anchorage-dependent colony formation and abrogation of lamellipodia formation on fibronectin. Down-regulation of ABI-1 decreased invasiveness and migration ability and decreased adhesion on collagen IV and actin polymerization in MDA-MB-231 cells. Additionally, compared with control parental cells, ABI-1 small interfering RNA-transfected cells showed decreased levels of phospho-PDK1, phospho-Raf, phospho-AKT, total AKT, and AKT1. These data suggest that ABI-1 plays an important role in the spread of breast cancer and that this role may be mediated via the phosphatidylinositol 3-kinase pathway.

    Molecular cancer research : MCR 2007;5;10;1031-9

  • Rac interacts with Abi-1 and WAVE2 to promote an Arp2/3-dependent actin recruitment during chlamydial invasion.

    Carabeo RA, Dooley CA, Grieshaber SS and Hackstadt T

    Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, KY, USA.

    Chlamydiae are Gram-negative obligate intracellular pathogens to which access to an intracellular environment is fundamental to their development. Chlamydial attachment to host cells induces the activation of the Rac GTPase, which is required for the localization of WAVE2 at the sites of chlamydial entry. Co-immunoprecipitation experiments demonstrated that Chlamydia trachomatis infection promoted the interaction of Rac with WAVE2 and Abi-1, but not with IRSp53. siRNA depletion of WAVE2 and Abi-1 abrogated chlamydia-induced actin recruitment and significantly reduced the uptake of the pathogen by the depleted cells. Chlamydia invasion also requires the Arp2/3 complex as demonstrated by its localization to the sites of chlamydial attachment and the reduced efficiency of chlamydial invasion in cells overexpressing the VCA domain of the neural Wiskott-Aldrich syndrome protein. Thus, C. trachomatis activates Rac and promotes its interaction with WAVE2 and Abi-1 to activate the Arp2/3 complex resulting in the induction of actin cytoskeletal rearrangements that are required for invasion.

    Funded by: Intramural NIH HHS; NIAID NIH HHS: AI065545, K22 AI052252, K22 AI052252-02, R01 AI065545, R01 AI065545-01

    Cellular microbiology 2007;9;9;2278-88

  • NESH (Abi-3) is present in the Abi/WAVE complex but does not promote c-Abl-mediated phosphorylation.

    Hirao N, Sato S, Gotoh T, Maruoka M, Suzuki J, Matsuda S, Shishido T and Tani K

    School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.

    Abl interactor (Abi) was identified as an Abl tyrosine kinase-binding protein and subsequently shown to be a component of the macromolecular Abi/WAVE complex, which is a key regulator of Rac-dependent actin polymerization. Previous studies showed that Abi-1 promotes c-Abl-mediated phosphorylation of Mammalian Enabled (Mena) and WAVE2. In addition to Abi-1, mammals possess Abi-2 and NESH (Abi-3). In this study, we compared the three Abi proteins in terms of the promotion of c-Abl-mediated phosphorylation and the formation of Abi/WAVE complex. Although Abi-2, like Abi-1, promoted the c-Abl-mediated phosphorylation of Mena and WAVE2, NESH (Abi-3) had no such effect. This difference was likely due to their binding abilities as to c-Abl. Immunoprecipitation revealed that NESH (Abi-3) is present in the Abi/WAVE complex. Our results suggest that NESH (Abi-3), like Abi-1 and Abi-2, is a component of the Abi/WAVE complex, but likely plays a different role in the regulation of c-Abl.

    FEBS letters 2006;580;27;6464-70

  • 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

  • c-Abl interacts with the WAVE2 signaling complex to induce membrane ruffling and cell spreading.

    Stuart JR, Gonzalez FH, Kawai H and Yuan ZM

    Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts 02115, USA.

    The Wiskott-Aldrich syndrome-related protein WAVE2 promotes Arp2/3-dependent actin polymerization downstream of Rho-GTPase activation. The Abelson-interacting protein-1 (Abi-1) forms the core of the WAVE2 complex and is necessary for proper stimulation of WAVE2 activity. Here we have shown that the Abl-tyrosine kinase interacts with the WAVE2 complex and that Abl kinase activity facilitates interaction between Abl and WAVE2 complex members. We have characterized various interactions between Abl and members of the WAVE2 complex and revealed that Abi-1 promotes interaction between Abl and WAVE2 members. We have demonstrated that Abl-dependent phosphorylation of WAVE2 is necessary for its activation in vivo, which is highlighted by the findings that RNA interference of WAVE2 expression in Abl/Arg-/- cells has no additive effect on the amount of membrane ruffling. Furthermore, Abl phosphorylates WAVE2 on tyrosine 150, and WAVE2-deficient cells rescued with a Y150F mutant fail to regain their ability to ruffle and form microspikes, unlike cells rescued with wild-type WAVE2. Together, these data show that c-Abl activates WAVE2 via tyrosine phosphorylation to promote actin remodeling in vivo and that Abi-1 forms the crucial link between these two factors.

    Funded by: NCI NIH HHS: R29 CA85679

    The Journal of biological chemistry 2006;281;42;31290-7

  • A scan of chromosome 10 identifies a novel locus showing strong association with late-onset Alzheimer disease.

    Grupe A, Li Y, Rowland C, Nowotny P, Hinrichs AL, Smemo S, Kauwe JS, Maxwell TJ, Cherny S, Doil L, Tacey K, van Luchene R, Myers A, Wavrant-De Vrièze F, Kaleem M, Hollingworth P, Jehu L, Foy C, Archer N, Hamilton G, Holmans P, Morris CM, Catanese J, Sninsky J, White TJ, Powell J, Hardy J, O'Donovan M, Lovestone S, Jones L, Morris JC, Thal L, Owen M, Williams J and Goate A

    Celera Diagnostics, Alameda, CA, USA.

    Strong evidence of linkage to late-onset Alzheimer disease (LOAD) has been observed on chromosome 10, which implicates a wide region and at least one disease-susceptibility locus. Although significant associations with several biological candidate genes on chromosome 10 have been reported, these findings have not been consistently replicated, and they remain controversial. We performed a chromosome 10-specific association study with 1,412 gene-based single-nucleotide polymorphisms (SNPs), to identify susceptibility genes for developing LOAD. The scan included SNPs in 677 of 1,270 known or predicted genes; each gene contained one or more markers, about half (48%) of which represented putative functional mutations. In general, the initial testing was performed in a white case-control sample from the St. Louis area, with 419 LOAD cases and 377 age-matched controls. Markers that showed significant association in the exploratory analysis were followed up in several other white case-control sample sets to confirm the initial association. Of the 1,397 markers tested in the exploratory sample, 69 reached significance (P < .05). Five of these markers replicated at P < .05 in the validation sample sets. One marker, rs498055, located in a gene homologous to RPS3A (LOC439999), was significantly associated with Alzheimer disease in four of six case-control series, with an allelic P value of .0001 for a meta-analysis of all six samples. One of the case-control samples with significant association to rs498055 was derived from the linkage sample (P = .0165). These results indicate that variants in the RPS3A homologue are associated with LOAD and implicate this gene, adjacent genes, or other functional variants (e.g., noncoding RNAs) in the pathogenesis of this disorder.

    Funded by: Intramural NIH HHS; Medical Research Council: G0300429, G0701075, G9810900; NHGRI NIH HHS: T32 HG000045; NIA NIH HHS: AG 05146, AG05128, P01 AG003991, P01 AG03991, P50 AG005128, P50 AG005131, P50 AG005146, P50 AG005681, P50 AG008671, P50 AG016570, P50 AG05131, P50 AG05681, P50 AG16570, P50-AG08671, R01 AG016208, R01 AG16208, U24 AG021886; NIGMS NIH HHS: GM065509, P50 GM065509; NIMH NIH HHS: MH60451, P50 MH060451, U01 MH046281, U01 MH046290, U01 MH046373; NINDS NIH HHS: NS39764, P50 NS039764

    American journal of human genetics 2006;78;1;78-88

  • E3B1, a human homologue of the mouse gene product Abi-1, sensitizes activation of Rap1 in response to epidermal growth factor.

    Jenei V, Andersson T, Jakus J and Dib K

    Institute of Biomolecular Chemistry, Chemical Research Centre, Hungarian Academy of Sciences, Pusztaszeri Street 59-67, 1025 Budapest, Hungary.

    E3B1, a human homologue of the mouse gene product Abi-1, has been implicated in growth-factor-mediated regulation of the small GTPases p21Ras and Rac. E3b1 is a regulator of Rac because it can form a complex with Sos-1 and eps8, and such a Sos-1-e3B1-eps8 complex serves as a guanine nucleotide exchange factor for Rac. In the present study, we found that overexpression of e3B1 in NIH3T3/EGFR cells sensitized EGF-induced activation of Rac1, whereas it had no impact on EGF-induced activation of p21Ras. Remarkably, we found that EGF-induced activation of the p21Ras-related GTPase Rap1 was also sensitized in NIH3T3/EGFR-e3B1 cells. Thus, in NIH3T3/EGFR-e3B1 cells, maximal EGF-induced activation of Rap1 occurs with a dose of EGF much lower than in NIH3T3/EGFR cells. We also report that overexpression of e3B1 in NIH3T3/EGFR cells renders EGF-induced activation of Rap1 completely dependent on Src tyrosine kinases but not on c-Abl. However, EGF-induced tyrosine phosphorylation of the Rap GEF C3G occurred regardless of whether e3B1 was overexpressed or not, and this did not involve Src tyrosine kinases. Accordingly, we propose that overexpression of e3B1 in NIH3T3/EGFR cells leads to mobilization of Src tyrosine kinases that participate in EGF-induced activation of Rap1 and inhibition of cell proliferation.

    Experimental cell research 2005;310;2;463-73

  • Regulation of actin cytoskeleton architecture by Eps8 and Abi1.

    Roffers-Agarwal J, Xanthos JB and Miller JR

    Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA. roff0013@umn.edu

    Background: The actin cytoskeleton participates in many fundamental processes including the regulation of cell shape, motility, and adhesion. The remodeling of the actin cytoskeleton is dependent on actin binding proteins, which organize actin filaments into specific structures that allow them to perform various specialized functions. The Eps8 family of proteins is implicated in the regulation of actin cytoskeleton remodeling during cell migration, yet the precise mechanism by which Eps8 regulates actin organization and remodeling remains elusive.

    Results: Here, we show that Eps8 promotes the assembly of actin rich filopodia-like structures and actin cables in cultured mammalian cells and Xenopus embryos, respectively. The morphology of actin structures induced by Eps8 was modulated by interactions with Abi1, which stimulated formation of actin cables in cultured cells and star-like structures in Xenopus. The actin stars observed in Xenopus animal cap cells assembled at the apical surface of epithelial cells in a Rac-independent manner and their formation was accompanied by recruitment of N-WASP, suggesting that the Eps8/Abi1 complex is capable of regulating the localization and/or activity of actin nucleators. We also found that Eps8 recruits Dishevelled to the plasma membrane and actin filaments suggesting that Eps8 might participate in non-canonical Wnt/Polarity signaling. Consistent with this idea, mis-expression of Eps8 in dorsal regions of Xenopus embryos resulted in gastrulation defects.

    Conclusion: Together, these results suggest that Eps8 plays multiple roles in modulating actin filament organization, possibly through its interaction with distinct sets of actin regulatory complexes. Furthermore, the finding that Eps8 interacts with Dsh and induced gastrulation defects provides evidence that Eps8 might participate in non-canonical Wnt signaling to control cell movements during vertebrate development.

    BMC cell biology 2005;6;36

  • WW domains provide a platform for the assembly of multiprotein networks.

    Ingham RJ, Colwill K, Howard C, Dettwiler S, Lim CS, Yu J, Hersi K, Raaijmakers J, Gish G, Mbamalu G, Taylor L, Yeung B, Vassilovski G, Amin M, Chen F, Matskova L, Winberg G, Ernberg I, Linding R, O'donnell P, Starostine A, Keller W, Metalnikov P, Stark C and Pawson T

    Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.

    WW domains are protein modules that mediate protein-protein interactions through recognition of proline-rich peptide motifs and phosphorylated serine/threonine-proline sites. To pursue the functional properties of WW domains, we employed mass spectrometry to identify 148 proteins that associate with 10 human WW domains. Many of these proteins represent novel WW domain-binding partners and are components of multiprotein complexes involved in molecular processes, such as transcription, RNA processing, and cytoskeletal regulation. We validated one complex in detail, showing that WW domains of the AIP4 E3 protein-ubiquitin ligase bind directly to a PPXY motif in the p68 subunit of pre-mRNA cleavage and polyadenylation factor Im in a manner that promotes p68 ubiquitylation. The tested WW domains fall into three broad groups on the basis of hierarchical clustering with respect to their associated proteins; each such cluster of bound proteins displayed a distinct set of WW domain-binding motifs. We also found that separate WW domains from the same protein or closely related proteins can have different specificities for protein ligands and also demonstrated that a single polypeptide can bind multiple classes of WW domains through separate proline-rich motifs. These data suggest that WW domains provide a versatile platform to link individual proteins into physiologically important networks.

    Molecular and cellular biology 2005;25;16;7092-106

  • Identification of B cell adaptor for PI3-kinase (BCAP) as an Abl interactor 1-regulated substrate of Abl kinases.

    Maruoka M, Suzuki J, Kawata S, Yoshida K, Hirao N, Sato S, Goff SP, Takeya T, Tani K and Shishido T

    Laboratory of Molecular Oncology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.

    In previous work we showed that Abl interactor 1 (Abi-1), by linking enzyme and substrate, promotes the phosphorylation of Mammalian Enabled (Mena) by c-Abl. To determine whether this mechanism extends to other c-Abl substrates, we used the yeast two-hybrid system to search for proteins that interact with Abi-1. By screening a human leukocyte cDNA library, we identified BCAP (B-cell adaptor for phosphoinositide 3-kinase) as another Abi-1-interacting protein. Binding experiments revealed that the SH3 domain of Abi-1 and the C-terminal polyproline structure of BCAP are involved in interactions between the two. In cultured cells, Abi-1 promoted phosphorylation of BCAP not only by c-Abl but also by v-Abl. The phosphorylation sites of BCAP by c-Abl were mapped to five tyrosine residues in the C-terminal region that are well conserved in mammals. These results show that Abi-1 promotes Abl-mediated BCAP phosphorylation and suggest that Abi-1 in general coordinates kinase-substrate interactions.

    FEBS letters 2005;579;14;2986-90

  • WASP-related proteins, Abi1 and Ena/VASP are required for Listeria invasion induced by the Met receptor.

    Bierne H, Miki H, Innocenti M, Scita G, Gertler FB, Takenawa T and Cossart P

    Unité des Interactions Bactéries-Cellules, Institut Pasteur, INSERM U604, INRA USC2020, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France.

    Internalisation of the pathogenic bacterium Listeria monocytogenes involves interactions between the invasion protein InlB and the hepatocyte growth factor receptor, Met. Using colocalisation studies, dominant-negative constructs and small interfering RNA (siRNA), we demonstrate a cell-type-dependent requirement for various WASP-related proteins in Listeria entry and InlB-induced membrane ruffling. The WAVE2 isoform is essential for InlB-induced cytoskeletal rearrangements in Vero cells. In HeLa cells, WAVE1, WAVE2 and N-WASP cooperate to promote these processes. Abi1, a key component of WAVE complexes, is recruited at the entry site in both cell types and its inactivation by RNA interference impairs InlB-mediated processes. Ena/VASP proteins also play a role in Listeria internalization, and their deregulation by sequestration or overexpression, modifies actin cups beneath entering particles. Taken together, these results identify the WAVE complex, N-WASP and Ena/VASP as key effectors of the Met signalling pathway and of Listeria entry and highlight the existence of redundant and/or cooperative functions among WASP-family members.

    Funded by: NIGMS NIH HHS: GM58801

    Journal of cell science 2005;118;Pt 7;1537-47

  • Dynamin 2 regulates T cell activation by controlling actin polymerization at the immunological synapse.

    Gomez TS, Hamann MJ, McCarney S, Savoy DN, Lubking CM, Heldebrant MP, Labno CM, McKean DJ, McNiven MA, Burkhardt JK and Billadeau DD

    Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.

    Actin reorganization at the immunological synapse is required for the amplification and generation of a functional immune response. Using small interfering RNA, we show here that dynamin 2 (Dyn2), a large GTPase involved in receptor-mediated internalization, did not alter antibody-mediated T cell receptor internalization but considerably affected T cell receptor-stimulated T cell activation by regulating multiple biochemical signaling pathways and the accumulation of F-actin at the immunological synapse. Moreover, Dyn2 interacted directly with the Rho family guanine nucleotide exchange factor Vav1, and this interaction was required for T cell activation. These data identify a functionally important interaction between Dyn2 and Vav1 that regulates actin reorganization and multiple signaling pathways in T lymphocytes.

    Funded by: NCI NIH HHS: CA47752; NIAID NIH HHS: AI44959

    Nature immunology 2005;6;3;261-70

  • Abelson-interactor-1 promotes WAVE2 membrane translocation and Abelson-mediated tyrosine phosphorylation required for WAVE2 activation.

    Leng Y, Zhang J, Badour K, Arpaia E, Freeman S, Cheung P, Siu M and Siminovitch K

    Departments of Medicine, Immunology, Medical Genetics, and Microbiology, University of Toronto and The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, Canada M5G 1X5.

    WAVE2 is a member of the Wiskott-Aldrich syndrome protein family of cytoskeletal regulatory proteins shown to link Rac activation to actin remodeling via induction of Arp 2/3 activity. WAVE2 is thought to be regulated by its positioning in a macromolecular complex also containing the Abelson-(Abl) interactor-1 (Abi-1) adaptor, but the molecular basis and biologic relevance of WAVE2 inclusion in this complex are ill defined. Here we show that Abi-1 binding to WAVE2 is mediated by discrete motifs in the Abi-1 coiled-coil and WAVE2 WAVE-homology domains and increases markedly in conjunction with Abi-1-WAVE2 translocation and colocalization at the leading edge in B16F1 cells after fibronectin stimulation. Abi-1 also couples WAVE2 to Abl after cell stimulation, an interaction that triggers Abl membrane translocation with WAVE2, Abi-1, and activated Rac, as well as Abl-mediated tyrosine phosphorylation and WAVE2 activation. By contrast, mutation of tyrosine residue Y150, identified here as the major site of Abl-mediated WAVE2 tyrosine phosphorylation, as well as disruption of WAVE2-Abi-1 binding, impairs induction of WAVE2-driven actin polymerization and its membrane translocation in association with activated Rac. Similarly, WAVE2 tyrosine phosphorylation and induction of membrane actin rearrangement are abrogated in fibroblasts lacking the Abl family kinase. Together, these data reveal that Abi-1-mediated coupling of Abl to WAVE2 promotes Abl-evoked WAVE2 tyrosine phosphorylation required to link WAVE2 with activated Rac and with actin polymerization and remodeling at the cell periphery.

    Proceedings of the National Academy of Sciences of the United States of America 2005;102;4;1098-103

  • Abi enhances Abl-mediated CDC2 phosphorylation and inactivation.

    Lin TY, Huang CH, Chou WG and Juang JL

    Division of Molecular and Genomic Medicine, National Health Research Institutes, Taipei, Taiwan.

    Abelson tyrosine kinase (Abl) is a non-receptor tyrosine kinase which is frequently coupled with adaptor proteins to interact with its substrates for the regulation of cytoskeleton rearrangement, cell growth and apoptosis in response to a variety of biological stimuli. The Abl interactor (Abi) family members were first identified as adaptor proteins of Abl for regulating Abl transforming and kinase activity. In the present study, we used a yeast two-hybrid screen to identify Cdc2 as a novel Abi-binding protein. This finding led us to investigate the role of Abi in linking Abl and Cdc2. These three proteins formed a trimeric complex in Drosophila and mammalian cells. The expression of Abi in cells greatly enhanced the formation of the Abl-Cdc2 complex, suggesting that Abi functions as an adaptor protein facilitating the binding between Abl and Cdc2. We show that Abi promotes Abl-mediated phosphorylation of Cdc2 at tyrosine 15 and inactivation of Cdc2 kinase activity. Furthermore, coexpression of Abl and Abi in Drosophila S2 cells led to suppression of cell growth. These data suggest that Abl signaling may be involved in the downregulation of Cdc2 kinase in cell cycle control.

    Journal of biomedical science 2004;11;6;902-10

  • 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

  • IRSp53/Eps8 complex is important for positive regulation of Rac and cancer cell motility/invasiveness.

    Funato Y, Terabayashi T, Suenaga N, Seiki M, Takenawa T and Miki H

    Division of Cancer Genomics, Biochemistry, and Cancer Cell Research, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.

    IRSp53 has been characterized as an adaptor protein that links Rho-family small GTPases, such as Rac, to reorganization of the actin cytoskeleton. Here, we search for other binding partners for the IRSp53 SH3 domain and identify Eps8 as the major binding protein in fibroblasts and various cancer cell lines. Eps8 has been shown to form a Rac-specific guanine nucleotide exchange factor complex with Abi-1 and Sos-1, which seems essential for ruffling formation induced by oncogenic Ras. We confirm the IRSp53/Eps8 complex formation in vivo and the direct association between Eps8 NH(2)-terminal proline-rich sequence and IRSp53 SH3 domain. This complex synergistically activates Rac by reinforcing the formation of the Eps8/Abi-1/Sos-1 Rac-guanine nucleotide exchange factor complex, which mediates positive regulation of Rac activity. In addition, IRSp53/Eps8 complex formation as determined by fluorescent resonance energy transfer analysis, occurs at the leading edge of motile cells, and the motility and invasiveness of HT1080 fibrosarcoma cells are suppressed by inhibiting complex formation. These findings implicate the importance of the IRSp53/Eps8 complex in Rac activation and metastatic behavior of the malignant tumor cells.

    Cancer research 2004;64;15;5237-44

  • The DNA sequence and comparative analysis of human chromosome 10.

    Deloukas P, Earthrowl ME, Grafham DV, Rubenfield M, French L, Steward CA, Sims SK, Jones MC, Searle S, Scott C, Howe K, Hunt SE, Andrews TD, Gilbert JG, Swarbreck D, Ashurst JL, Taylor A, Battles J, Bird CP, Ainscough R, Almeida JP, Ashwell RI, Ambrose KD, Babbage AK, Bagguley CL, Bailey J, Banerjee R, Bates K, Beasley H, Bray-Allen S, Brown AJ, Brown JY, Burford DC, Burrill W, Burton J, Cahill P, Camire D, Carter NP, Chapman JC, Clark SY, Clarke G, Clee CM, Clegg S, Corby N, Coulson A, Dhami P, Dutta I, Dunn M, Faulkner L, Frankish A, Frankland JA, Garner P, Garnett J, Gribble S, Griffiths C, Grocock R, Gustafson E, Hammond S, Harley JL, Hart E, Heath PD, Ho TP, Hopkins B, Horne J, Howden PJ, Huckle E, Hynds C, Johnson C, Johnson D, Kana A, Kay M, Kimberley AM, Kershaw JK, Kokkinaki M, Laird GK, Lawlor S, Lee HM, Leongamornlert DA, Laird G, Lloyd C, Lloyd DM, Loveland J, Lovell J, McLaren S, McLay KE, McMurray A, Mashreghi-Mohammadi M, Matthews L, Milne S, Nickerson T, Nguyen M, Overton-Larty E, Palmer SA, Pearce AV, Peck AI, Pelan S, Phillimore B, Porter K, Rice CM, Rogosin A, Ross MT, Sarafidou T, Sehra HK, Shownkeen R, Skuce CD, Smith M, Standring L, Sycamore N, Tester J, Thorpe A, Torcasso W, Tracey A, Tromans A, Tsolas J, Wall M, Walsh J, Wang H, Weinstock K, West AP, Willey DL, Whitehead SL, Wilming L, Wray PW, Young L, Chen Y, Lovering RC, Moschonas NK, Siebert R, Fechtel K, Bentley D, Durbin R, Hubbard T, Doucette-Stamm L, Beck S, Smith DR and Rogers J

    The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton CB10 1SA, UK. panos@sanger.ac.uk

    The finished sequence of human chromosome 10 comprises a total of 131,666,441 base pairs. It represents 99.4% of the euchromatic DNA and includes one megabase of heterochromatic sequence within the pericentromeric region of the short and long arm of the chromosome. Sequence annotation revealed 1,357 genes, of which 816 are protein coding, and 430 are pseudogenes. We observed widespread occurrence of overlapping coding genes (either strand) and identified 67 antisense transcripts. Our analysis suggests that both inter- and intrachromosomal segmental duplications have impacted on the gene count on chromosome 10. Multispecies comparative analysis indicated that we can readily annotate the protein-coding genes with current resources. We estimate that over 95% of all coding exons were identified in this study. Assessment of single base changes between the human chromosome 10 and chimpanzee sequence revealed nonsense mutations in only 21 coding genes with respect to the human sequence.

    Nature 2004;429;6990;375-81

  • Abi1 is essential for the formation and activation of a WAVE2 signalling complex.

    Innocenti M, Zucconi A, Disanza A, Frittoli E, Areces LB, Steffen A, Stradal TE, Di Fiore PP, Carlier MF and Scita G

    IFOM Istituto FIRC di Oncologia Molecolare Via Adamello 16, 20134, Milan, Italy.

    WAVE2 belongs to a family of proteins that mediates actin reorganization by relaying signals from Rac to the Arp2/3 complex, resulting in lamellipodia protrusion. WAVE2 displays Arp2/3-dependent actin nucleation activity in vitro, and does not bind directly to Rac. Instead, it forms macromolecular complexes that have been reported to exert both positive and negative modes of regulation. How these complexes are assembled, localized and activated in vivo remains to be established. Here we use tandem mass spectrometry to identify an Abi1-based complex containing WAVE2, Nap1 (Nck-associated protein) and PIR121. Abi1 interacts directly with the WHD domain of WAVE2, increases WAVE2 actin polymerization activity and mediates the assembly of a WAVE2-Abi1-Nap1-PIR121 complex. The WAVE2-Abi1-Nap1-PIR121 complex is as active as the WAVE2-Abi1 sub-complex in stimulating Arp2/3, and after Rac activation it is re-localized to the leading edge of ruffles in vivo. Consistently, inhibition of Abi1 by RNA interference (RNAi) abrogates Rac-dependent lamellipodia protrusion. Thus, Abi1 orchestrates the proper assembly of the WAVE2 complex and mediates its activation at the leading edge in vivo.

    Funded by: Telethon: D.090

    Nature cell biology 2004;6;4;319-27

  • Computational and experimental studies on human misshapen/NIK-related kinase MINK-1.

    Qu K, Lu Y, Lin N, Singh R, Xu X, Payan DG and Xu D

    Rigel, Inc., 1180 Veterans Boulevard, South San Francisco, CA 94080, USA. kqu@rigel.com

    We have studied the structure and function of Human Misshapen/NIK-related kinase (MINK-1) through a combination of computational methods and experimental approaches, including (1) fold recognition and sequence-structure alignment for each structural domain using the threading program PROSPECT, (2) gene expression and protein-protein interaction analysis of yeast homologs of human MINK-1 domains, and (3) yeast two-hybrid screening for proteins that interact with human MINK-1. Our structure prediction dissects MINK-1 into four domains: a conserved N-terminal kinase domain, followed by a coiled-coil region and a proline-rich region, and a C-terminal GCK domain. Gene expression and yeast two-hybrid analysis of yeast homologs of the MINK-1 domains suggest that MINK-1 may be involved in cell-cycle progression and cytoskeletal control. Consistent with these predicted functions, our in-house yeast two-hybrid screen for proteins that interact with human MINK-1 provides strong evidence that the coiled-coil and proline-rich domains of MINK-1 participate in the regulation of cytoskeletal organization, cell-cycle control and apoptosis. A homology model of the MINK-1 kinase domain was used to screen the NCI open compound database in DOCK, and chemical compounds with pharmaceutically acceptable properties were identified. Further medicinal chemistry compound structure optimization and kinase assays are underway.

    Current medicinal chemistry 2004;11;5;569-82

  • The eps8 family of proteins links growth factor stimulation to actin reorganization generating functional redundancy in the Ras/Rac pathway.

    Offenhäuser N, Borgonovo A, Disanza A, Romano P, Ponzanelli I, Iannolo G, Di Fiore PP and Scita G

    The FIRC Institute for Molecular Oncology, 20134 Milan, Italy.

    Sos-1, a guanine nucleotide exchange factor (GEF), eps8 and Abi1, two signaling proteins, and the lipid kinase phosphoinositide 3-kinase (PI3-K), assemble in a multimolecular complex required for Rac activation leading to actin cytoskeletal remodeling. Consistently, eps8 -/- fibroblasts fail to form membrane ruffles in response to growth factor stimulation. Surprisingly, eps8 null mice are healthy, fertile, and display no overt phenotype, suggesting the existence of functional redundancy within this pathway. Here, we describe the identification and characterization of a family of eps8-related proteins, comprising three novel gene products, named eps8L1, eps8L2, and eps8L3. Eps8Ls display collinear topology and 27-42% identity to eps8. Similarly to eps8, eps8Ls interact with Abi1 and Sos-1; however, only eps8L1 and eps8L2 activate the Rac-GEF activity of Sos-1, and bind to actin in vivo. Consistently, eps8L1 and eps8L2, but not eps8L3, localize to PDGF-induced, F-actin-rich ruffles and restore receptor tyrosine kinase (RTK)-mediated actin remodeling when expressed in eps8 -/- fibroblasts. Thus, the eps8Ls define a novel family of proteins responsible for functional redundancy in the RTK-activated signaling pathway leading to actin remodeling. Finally, the patterns of expression of eps8 and eps8L2 in mice are remarkably overlapping, thus providing a likely explanation for the lack of overt phenotype in eps8 null mice.

    Molecular biology of the cell 2004;15;1;91-8

  • Abl interactor 1 promotes tyrosine 296 phosphorylation of mammalian enabled (Mena) by c-Abl kinase.

    Tani K, Sato S, Sukezane T, Kojima H, Hirose H, Hanafusa H and Shishido T

    School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan. tani@ls.toyaku.ac.jp

    Mammalian Enabled (Mena) is a mammalian homologue of Drosophila Enabled (Ena), which genetically interacts with Drosophila Abl tyrosine kinase. The signaling pathway involving c-Abl and Mena (Ena) is not fully understood. To find molecules that participate in the c-Abl/Mena pathway, we searched for Mena-binding proteins using a yeast two-hybrid system. We identified Abl interactor 1 (Abi-1), which is known to interact with c-Abl, as a binding protein for Mena. Binding analysis revealed that the Ena/Vasp homology 1 domain of Mena and the polyproline structure of Abi-1 are necessary for the interaction. The interaction between Mena and Abi-1 was also observed in a mammalian expression system. Importantly, Abi-1 dramatically promoted c-Abl-mediated tyrosine phosphorylation of Mena but not other substrates such as c-Cbl. Mutational analysis demonstrated that the phosphorylation site of Mena is Tyr-296. Our results suggest that Abi-1 regulates c-Abl-mediated phosphorylation of Mena by interacting with both proteins.

    The Journal of biological chemistry 2003;278;24;21685-92

  • Exploring proteomes and analyzing protein processing by mass spectrometric identification of sorted N-terminal peptides.

    Gevaert K, Goethals M, Martens L, Van Damme J, Staes A, Thomas GR and Vandekerckhove J

    Department of Medical Protein Research, Flanders Interuniversity Institute for Biotechnology, Ghent University, A. Baertsoenkaai 3, B-9000 Ghent, Belgium. kris.gevaert@rug.ac.be

    Current non-gel techniques for analyzing proteomes rely heavily on mass spectrometric analysis of enzymatically digested protein mixtures. Prior to analysis, a highly complex peptide mixture is either separated on a multidimensional chromatographic system or it is first reduced in complexity by isolating sets of representative peptides. Recently, we developed a peptide isolation procedure based on diagonal electrophoresis and diagonal chromatography. We call it combined fractional diagonal chromatography (COFRADIC). In previous experiments, we used COFRADIC to identify more than 800 Escherichia coli proteins by tandem mass spectrometric (MS/MS) analysis of isolated methionine-containing peptides. Here, we describe a diagonal method to isolate N-terminal peptides. This reduces the complexity of the peptide sample, because each protein has one N terminus and is thus represented by only one peptide. In this new procedure, free amino groups in proteins are first blocked by acetylation and then digested with trypsin. After reverse-phase (RP) chromatographic fractionation of the generated peptide mixture, internal peptides are blocked using 2,4,6-trinitrobenzenesulfonic acid (TNBS); they display a strong hydrophobic shift and therefore segregate from the unaltered N-terminal peptides during a second identical separation step. N-terminal peptides can thereby be specifically collected for further liquid chromatography (LC)-MS/MS analysis. Omitting the acetylation step results in the isolation of non-lysine-containing N-terminal peptides from in vivo blocked proteins.

    Nature biotechnology 2003;21;5;566-9

  • Induction of colonic epithelial cell apoptosis by p47-dependent oxidants.

    Gu Y, Souza RF, Wu RF, Xu YC and Terada LS

    Department of Internal Medicine, University of Texas Southwestern and the Dallas VAMC, Mail Code 151, 4500 S Lancaster Rd, Dallas, TX 75216, USA.

    Exogenous oxidants appear capable of initiating both proliferative and death signals, but the role of endogenous oxidants in either tumorigenesis or tumor suppression is unclear. We found that expression of the NAD(P)H oxidase adapter p47(phox) was suppressed in human colon carcinoma specimens relative to adjacent normal colon. Overexpression of p47(phox) increased apoptosis in colon cancer cell lines independent of p53 and mismatch-repair competency. p47(phox) was found to interact with the c-Abl adapter Abl interactor-1 (ABI-1), and p47(phox) coprecipitated with both ABI-1 and c-Abl. Ectopic expression of p47(phox) in colon cancer cells increased oxidant production with phosphorylation and activation of nuclear c-Abl and consequent apoptosis. Colonic epithelial p47(phox) may be specifically targeted to a c-Abl-containing complex that serves a physiologic tumor suppressing function.

    Funded by: NHLBI NIH HHS: R01 HL061897, R01 HL067256, R01-HL61897, R01-HL67256

    FEBS letters 2003;540;1-3;195-200

  • Profiling of tyrosine phosphorylation pathways in human cells using mass spectrometry.

    Salomon AR, Ficarro SB, Brill LM, Brinker A, Phung QT, Ericson C, Sauer K, Brock A, Horn DM, Schultz PG and Peters EC

    Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, CA 92121, USA.

    The reversible phosphorylation of tyrosine residues is an important mechanism for modulating biological processes such as cellular signaling, differentiation, and growth, and if deregulated, can result in various types of cancer. Therefore, an understanding of these dynamic cellular processes at the molecular level requires the ability to assess changes in the sites of tyrosine phosphorylation across numerous proteins simultaneously as well as over time. Here we describe a sensitive approach based on multidimensional liquid chromatography/mass spectrometry that enables the rapid identification of numerous sites of tyrosine phosphorylation on a number of different proteins from human whole cell lysates. We used this methodology to follow changes in tyrosine phosphorylation patterns that occur over time during either the activation of human T cells or the inhibition of the oncogenic BCR-ABL fusion product in chronic myelogenous leukemia cells in response to treatment with STI571 (Gleevec). Together, these experiments rapidly identified 64 unique sites of tyrosine phosphorylation on 32 different proteins. Half of these sites have been documented in the literature, validating the merits of our approach, whereas motif analysis suggests that a number of the undocumented sites are also potentially involved in biological pathways. This methodology should enable the rapid generation of new insights into signaling pathways as they occur in states of health and disease.

    Proceedings of the National Academy of Sciences of the United States of America 2003;100;2;443-8

  • Is t(10;11)(p11.2;q23) involving MLL and ABI-1 genes associated with congenital acute monocytic leukemia?

    Morerio C, Rosanda C, Rapella A, Micalizzi C and Panarello C

    Divisione di Ematologia ed Oncologia Pediatrica, Istituto Giannina Gaslini, Largo G. Gaslini 5, 16148, Genova, Italy.

    Congenital, or perinatal, leukemias are rarely observed, but retrospective molecular studies seem to suggest a more frequent onset in prenatal life. Myelocytic types are common, and chromosome band 11q23 rearrangements at the MLL locus are characteristic genetic markers. The fusion of the MLL gene with one of its partners, ABI-1, has recently been described in two infant leukemia patients with monocytic involvement and good clinical outcome. We report a case of congenital monocytic leukemia with the same gene involvement and good response to chemotherapy. The blast metaphases were probed by fluorescence in situ hybridization, and t(10;11)(p11.2;q23) involving MLL and ABI-1 genes was demonstrated with the same breakpoint in ABI-1. The congenital presentation of this case suggests a possible relationship of this genetic event with in utero leukemogenesis.

    Cancer genetics and cytogenetics 2002;139;1;57-9

  • Eps8 in the midst of GTPases.

    Di Fiore PP and Scita G

    Department of Experimental Oncology, European Institute of Oncology, Via Ripamonti, 435, 20141 Milan, Italy. gscita@ieo.it

    Eps8, originally identified as a substrate for the kinase activity of the epidermal growth factor receptor (EGFR), displays a domain organization typical of a signaling molecule that includes a putative N-terminal PTB domain, a central SH3 domain, and a C-terminal "effector region". This latter region directs Eps8 localization within the cell and is sufficient to activate the GTPase, Rac, leading to actin cytoskeletal remodeling. Eps8 binds, through its SH3 domain, to either Abi1 (also called E3b1) or RN-tre. Abi1 scaffolds together Eps8 and Sos1, a dual specificity guanine nucleotide exchange factor for Ras and Rac proteins, thus facilitating the formation of a trimeric complex, in turn required for activation of Rac. On the other hand, RN-tre, a Rab5 GTPase activating protein, by entering in a complex with Eps8, inhibits EGFR internalization. Furthermore, RN-tre competes with Abi1 for binding to Eps8, diverting the latter from its Rac-activating function. Thus, depending on its engagement in different complexes, Eps8 participates to EGFR signaling through Rac and endocytosis through Rab5.

    The international journal of biochemistry & cell biology 2002;34;10;1178-83

  • In search of a function for the E3B1/Abi2/Argbp1/NESH family (Review).

    Ichigotani Y, Fujii K, Hamaguchi M and Matsuda S

    Department of Molecular Pathogenesis, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.

    An E3B1/Abi2/Argbp1/NESH protein family has recently emerged from analysis of the sequence and structural similarities. These are adaptor proteins possessing homeobox homology domain, proline rich region and Src-homology 3 (SH3) domain that interact with Abl-family tyrosine kinases. Some of the members of this family are involved in cytoskeletal reorganization that plays important roles in membrane-ruffling, lamellipodia formation and cell migration. Furthermore, it seems likely that this family may also regulate cancer development through modulation of the oncogenic Abl kinase. The knowledge of this status is helpful in thinking of the regulatory mechanisms to cell metastasis and to malignant transformation of cancer. We discuss how these interesting molecules work and consider their involvement in cancer.

    International journal of molecular medicine 2002;9;6;591-5

  • Forced expression of NESH suppresses motility and metastatic dissemination of malignant cells.

    Ichigotani Y, Yokozaki S, Fukuda Y, Hamaguchi M and Matsuda S

    Department of Molecular Pathogenesis, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.

    To characterize the function of a novel Src homology 3 (SH3) adapter protein termed NESH, we have established transfectants stably expressing NESH. We observed that every clone of NESH transfectants caused a marked reduction in motility, although the clones exhibited no significant differences in intrinsic cell growth compared with the control cells in vitro. The NESH transfectants also exhibited significant reduction in tumor metastatic potential in vivo. We found that NESH expression is frequently lost in invasive cancer cell lines despite its ubiquitous expression in normal tissues. The SH3 domain of NESH seems to interact with p21-activated kinase (PAK), which is involved in regulation of cell motility. Furthermore, a significant decrease in PAK phosphorylation at (402)Thr was found in NESH transfectants. Taken together, these results suggest that NESH inhibits ectopic metastasis of tumor cells as well as cell migration through interaction with intracellular molecules such as PAK that are essential for cell motility.

    Cancer research 2002;62;8;2215-9

  • The SH2/SH3 adaptor Grb4 transduces B-ephrin reverse signals.

    Cowan CA and Henkemeyer M

    Center for Developmental Biology and Kent Waldrep Foundation Center for Basic Research on Nerve Growth and Regeneration, University of Texas Southwestern Medical Center, Dallas 75390-9133, USA.

    Bidirectional signals mediated by membrane-anchored ephrins and Eph receptor tyrosine kinases have important functions in cell-cell recognition events, including those that occur during axon pathfinding and hindbrain segmentation. The reverse signal that is transduced into B-ephrin-expressing cells is thought to involve tyrosine phosphorylation of the signal's short, conserved carboxy-terminal cytoplasmic domain. The Src-homology-2 (SH2) domain proteins that associate with activated tyrosine-phosphorylated B-subclass ephrins have not been identified, nor has a defined cellular response to reverse signals been described. Here we show that the SH2/SH3 domain adaptor protein Grb4 binds to the cytoplasmic domain of B ephrins in a phosphotyrosine-dependent manner. In response to B-ephrin reverse signalling, cells increase FAK catalytic activity, redistribute paxillin, lose focal adhesions, round up, and disassemble F-actin-containing stress fibres. These cellular responses can be blocked in a dominant-negative fashion by expression of the isolated Grb4 SH2 domain. The Grb4 SH3 domains bind a unique set of other proteins that are implicated in cytoskeletal regulation, including the Cbl-associated protein (CAP/ponsin), the Abl-interacting protein-1 (Abi-1), dynamin, PAK1, hnRNPK and axin. These data provide a biochemical pathway whereby cytoskeletal regulators are recruited to Eph-ephrin bidirectional signalling complexes.

    Nature 2001;413;6852;174-9

  • Isolation of hNap1BP which interacts with human Nap1 (NCKAP1) whose expression is down-regulated in Alzheimer's disease.

    Yamamoto A, Suzuki T and Sakaki Y

    Human Genome Center, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan. bun@mpipsykl.mpg.de

    We previously reported the isolation of a novel apoptosis-related gene, human Nap1 (HGMW-approved symbol NCKAP1), the expression of which was strongly down-regulated in sporadic Alzheimer's disease (AD). Human Nap1 proved to be an orthologue of rat Nap1 which binds to the adaptor molecule Nck in signal transduction. In order to further elucidate the function of human Nap1, we performed yeast two-hybrid screening. As a result of screening, we discovered a protein designated hNap1BP (human Nap1 binding protein) which is a member of the tyrosine kinase-binding protein family. In addition, hNap1BP bound to the SH3 domain of c-Abl and Nck. hNap1BP is expressed ubiquitously in various tissues like human Nap1, and intriguingly these genes are co-expressed in hippocampus and cerebral cortex in mouse brain where AD pathological features are strongly evident. Further functional analysis of hNap1BP may clarify its contribution to AD pathology.

    Gene 2001;271;2;159-69

  • The Eps8 protein coordinates EGF receptor signalling through Rac and trafficking through Rab5.

    Lanzetti L, Rybin V, Malabarba MG, Christoforidis S, Scita G, Zerial M and Di Fiore PP

    Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.

    How epidermal growth factor receptor (EGFR) signalling is linked to EGFR trafficking is largely unknown. Signalling and trafficking involve small GTPases of the Rho and Rab families, respectively. But it remains unknown whether the signalling relying on these two classes of GTPases is integrated, and, if it is, what molecular machinery is involved. Here we report that the protein Eps8 connects these signalling pathways. Eps8 is a substrate of the EGFR, which is held in a complex with Sos1 by the adaptor protein E3bl (ref. 2), thereby mediating activation of Rac. Through its src homology-3 domain, Eps8 interacts with RN-tre. We show that RN-tre is a Rab5 GTPase-activating protein, whose activity is regulated by the EGFR. By entering in a complex with Eps8, RN-tre acts on Rab5 and inhibits internalization of the EGFR. Furthermore, RN-tre diverts Eps8 from its Rac-activating function, resulting in the attenuation of Rac signalling. Thus, depending on its state of association with E3b1 or RN-tre, Eps8 participates in both EGFR signalling through Rac, and trafficking through Rab5.

    Nature 2000;408;6810;374-7

  • Human spectrin Src homology 3 domain binding protein 1 regulates macropinocytosis in NIH 3T3 cells.

    Xu J, Ziemnicka D, Merz GS and Kotula L

    Laboratory of Molecular Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA.

    Macropinocytosis is an endocytic process that occurs through non-clathrin coated vesicles larger than 0.2 microm in diameter. Although macropinocytic vesicles are readily visualized in cultured cells by the introduction of fluorescent, water-soluble dyes into the culture medium, protein markers associated with this type of vesicles have not yet been well defined. Here, we report that human spectrin SH3 domain binding protein 1, or Hssh3bp1, associates with macropinosomes in NIH 3T3 fibroblasts. Hssh3bp1 macropinosomes are heterogeneous in morphology and size, do not endocytose transferrin and are resistant to brefeldin A treatment. Cytochalasin D, and wortmannin block endocytosis of fluorescent dyes into the Hssh3bp1 macropinosomes and dramatically affect their morphology. Overexpression of Hssh3bp1-green fluorescent protein abolished fusion of vesicles resulting in a decreased endocytosis of fluorescence dyes, thus suggesting a potential regulatory role of Hssh3bp1 in macropinocytosis. In the macropinosomes of NIH 3T3 cells, Hssh3bp1 associates with a 200-kDa protein that crossreacts with a monoclonal antibody to the erythroid alpha-spectrin SH3 domain. Thus macropinosomes in cells may contain a spectrin-like protein.

    Funded by: NIA NIH HHS: P01 AG04220; NINDS NIH HHS: R29 NS032874, R29 NS032874-05, R29 NS032874-05S1, R29 NS32874

    Journal of cell science 2000;113 Pt 21;3805-14

  • Abl interactor 1 binds to sos and inhibits epidermal growth factor- and v-Abl-induced activation of extracellular signal-regulated kinases.

    Fan PD and Goff SP

    Integrated Program in Cellular, Molecular and Biophysical Studies, Columbia University College of Physicians & Surgeons, New York, New York 10032, USA.

    Recent studies have suggested that members of the Abl interactor (Abi) protein family negatively regulate cell growth and transformation. To date, however, no specific role in these cellular processes has been identified for the Abi family. Here we describe the inhibition by overexpressed Abi-1 of a mitogenic pathway activated by both growth factors and v-Abl. We have identified the guanine nucleotide exchange factors Sos1 and Sos2 as novel binding partners of Abi-1. A domain that is required for interaction with Sos in vivo has been mapped to the amino terminus of Abi-1. Overexpression of Abi-1 inhibits epidermal growth factor (EGF)-induced activation of extracellular signal-regulated kinases (Erks) but does not affect EGF-induced activation of c-Jun N-terminal kinase or Akt. In addition, overexpression of Abi-1 blocks Erk activation induced by v-Abl. In both cases, the maximal inhibitory effect requires an intact amino-terminal Sos-binding domain in Abi-1. Finally, we demonstrate that tyrosine phosphorylation of endogenous Abi-1 in fibroblasts is induced by both v-Abl and serum stimulation, further suggesting a role for Abi-1 in signal transduction initiated by v-Abl and growth factors. Taken together, these findings suggest that overexpressed Abi proteins negatively regulate cell growth and transformation by specifically targeting the Erk pathway.

    Funded by: NCI NIH HHS: P01 CA 75399; NHLBI NIH HHS: MSTP 5T35HL07616, T35 HL007616

    Molecular and cellular biology 2000;20;20;7591-601

  • Localization and phosphorylation of Abl-interactor proteins, Abi-1 and Abi-2, in the developing nervous system.

    Courtney KD, Grove M, Vandongen H, Vandongen A, LaMantia AS and Pendergast AM

    Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, 27710, USA.

    Abl-interactor (Abi) proteins are targets of Abl-family nonreceptor tyrosine kinases and are required for Rac-dependent cytoskeletal reorganization in response to growth factor stimulation. We asked if the expression, phosphorylation, and cellular localization of Abi-1 and Abi-2 supports a role for these proteins in Abl signaling in the developing and adult mouse nervous system. In mid- to late-gestation embryos, abi-2 message is elevated in the central and peripheral nervous systems (CNS and PNS). Abi-1 mRNA is present, but not enhanced, in the CNS, and is not observed in PNS structures. Abi proteins from brain lysates undergo changes in apparent molecular weight and phosphorylation with increasing age. In the postnatal brain, abi-1 and abi-2 are expressed most prominently in cortical layers populated by projection neurons. In cultured neurons, Abi-1 and Abi-2 are concentrated in puncta throughout the cell body and processes. Both Abi and Abl proteins are present in synaptosomes and growth cone particles. Therefore, the Abi adaptors exhibit proper expression patterns and subcellular localization to participate in Abl kinase signaling in the nervous system.

    Funded by: NCI NIH HHS: CA70940

    Molecular and cellular neurosciences 2000;16;3;244-57

  • EPS8 and E3B1 transduce signals from Ras to Rac.

    Scita G, Nordstrom J, Carbone R, Tenca P, Giardina G, Gutkind S, Bjarnegård M, Betsholtz C and Di Fiore PP

    Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.

    The small guanine nucleotide (GTP)-binding protein Rac regulates mitogen-induced cytoskeletal changes and c-Jun amino-terminal kinase (JNK), and its activity is required for Ras-mediated cell transformation. Epistatic analysis placed Rac as a key downstream target in Ras signalling; however, the biochemical mechanism regulating the cross-talk among these small GTP-binding proteins remains to be elucidated. Eps8 (relative molecular mass 97,000) is a substrate of receptors with tyrosine kinase activity which binds, through its SH3 domain, to a protein designated E3b1/Abi-1. Here we show that Eps8 and E3b1/Abi-1 participate in the transduction of signals from Ras to Rac, by regulating Rac-specific guanine nucleotide exchange factor (GEF) activities. We also show that Eps8, E3b1 and Sos-1 form a tri-complex in vivo that exhibits Rac-specific GEF activity in vitro. We propose a model in which Eps8 mediates the transfer of signals between Ras and Rac, by forming a complex with E3b1 and Sos-1.

    Nature 1999;401;6750;290-3

  • ABI-1, a human homolog to mouse Abl-interactor 1, fuses the MLL gene in acute myeloid leukemia with t(10;11)(p11.2;q23).

    Taki T, Shibuya N, Taniwaki M, Hanada R, Morishita K, Bessho F, Yanagisawa M and Hayashi Y

    Department of Pediatrics, Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan.

    Recurrent translocation t(10;11) has been reported to be associated with acute myeloid leukemia (AML). Recently, two types of chimeric transcripts, MLL-AF10 in t(10;11)(p12;q23) and CALM-AF10 in t(10;11)(p13;q14), were isolated. t(10;11) is strongly associated with complex translocations, including invins(10;11) and inv(11)t(10;11), because the direction of transcription of AF10 is telomere to centromere. We analyzed a patient of AML with t(10;11)(p11.2;q23) and identified ABI-1 on chromosome 10p11.2, a human homolog to mouse Abl-interactor 1 (Abi-1), fused with MLL. Whereas the ABI-1 gene bears no homology with the partner genes of MLL previously described, the ABI-1 protein exhibits sequence similarity to protein of homeotic genes, contains several polyproline stretches, and includes a src homology 3 (SH3) domain at the C-terminus that is required for binding to Abl proteins in mouse Abi-1 protein. Recently, e3B1, an eps8 SH3 binding protein 1, was also isolated as a human homolog to mouse Abi-1. Three types of transcripts of ABI-1 gene were expressed in normal peripheral blood. Although e3B1 was considered to be a full-length ABI-1, the MLL-ABI-1 fusion transcript in this patient was formed by an alternatively spliced ABI-1. Others have shown that mouse Abi-1 suppresses v-ABL transforming activity and that e3B1, full-length ABI-1, regulates cell growth. In-frame MLL-ABI-1 fusion transcripts combine the MLL AT-hook motifs and DNA methyltransferase homology region with the homeodomain homologous region, polyproline stretches, and SH3 domain of alternatively spliced transcript of ABI-1. Our results suggest that the ABI-1 gene plays a role in leukemogenesis by translocating to MLL.

    Blood 1998;92;4;1125-30

  • Identification of a candidate human spectrin Src homology 3 domain-binding protein suggests a general mechanism of association of tyrosine kinases with the spectrin-based membrane skeleton.

    Ziemnicka-Kotula D, Xu J, Gu H, Potempska A, Kim KS, Jenkins EC, Trenkner E and Kotula L

    New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA.

    Spectrin is a widely expressed protein with specific isoforms found in erythroid and nonerythroid cells. Spectrin contains an Src homology 3 (SH3) domain of unknown function. A cDNA encoding a candidate spectrin SH3 domain-binding protein was identified by interaction screening of a human brain expression library using the human erythroid spectrin (alphaI) SH3 domain as a bait. Five isoforms of the alphaI SH3 domain-binding protein mRNA were identified in human brain. Mapping of SH3 binding regions revealed the presence of two alphaI SH3 domain binding regions and one Abl-SH3 domain binding region. The gene encoding the candidate spectrin SH3 domain-binding protein has been located to human chromosome 10p11.2 --> p12. The gene belongs to a recently identified family of tyrosine kinase-binding proteins, and one of its isoforms is identical to e3B1, an eps8-binding protein (Biesova, Z., Piccoli, C., and Wong, W. T. (1997)Oncogene 14, 233-241). Overexpression of the green fluorescent protein fusion of the SH3 domain-binding protein in NIH3T3 cells resulted in cytoplasmic punctate fluorescence characteristic of the reticulovesicular system. This fluorescence pattern was similar to that obtained with the anti-human erythroid spectrin alphaI SigmaI/betaI SigmaI antibody in untransfected NIH3T3 cells; in addition, the anti-alphaI SigmaI/betaI SigmaI antibody also stained Golgi apparatus. Immunofluorescence obtained using antibodies against alphaI SigmaI/++betaI SigmaI spectrin and Abl tyrosine kinase but not against alphaII/betaII spectrin colocalized with the overexpressed green fluorescent protein-SH3-binding protein. Based on the conservation of the spectrin SH3 binding site within members of this protein family and published interactions, a general mechanism of interactions of tyrosine kinases with the spectrin-based membrane skeleton is proposed.

    Funded by: NINDS NIH HHS: R29 NS032874, R29 NS032874-05, R29 NS032874-05S1, R29 NS32874

    The Journal of biological chemistry 1998;273;22;13681-92

  • Isolation and characterization of e3B1, an eps8 binding protein that regulates cell growth.

    Biesova Z, Piccoli C and Wong WT

    Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.

    Eps8, a substrate of receptor tyrosine kinases, is an SH3 domain containing protein that plays an important role in mitogenic signaling. To determine the cellular function of eps8, we used the SH3 domain of eps8 to screen a human fibroblast M426 expression library and identified, a full-length cDNA clone of 3.2 kb. We designated this clone e3B1 for eps8 SH3 domain binding protein 1. Northern analysis revealed that expression of e3B1 mRNA was ubiquitous in human tissues. The e3B1 gene encodes a SH3 domain containing protein. We show that anti-e3B1 antibodies detect three cytosolic protein species of 65, 68 and 72 kDa in cell lysate isolated from asynchronously growing NIH3T3 cells. E3B1 binds to the SH3 domain of eps8 and Abl in vitro. We also demonstrated that e3B1 associates with eps8 in vivo. Phosphatase digestion and phosphoamino acid analysis revealed that p65e3B1 is a phosphoserine containing protein and p72e3B1 and p68e3B1 are hyperserine-phosphorylated form of p65e3B1. We further determined that the p65e3B1 was the most abundant in serum-starved NIH/EGFR cells. Time course studies initiated by the addition of epidermal growth factor (EGF) revealed that the p72e3B1 started to accumulate at 4 h, peaked at 8 h and remained high until 24 h. Finally, we demonstrate that NIH/EGFR fibroblasts overexpressing e3B1 grow more slowly relative to matched controls.

    Oncogene 1997;14;2;233-41

  • c-ABL tyrosine kinase activity is regulated by association with a novel SH3-domain-binding protein.

    Zhu J and Shore SK

    Department of Biochemistry, School of Medicine, Temple University, Philadelphia, Pennsylvania 19140, USA.

    The c-ABL tyrosine kinase is activated following either the loss or mutation of its Src homology domain 3 (SH3), resulting in both increased autophosphorylation and phosphorylation of cellular substrates and cellular transformation. This suggests that the SH3 domain negatively regulates c-ABL kinase activity. For several reasons this regulation is thought to involve a cellular protein that binds to the SH3 domain. Hyperexpression of c-ABL results in an activation of its kinase, the kinase activity of purified c-ABL protein in the absence of cellular proteins is independent of either the presence or absence of a SH3 domain, and point mutations and deletions within the SH3 domain are sufficient to activate c-ABL transforming ability. To identify proteins that interact with the c-ABL SH3 domain, we screened a cDNA library by the yeast two-hybrid system, using the c-ABL SH3SH2 domains as bait. We identified a novel protein, AAP1 (ABL-associated protein 1), that associates with these c-ABL domains and fails to bind to the SH3 domain in the activated oncoprotein BCRABL. Kinase experiments demonstrated that in the presence of AAP1, the ability of c-ABL to phosphorylate either glutathione S-transferase-CRK or enolase was inhibited. In contrast, AAP1 had little effect on the phosphorylation of glutathione S-transferase-CRK by the activated ABL oncoproteins v-ABL and BCRABL. We conclude that AAP1 inhibits c-ABL tyrosine kinase activity but has little effect on the tyrosine kinase activities of oncogenic BCRABL or v-ABL protein and propose that AAP1 functions as a trans regulator of c-ABL kinase. Our data also indicate that loss of susceptibility to AAP1 regulation correlates with oncogenicity of the activated forms of c-ABL.

    Funded by: NCI NIH HHS: 5 P30 CA12227

    Molecular and cellular biology 1996;16;12;7054-62

  • Student or worker? International Meeting of Student Nurses (European Group).

    Cardwell C

    Nursing mirror and midwives journal 1976;143;19;38

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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