G2Cdb::Gene report

Gene id
G00000082
Gene symbol
Cacnb1 (MGI)
Species
Mus musculus
Description
calcium channel, voltage-dependent, beta 1 subunit
Orthologue
G00001331 (Homo sapiens)

Databases (9)

Curated Gene
OTTMUSG00000002912 (Vega mouse gene)
Gene
ENSMUSG00000020882 (Ensembl mouse gene)
12295 (Entrez Gene)
422 (G2Cdb plasticity & disease)
Gene Expression
MGI:102522 (Allen Brain Atlas)
g04348 (BGEM)
Literature
114207 (OMIM)
Marker Symbol
MGI:102522 (MGI)
Protein Sequence
Q8R3Z5 (UniProt)

Synonyms (2)

  • Cchb1
  • Cchlb1

Literature (30)

Pubmed - other

  • A high-resolution anatomical atlas of the transcriptome in the mouse embryo.

    Diez-Roux G, Banfi S, Sultan M, Geffers L, Anand S, Rozado D, Magen A, Canidio E, Pagani M, Peluso I, Lin-Marq N, Koch M, Bilio M, Cantiello I, Verde R, De Masi C, Bianchi SA, Cicchini J, Perroud E, Mehmeti S, Dagand E, Schrinner S, Nürnberger A, Schmidt K, Metz K, Zwingmann C, Brieske N, Springer C, Hernandez AM, Herzog S, Grabbe F, Sieverding C, Fischer B, Schrader K, Brockmeyer M, Dettmer S, Helbig C, Alunni V, Battaini MA, Mura C, Henrichsen CN, Garcia-Lopez R, Echevarria D, Puelles E, Garcia-Calero E, Kruse S, Uhr M, Kauck C, Feng G, Milyaev N, Ong CK, Kumar L, Lam M, Semple CA, Gyenesei A, Mundlos S, Radelof U, Lehrach H, Sarmientos P, Reymond A, Davidson DR, Dollé P, Antonarakis SE, Yaspo ML, Martinez S, Baldock RA, Eichele G and Ballabio A

    Telethon Institute of Genetics and Medicine, Naples, Italy.

    Ascertaining when and where genes are expressed is of crucial importance to understanding or predicting the physiological role of genes and proteins and how they interact to form the complex networks that underlie organ development and function. It is, therefore, crucial to determine on a genome-wide level, the spatio-temporal gene expression profiles at cellular resolution. This information is provided by colorimetric RNA in situ hybridization that can elucidate expression of genes in their native context and does so at cellular resolution. We generated what is to our knowledge the first genome-wide transcriptome atlas by RNA in situ hybridization of an entire mammalian organism, the developing mouse at embryonic day 14.5. This digital transcriptome atlas, the Eurexpress atlas (http://www.eurexpress.org), consists of a searchable database of annotated images that can be interactively viewed. We generated anatomy-based expression profiles for over 18,000 coding genes and over 400 microRNAs. We identified 1,002 tissue-specific genes that are a source of novel tissue-specific markers for 37 different anatomical structures. The quality and the resolution of the data revealed novel molecular domains for several developing structures, such as the telencephalon, a novel organization for the hypothalamus, and insight on the Wnt network involved in renal epithelial differentiation during kidney development. The digital transcriptome atlas is a powerful resource to determine co-expression of genes, to identify cell populations and lineages, and to identify functional associations between genes relevant to development and disease.

    Funded by: Medical Research Council: MC_U127527203; Telethon: TGM11S03

    PLoS biology 2011;9;1;e1000582

  • Voltage-activated calcium channel expression profiles in mouse brain and cultured hippocampal neurons.

    Schlick B, Flucher BE and Obermair GJ

    Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck, Austria.

    The importance and diversity of calcium signaling in the brain is mirrored by the expression of a multitude of voltage-activated calcium channel (Ca(V)) isoforms. Whereas the overall distributions of alpha(1) subunits are well established, the expression patterns of distinct channel isoforms in specific brain regions and neurons, as well as those of the auxiliary beta and alpha(2)delta subunits are still incompletely characterized. Further it is unknown whether neuronal differentiation and activity induce changes of Ca(V) subunit composition. Here we combined absolute and relative quantitative TaqMan reverse transcription PCR (RT-PCR) to analyze mRNA expression of all high voltage-activated Ca(V) alpha(1) subunits and all beta and alpha(2)delta subunits. This allowed for the first time the direct comparison of complete Ca(V) expression profiles of mouse cortex, hippocampus, cerebellum, and cultured hippocampal neurons. All brain regions expressed characteristic profiles of the full set of isoforms, except Ca(V)1.1 and Ca(V)1.4. In cortex development was accompanied by a general down regulation of alpha(1) and alpha(2)delta subunits and a shift from beta(1)/beta(3) to beta(2)/beta(4). The most abundant Ca(V) isoforms in cerebellum were Ca(V)2.1, beta(4), and alpha(2)delta-2, and in hippocampus Ca(V)2.3, beta(2), and alpha(2)delta-1. Interestingly, cultured hippocampal neurons also expressed the same Ca(V) complement as adult hippocampus. During differentiation specific Ca(V) isoforms experienced up- or down-regulation; however blocking electrical activity did not affect Ca(V) expression patterns. Correlation analysis of alpha(1), beta and alpha(2)delta subunit expression throughout all examined preparations revealed a strong preference of Ca(V)2.1 for beta(4) and alpha(2)delta-2 and vice versa, whereas the other alpha(1) isoforms were non-selectively expressed together with each of the other beta and alpha(2)delta isoforms. Together our results revealed a remarkably stable overall Ca(2+) channel complement as well as tissue specific differences in expression levels. Developmental changes are likely determined by an intrinsic program and not regulated by changes in neuronal activity.

    Funded by: Austrian Science Fund FWF: P 17806, P 17807, P 20059

    Neuroscience 2010;167;3;786-98

  • Reciprocal interactions regulate targeting of calcium channel beta subunits and membrane expression of alpha1 subunits in cultured hippocampal neurons.

    Obermair GJ, Schlick B, Di Biase V, Subramanyam P, Gebhart M, Baumgartner S and Flucher BE

    Department of Physiology and Medical Physics, Innsbruck Medical University, Austria. Gerald.Obermair@i-med.ac.at

    Auxiliary beta subunits modulate current properties and mediate the functional membrane expression of voltage-gated Ca(2+) channels in heterologous cells. In brain, all four beta isoforms are widely expressed, yet little is known about their specific roles in neuronal functions. Here, we investigated the expression and targeting properties of beta subunits and their role in membrane expression of Ca(V)1.2 alpha(1) subunits in cultured hippocampal neurons. Quantitative reverse transcription-PCR showed equal expression, and immunofluorescence showed a similar distribution of all endogenous beta subunits throughout dendrites and axons. High resolution microscopy of hippocampal neurons transfected with six different V5 epitope-tagged beta subunits demonstrated that all beta subunits were able to accumulate in synaptic terminals and to colocalize with postsynaptic Ca(V)1.2, thus indicating a great promiscuity in alpha(1)-beta interactions. In contrast, restricted axonal targeting of beta(1) and weak colocalization of beta(4b) with Ca(V)1.2 indicated isoform-specific differences in local channel complex formation. Membrane expression of external hemagglutinin epitope-tagged Ca(V)1.2 was strongly enhanced by all beta subunits in an isoform-specific manner. Conversely, mutating the alpha-interaction domain of Ca(V)1.2 (W440A) abolished membrane expression and targeting into dendritic spines. This demonstrates that in neurons the interaction of a beta subunit with the alpha-interaction domain is absolutely essential for membrane expression of alpha(1) subunits, as well as for the subcellular localization of beta subunits, which by themselves possess little or no targeting properties.

    Funded by: Austrian Science Fund FWF: P 17806, P 17807, P 20059, W 1101

    The Journal of biological chemistry 2010;285;8;5776-91

  • Diversity and developmental expression of L-type calcium channel beta2 proteins and their influence on calcium current in murine heart.

    Link S, Meissner M, Held B, Beck A, Weissgerber P, Freichel M and Flockerzi V

    Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany. sabine.link@uks.eu

    By now, little is known on L-type calcium channel (LTCC) subunits expressed in mouse heart. We show that CaVbeta2 proteins are the major CaVbeta components of the LTCC in embryonic and adult mouse heart, but that in embryonic heart CaVbeta3 proteins are also detectable. At least two CaVbeta2 variants of approximately 68 and approximately 72 kDa are expressed. To identify the underlying CaVbeta2 variants, cDNA libraries were constructed from poly(A)(+) RNA isolated from hearts of 7-day-old and adult mice. Screening identified 60 independent CaVbeta2 cDNA clones coding for four types of CaVbeta2 proteins only differing in their 5' sequences. CaVbeta2-N1, -N4, and -N5 but not -N3 were identified in isolated cardiomyocytes by RT-PCR and were sufficient to reconstitute the CaVbeta2 protein pattern in vitro. Significant L-type Ca(2+) currents (I(Ca)) were recorded in HEK293 cells after co-expression of CaV1.2 and CaVbeta2. Current kinetics were determined by the type of CaVbeta2 protein, with the approximately 72-kDa CaVbeta2a-N1 shifting the activation of I(Ca) significantly to depolarizing potentials compared with the other CaVbeta2 variants. Inactivation of I(Ca) was accelerated by CaVbeta2a-N1 and -N4, which also lead to slower activation compared with CaVbeta2a-N3 and -N5. In summary, this study reveals the molecular LTCC composition in mouse heart and indicates that expression of various CaVbeta2 proteins may be used to adapt the properties of LTCCs to changing myocardial requirements during development and that CaVbeta2a-N1-induced changes of I(Ca) kinetics might be essential in embryonic heart.

    The Journal of biological chemistry 2009;284;44;30129-37

  • NCAM induces CaMKIIalpha-mediated RPTPalpha phosphorylation to enhance its catalytic activity and neurite outgrowth.

    Bodrikov V, Sytnyk V, Leshchyns'ka I, den Hertog J and Schachner M

    Zentrum für Molekulare Neurobiologie, Universität Hamburg, 20246 Hamburg, Germany.

    Receptor protein tyrosine phosphatase alpha (RPTPalpha) phosphatase activity is required for intracellular signaling cascades that are activated in motile cells and growing neurites. Little is known, however, about mechanisms that coordinate RPTPalpha activity with cell behavior. We show that clustering of neural cell adhesion molecule (NCAM) at the cell surface is coupled to an increase in serine phosphorylation and phosphatase activity of RPTPalpha. NCAM associates with T- and L-type voltage-dependent Ca(2+) channels, and NCAM clustering at the cell surface results in Ca(2+) influx via these channels and activation of NCAM-associated calmodulin-dependent protein kinase IIalpha (CaMKIIalpha). Clustering of NCAM promotes its redistribution to lipid rafts and the formation of a NCAM-RPTPalpha-CaMKIIalpha complex, resulting in serine phosphorylation of RPTPalpha by CaMKIIalpha. Overexpression of RPTPalpha with mutated Ser180 and Ser204 interferes with NCAM-induced neurite outgrowth, which indicates that neurite extension depends on NCAM-induced up-regulation of RPTPalpha activity. Thus, we reveal a novel function for a cell adhesion molecule in coordination of cell behavior with intracellular phosphatase activity.

    The Journal of cell biology 2008;182;6;1185-200

  • Absence of regulation of the T-type calcium current by Cav1.1, beta1a and gamma1 dihydropyridine receptor subunits in skeletal muscle cells.

    Strube C

    UMR CNRS 5123, UCB-Lyon1, 69622, Villeurbanne, Cedex, France. caroline.strube@univmed.fr

    The subunit structure of low voltage activated T-type Ca2+ channels is still unknown. Co-expression of dihydropyridine receptor (DHPR) auxiliary subunits with T-type alpha1 subunits in heterologous systems has produced conflicting results. In developing foetal skeletal muscle fibres which abundantly express DHPR subunits, Cav3.2 (alpha1H) subunits are believed to underlie T-type calcium currents which disappear 2 to 3 weeks after birth. Therefore, a possible regulation of foetal skeletal muscle T-type Ca2+ channels by DHPR subunits was investigated in freshly isolated foetal skeletal muscle using knockout mice, which provide a powerful tool to address this question. The possible involvement of alpha1S (Cav1.1), beta1 and gamma1 DHPR subunits was tested using dysgenic (alpha1S-null), beta1a and gamma1 knockout mice. The results show that the absence of alpha1S, beta1 or gamma1 DHPR subunits does not significantly affect the electrophysiological properties of T-type Ca2+ currents in skeletal muscle, suggesting that (1) native Cav3.2 is not regulated by beta1 or gamma1 DHPR subunits; (2) T-type and L-type currents have distinct and not interchangeable roles.

    Pflugers Archiv : European journal of physiology 2008;455;5;921-7

  • Large-scale analysis of ion channel gene expression in the mouse heart during perinatal development.

    Harrell MD, Harbi S, Hoffman JF, Zavadil J and Coetzee WA

    Pediatric Cardiology, New York University School of Medicine, New York, New York 10016, USA.

    The immature and mature heart differ from each other in terms of excitability, action potential properties, contractility, and relaxation. This includes upregulation of repolarizing K(+) currents, an enhanced inward rectifier K(+) (Kir) current, and changes in Ca(2+), Na(+), and Cl(-) currents. At the molecular level, the developmental regulation of ion channels is scantily described. Using a large-scale real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assay, we performed a comprehensive analysis of ion channel transcript expression during perinatal development in the embryonic (embryonic day 17.5), neonatal (postnatal days 1-2), and adult Swiss-Webster mouse hearts. These data are compared with publicly available microarray data sets (Cardiogenomics project). Developmental mRNA expression for several transcripts was consistent with the published literature. For example, transcripts such as Kir2.1, Kir3.1, Nav1.5, Cav1.2, etc. were upregulated after birth, whereas others [e.g., Ca(2+)-activated K(+) (KCa)2.3 and minK] were downregulated. Cl(-) channel transcripts were expressed at higher levels in immature heart, particularly those that are activated by intracellular Ca(2+). Defining alterations in the ion channel transcriptome during perinatal development will lead to a much improved understanding of the electrophysiological alterations occurring in the heart after birth. Our study may have important repercussions in understanding the mechanisms and consequences of electrophysiological alterations in infants and may pave the way for better understanding of clinically relevant events such as congenital abnormalities, cardiomyopathies, heart failure, arrhythmias, cardiac drug therapy, and the sudden infant death syndrome.

    Funded by: NHLBI NIH HHS: 1 R01 HL-64838

    Physiological genomics 2007;28;3;273-83

  • Qualitative and quantitative analyses of protein phosphorylation in naive and stimulated mouse synaptosomal preparations.

    Munton RP, Tweedie-Cullen R, Livingstone-Zatchej M, Weinandy F, Waidelich M, Longo D, Gehrig P, Potthast F, Rutishauser D, Gerrits B, Panse C, Schlapbach R and Mansuy IM

    Brain Research Institute, Medical Faculty of the University of Zürich, Switzerland.

    Activity-dependent protein phosphorylation is a highly dynamic yet tightly regulated process essential for cellular signaling. Although recognized as critical for neuronal functions, the extent and stoichiometry of phosphorylation in brain cells remain undetermined. In this study, we resolved activity-dependent changes in phosphorylation stoichiometry at specific sites in distinct subcellular compartments of brain cells. Following highly sensitive phosphopeptide enrichment using immobilized metal affinity chromatography and mass spectrometry, we isolated and identified 974 unique phosphorylation sites on 499 proteins, many of which are novel. To further explore the significance of specific phosphorylation sites, we used isobaric peptide labels and determined the absolute quantity of both phosphorylated and non-phosphorylated peptides of candidate phosphoproteins and estimated phosphorylation stoichiometry. The analyses of phosphorylation dynamics using differentially stimulated synaptic terminal preparations revealed activity-dependent changes in phosphorylation stoichiometry of target proteins. Using this method, we were able to differentiate between distinct isoforms of Ca2+/calmodulin-dependent protein kinase (CaMKII) and identify a novel activity-regulated phosphorylation site on the glutamate receptor subunit GluR1. Together these data illustrate that mass spectrometry-based methods can be used to determine activity-dependent changes in phosphorylation stoichiometry on candidate phosphopeptides following large scale phosphoproteome analysis of brain tissue.

    Molecular & cellular proteomics : MCP 2007;6;2;283-93

  • The light peak of the electroretinogram is dependent on voltage-gated calcium channels and antagonized by bestrophin (best-1).

    Marmorstein LY, Wu J, McLaughlin P, Yocom J, Karl MO, Neussert R, Wimmers S, Stanton JB, Gregg RG, Strauss O, Peachey NS and Marmorstein AD

    Department of Ophthalmology and Vision Science, University of Arizona, Tucson 85711, USA.

    Mutations in VMD2, encoding bestrophin (best-1), cause Best vitelliform macular dystrophy (BMD), adult-onset vitelliform macular dystrophy (AVMD), and autosomal dominant vitreoretinochoroidopathy (ADVIRC). BMD is distinguished from AVMD by a diminished electrooculogram light peak (LP) in the absence of changes in the flash electroretinogram. Although the LP is thought to be generated by best-1, we find enhanced LP luminance responsiveness with normal amplitude in Vmd2-/- mice and no differences in cellular Cl- currents in comparison to Vmd2+/+ littermates. The putative Ca2+ sensitivity of best-1, and our recent observation that best-1 alters the kinetics of voltage-dependent Ca2+ channels (VDCC), led us to examine the role of VDCCs in the LP. Nimodipine diminished the LP, leading us to survey VDCC beta-subunit mutant mice. Lethargic mice, which harbor a loss of function mutation in the beta4 subunit of VDCCs, exhibited a significant shift in LP luminance response, establishing a role for Ca2+ in LP generation. When stimulated with ATP, which increases [Ca++]I, retinal pigment epithelial cells derived from Vmd2-/- mice exhibited a fivefold greater response than Vmd2+/+ littermates, indicating that best-1 can suppress the rise in [Ca2+]I associated with the LP. We conclude that VDCCs regulated by a beta4 subunit are required to generate the LP and that best-1 antagonizes the LP luminance response potentially via its ability to modulate VDCC function. Furthermore, we suggest that the loss of vision associated with BMD is not caused by the same pathologic process as the diminished LP, but rather is caused by as yet unidentified effects of best-1 on other cellular processes.

    Funded by: NEI NIH HHS: EY12354, EY13160, EY13847, EY14465, EY14898, EY15638, R01 EY012354, R01 EY012354-03, R01 EY013160, R01 EY013847, R01 EY014465, R01 EY014465-03, R03 EY014898, R24 EY015638, R56 EY013160

    The Journal of general physiology 2006;127;5;577-89

  • Comprehensive identification of phosphorylation sites in postsynaptic density preparations.

    Trinidad JC, Specht CG, Thalhammer A, Schoepfer R and Burlingame AL

    Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, USA.

    In the mammalian central nervous system, the structure known as the postsynaptic density (PSD) is a dense complex of proteins whose function is to detect and respond to neurotransmitter released from presynaptic axon terminals. Regulation of protein phosphorylation in this molecular machinery is critical to the activity of its components, which include neurotransmitter receptors, kinases/phosphatases, scaffolding molecules, and proteins regulating cytoskeletal structure. To characterize the phosphorylation state of proteins in PSD samples, we combined strong cation exchange (SCX) chromatography with IMAC. Initially, tryptic peptides were separated by cation exchange and analyzed by reverse phase chromatography coupled to tandem mass spectrometry, which led to the identification of phosphopeptides in most SCX fractions. Because each of these individual fractions was too complex to characterize completely in single LC-MS/MS runs, we enriched for phosphopeptides by performing IMAC on each SCX fraction, yielding at least a 3-fold increase in identified phosphopeptides relative to either approach alone (SCX or IMAC). This enabled us to identify at least one site of phosphorylation on 23% (287 of 1,264) of all proteins found to be present in the postsynaptic density preparation. In total, we identified 998 unique phosphorylated peptides, mapping to 723 unique sites of phosphorylation. At least one exact site of phosphorylation was determined on 62% (621 of 998) of all phosphopeptides, and approximately 80% of identified phosphorylation sites are novel.

    Funded by: NCRR NIH HHS: RR14606; Wellcome Trust

    Molecular & cellular proteomics : MCP 2006;5;5;914-22

  • BGEM: an in situ hybridization database of gene expression in the embryonic and adult mouse nervous system.

    Magdaleno S, Jensen P, Brumwell CL, Seal A, Lehman K, Asbury A, Cheung T, Cornelius T, Batten DM, Eden C, Norland SM, Rice DS, Dosooye N, Shakya S, Mehta P and Curran T

    Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States.

    Funded by: NINDS NIH HHS: 5R37NS036558, N01-NS-0-2331, R37 NS036558

    PLoS biology 2006;4;4;e86

  • Organization of calcium channel beta1a subunits in triad junctions in skeletal muscle.

    Leuranguer V, Papadopoulos S and Beam KG

    Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523-1617, USA.

    In skeletal muscle, dihydropyridine receptors (DHPRs) in the plasma membrane interact with the type 1 ryanodine receptor (RyR1) at junctions with the sarcoplasmic reticulum. This interaction organizes junctional DHPRs into groups of four termed tetrads. In addition to the principle alpha1S subunit, the beta1a subunit of the DHPR is also important for the interaction with RyR1. To probe this interaction, we measured fluorescence resonance energy transfer (FRET) of beta1a subunits labeled with cyan fluorescent protein (CFP) and/or yellow fluorescent protein (YFP). Expressed in dysgenic (alpha1S-null) myotubes, YFP-beta1a-CFP and CFP-beta1a-YFP were diffusely distributed in the cytoplasm and highly mobile as indicated by fluorescence recovery after photobleaching. Thus, beta1a does not appear to bind to other cellular proteins in the absence of alpha1S. FRET efficiencies for these cytoplasmic beta1a subunits were approximately 6-7%, consistent with the idea that <10 nm separates the N and C termini. After coexpression with unlabeled alpha1S (in dysgenic or beta1-null myotubes), both constructs produced discrete fluorescent puncta, which correspond to assembled DHPRs in junctions and that did not recover after photobleaching. In beta1-null myotubes, FRET efficiencies of doubly labeled beta1a in puncta were similar to those of the same constructs diffusely distributed in the cytoplasm and appeared to arise intramolecularly, since no FRET was measured when mixtures of singly labeled beta1a (CFP or YFP at the N or C terminus) were expressed in beta1-null myotubes. Thus, DHPRs in tetrads may be arranged such that the N and C termini of adjacent beta1a subunits are located >10 nm from one another.

    The Journal of biological chemistry 2006;281;6;3521-7

  • Interaction between the dihydropyridine receptor Ca2+ channel beta-subunit and ryanodine receptor type 1 strengthens excitation-contraction coupling.

    Cheng W, Altafaj X, Ronjat M and Coronado R

    Department of Physiology, University of Wisconsin School of Medicine, Madison, WI 53706, USA.

    Previous studies have shown that the skeletal dihydropyridine receptor (DHPR) pore subunit Ca(V)1.1 (alpha1S) physically interacts with ryanodine receptor type 1 (RyR1), and a molecular signal is transmitted from alpha1S to RyR1 to trigger excitation-contraction (EC) coupling. We show that the beta-subunit of the skeletal DHPR also binds RyR1 and participates in this signaling process. A novel binding site for the DHPR beta1a-subunit was mapped to the M(3201) to W(3661) region of RyR1. In vitro binding experiments showed that the strength of the interaction is controlled by K(3495)KKRR_ _R(3502), a cluster of positively charged residues. Phenotypic expression of skeletal-type EC coupling by RyR1 with mutations in the K(3495)KKRR_ _R(3502) cluster was evaluated in dyspedic myotubes. The results indicated that charge neutralization or deletion severely depressed the magnitude of RyR1-mediated Ca(2+) transients coupled to voltage-dependent activation of the DHPR. Meantime the Ca(2+) content of the sarcoplasmic reticulum was not affected, and the amplitude and activation kinetics of the DHPR Ca(2+) currents were slightly affected. The data show that the DHPR beta-subunit, like alpha1S, interacts directly with RyR1 and is critical for the generation of high-speed Ca(2+) signals coupled to membrane depolarization. These findings indicate that EC coupling in skeletal muscle involves the interplay of at least two subunits of the DHPR, namely alpha1S and beta1a, interacting with possibly different domains of RyR1.

    Funded by: NIAMS NIH HHS: AR46448, R01 AR046448

    Proceedings of the National Academy of Sciences of the United States of America 2005;102;52;19225-30

  • Voltage-gated calcium channels in developing GnRH-1 neuronal system in the mouse.

    Toba Y, Pakiam JG and Wray S

    Cellular and Developmental Neurobiology Section, NINDS, NIH, Bethesda, MD 20892, USA.

    Migration of gonadotropin-releasing hormone-1 (GnRH-1) neurons from the nasal placode into the central nervous system occurs in all vertebrates. This study characterizes the expression of L- and N-type voltage-gated calcium channels (VGCCs) in migrating GnRH-1 neurons in mice. Class C (L-type) and class B (N-type) VGCGs were detected in GnRH-1 cells and cells in the olfactory and vomeronasal epithelium during prenatal development. This expression pattern was mimicked in a nasal explant model known to retain many characteristics of GnRH-1 development in vivo. Using this in vitro system, perturbation studies were performed to elucidate the role of VGCCs in GnRH-1 neuronal development. This report shows that olfactory axon outgrowth and GnRH-1 neuronal migration are attenuated when nasal explants are grown in calcium-free media, and that this effect is temporally restricted to an early developmental period. Blockade of either the L- or the N-type channel did not alter GnRH-1 cell number or overall olfactory axon outgrowth. However, blockade of N-type channels altered the distribution of GnRH-1 neurons in the periphery of the nasal explants. In these explants, more GnRH-1 neurons were located proximal to, and fewer GnRH-1 neurons distal to, the main tissue mass, suggesting a general decrease in the rate of GnRH-1 neuronal migration. These results indicate that extracellular calcium is required for initiating GnRH-1 neuronal migration and that these events are partially dependent on N-type VGCC signals.

    The European journal of neuroscience 2005;22;1;79-92

  • Wnk1 kinase deficiency lowers blood pressure in mice: a gene-trap screen to identify potential targets for therapeutic intervention.

    Zambrowicz BP, Abuin A, Ramirez-Solis R, Richter LJ, Piggott J, BeltrandelRio H, Buxton EC, Edwards J, Finch RA, Friddle CJ, Gupta A, Hansen G, Hu Y, Huang W, Jaing C, Key BW, Kipp P, Kohlhauff B, Ma ZQ, Markesich D, Payne R, Potter DG, Qian N, Shaw J, Schrick J, Shi ZZ, Sparks MJ, Van Sligtenhorst I, Vogel P, Walke W, Xu N, Zhu Q, Person C and Sands AT

    Lexicon Genetics, 8800 Technology Forest Place, The Woodlands, TX 77381, USA. brian@lexgen.com

    The availability of both the mouse and human genome sequences allows for the systematic discovery of human gene function through the use of the mouse as a model system. To accelerate the genetic determination of gene function, we have developed a sequence-tagged gene-trap library of >270,000 mouse embryonic stem cell clones representing mutations in approximately 60% of mammalian genes. Through the generation and phenotypic analysis of knockout mice from this resource, we are undertaking a functional screen to identify genes regulating physiological parameters such as blood pressure. As part of this screen, mice deficient for the Wnk1 kinase gene were generated and analyzed. Genetic studies in humans have shown that large intronic deletions in WNK1 lead to its overexpression and are responsible for pseudohypoaldosteronism type II, an autosomal dominant disorder characterized by hypertension, increased renal salt reabsorption, and impaired K+ and H+ excretion. Consistent with the human genetic studies, Wnk1 heterozygous mice displayed a significant decrease in blood pressure. Mice homozygous for the Wnk1 mutation died during embryonic development before day 13 of gestation. These results demonstrate that Wnk1 is a regulator of blood pressure critical for development and illustrate the utility of a functional screen driven by a sequence-based mutagenesis approach.

    Proceedings of the National Academy of Sciences of the United States of America 2003;100;24;14109-14

  • Mapping blood pressure loci in (A/J x B6)F2 mice.

    Woo DD and Kurtz I

    David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA. dwoo@mednet.ucla.edu

    Although the genetics of rare, monogenic, forms of human hypertension are fairly well defined, the genetics of the common polygenic form of human essential hypertension is only emerging. With the ability to control environmental variables, animal models have provided valuable tools with which to study blood pressure (BP) homeostasis. We have now studied BP genetics in a model consisting of 1,521 F2 mice from a series of (A/J x B6) intercrosses kept under standardized conditions. Using whole genome quantitative trait loci (QTL) mapping, we have identified four novel significant BP loci. These included Abbp1 on mouse chromosome MMU1 [maximum LOD score (MLS) at approximately 35 cM = 6.8], Abbp2 on MMU4 (MLS at approximately 25 cM = 9.8), Abbp3 on MMU7 (MLS at approximately 25 cM = 5.4), and Abbp4 on MMU11 (MLS at approximately 58 cM = 6.3). Compared with A/J homozygotes, homozygosity for the B6 alleles of Abbp1, Abbp2, or Abbp4 is independently associated with a 7-12 mmHg increase in BP. In contrast Abbp3 interacts epistatically with a locus on MMU17 (near D17Mit180) to modulate BPs in female (A/J x B6)F2 mice. Interestingly, Abbp4 on MMU11 is homologous to a major confirmed BP locus, BP1, on rat chromosome 10 and to a major confirmed BP locus, HYT1, on human chromosome 17. Defining the molecular differences between the A/J and the B6 alleles at these novel loci with major influences on the BP phenotype will contribute to our understanding of the complex genetics of BP control.

    Funded by: NIDDK NIH HHS: DK-58563, DK-60514, DK-63125

    Physiological genomics 2003;15;3;236-42

  • BayGenomics: a resource of insertional mutations in mouse embryonic stem cells.

    Stryke D, Kawamoto M, Huang CC, Johns SJ, King LA, Harper CA, Meng EC, Lee RE, Yee A, L'Italien L, Chuang PT, Young SG, Skarnes WC, Babbitt PC and Ferrin TE

    Department of Pharmaceutical Chemistry, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA.

    The BayGenomics gene-trap resource (http://baygenomics.ucsf.edu) provides researchers with access to thousands of mouse embryonic stem (ES) cell lines harboring characterized insertional mutations in both known and novel genes. Each cell line contains an insertional mutation in a specific gene. The identity of the gene that has been interrupted can be determined from a DNA sequence tag. Approximately 75% of our cell lines contain insertional mutations in known mouse genes or genes that share strong sequence similarities with genes that have been identified in other organisms. These cell lines readily transmit the mutation to the germline of mice and many mutant lines of mice have already been generated from this resource. BayGenomics provides facile access to our entire database, including sequence tags for each mutant ES cell line, through the World Wide Web. Investigators can browse our resource, search for specific entries, download any portion of our database and BLAST sequences of interest against our entire set of cell line sequence tags. They can then obtain the mutant ES cell line for the purpose of generating knockout mice.

    Funded by: NCRR NIH HHS: P41 RR001081, P41 RR01081; NHLBI NIH HHS: U01 HL066621, U01 HL66621

    Nucleic acids research 2003;31;1;278-81

  • Structures of the murine genes for the beta1- and beta4-subunits of the voltage-dependent calcium channel.

    Murakami M, Miyoshi I, Suzuki T, Sasano H and Iijima T

    Department of Pharmacology, Akita University School of Medicine, 1-1-1, Hondou, Akita 010-8543, Japan. manabumurakami@excite.co.jp

    The structures of the genomic DNA of the murine beta1- and beta4-subunits of the voltage-dependent calcium channel were mapped by comparing genomic and cDNA sequences. The gene structure analysis revealed that the murine beta1 gene consists of 15 translated exons spread over 19 kb of the genome, whereas the beta4 gene consists of 13 translated exons spread over 124 kb of the genome. Alternative spliced transcripts of the beta1 gene were also characterized. Although the total lengths differ, these subunits have exon-intron organization similar to the murine beta2- and beta3-, and human beta4-subunits, showing the highly conserved gene structure of this family. Furthermore, mRNA of these beta-subunits is strongly expressed in dorsal root ganglion neurons, which have many voltage-dependent calcium channels.

    Journal of molecular neuroscience : MN 2003;21;1;13-21

  • Mice with cardiac-specific sequestration of the beta-subunit of the L-type calcium channel.

    Serikov V, Bodi I, Koch SE, Muth JN, Mikala G, Martinov SG, Haase H and Schwartz A

    Department of Surgery, Institute of Molecular Pharmacology and Biophysics, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0828, USA.

    The beta subunit of the L-type voltage-dependent calcium channel modifies the properties of the channel complex by both allosteric modulation of the alpha1 subunit function and by chaperoning the translocation of the alpha1 subunit to the plasma membrane. The goal of this study was to investigate the functional effect of changing the in vivo stoichiometry between the alpha1 and beta subunits by creating a dominant negative expression system in a transgenic mouse model. The high affinity beta subunit-binding domain of the alpha1 subunit was overexpressed in a cardiac-specific manner to act as a beta subunit trap. We found that the predominant beta isoform was located primarily in the membrane bound fraction of heart protein, whereas the beta1 and beta3 were mostly cytosolic. There was a significant diminution of the amount of beta2 in the membrane fraction of the transgenic animals, resulting in a decrease in contractility of the heart and a decrease in L-type calcium current density in the myocyte. However, there were no distinguishable differences in beta1 and beta3 protein expression levels in the membrane bound fraction between transgenic and non-transgenic animals. Since the beta1 and beta3 isoforms only make up a small portion of the total beta subunit in the heart, slight changes in this fraction are not detectable using Western analysis. In contrast, beta1 and beta3 in skeletal muscle and brain, the predominant isoforms in these tissues, respectively, are membrane bound.

    Funded by: NHLBI NIH HHS: HL07382, HL22619

    Biochemical and biophysical research communications 2002;293;5;1405-11

  • Role of the beta(2) subunit of voltage-dependent calcium channels in the retinal outer plexiform layer.

    Ball SL, Powers PA, Shin HS, Morgans CW, Peachey NS and Gregg RG

    Research Service, Cleveland VA Medical Center, Cleveland, Ohio, USA.

    Purpose: Mutations in the alpha(1F) subunit of voltage-dependent calcium channels (VDCCs) have been shown to cause incomplete congenital stationary night blindness (CSNB2). The purpose of this study was to dentify which of the four beta subunits of VDCCs participates in the formation of this channel at the photoreceptor synapse and to determine how its absence affects visual processing.

    Methods: Mice without each of the four known beta subunits of VDCCs were generated by gene targeting and transgenic rescue (CNS-beta(1), -beta(2)) or by gene targeting alone (beta(3)) or were obtained from a commercial provider (beta(4)). Retinal function and visual sensitivity were examined by electroretinography and an active avoidance behavioral test, respectively. The structure of the retina and expression of the alpha(1F) subunit were examined at the light microscopic level and by immunohistochemistry.

    Results: Under dark-adapted conditions, CNS-beta(2)-null mice had a normal ERG a-wave, but did not have a normal b-wave. In addition, these mice showed decreased sensitivity to light. Both the a- and b-waves appear normal in the CNS-beta(1)-, beta(3)-, and beta(4)-null mice. Histologic analyses of all four mouse lines indicated that only the CNS-beta(2)-null mice had altered retinal morphology. Eyes of these mice had a thinner outer plexiform layer (OPL) than eyes of control animals. In addition, the labeling pattern of the alpha(1F) subunit in the OPL was altered in CNS-beta(2)-null mice.

    Conclusions: The normal distribution of the alpha(1F) subunit of the VDCCs in the OPL is dependent on the expression of the beta(2) subunit. The expression of both of these subunits is required for normal maintenance and/or formation of the OPL and synaptic transmission.

    Funded by: NEI NIH HHS: R01 EY 12354; NHLBI NIH HHS: P01 HL 47053

    Investigative ophthalmology & visual science 2002;43;5;1595-603

  • Novel Cav2.1 splice variants isolated from Purkinje cells do not generate P-type Ca2+ current.

    Tsunemi T, Saegusa H, Ishikawa K, Nagayama S, Murakoshi T, Mizusawa H and Tanabe T

    Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.

    The alpha(1)2.1 (alpha(1A)) subunits of P-type and Q-type Ca(2+) channels are encoded by a single gene, Cacna1a. Although these channels differ in the inactivation kinetics and sensitivity to omega-agatoxin IVA, the mechanism underlying these differences remains to be clarified. Alternative splicings of the Cacna1a transcript have been postulated to contribute to the respective properties, however, the splice variants responsible for P-type Ca(2+) channels have not been identified. To explore P-type-specific splice variants, we aimed at cloning alpha(1)2.1 from isolated mouse Purkinje cells using single-cell reverse transcription-PCR, because in Purkinje cells P-type currents dominate over the whole currents (>95%) with Q-type currents undetected. As a result, two novel splice variants were cloned. Compared with the previously cloned mouse alpha(1)2.1, two novel variants had additional 48 amino acids at the amino termini, six single amino acid changes, and splicing variations at the exon 46/47 boundary, which produced different carboxyl termini. Furthermore, one variant had one RNA editing site. However, electrophysiological and pharmacological studies indicated that these variants did not generate P-type current in cultured cells. These results suggest that P-type-specific splice variants may exist but that post-translational processing or modification by uncharacterized interacting proteins is also required for generating the P-type current.

    The Journal of biological chemistry 2002;277;9;7214-21

  • Influence of ethanol on thermoregulation: mapping quantitative trait loci.

    Crawshaw LI, Wallace HL, Christensen R and Crabbe JC

    Department of Biology, Portland State University, Portland, 97207, USA. crawshl@pdx.edu

    The genetic basis for the effects of ethanol on thermoregulation was investigated by utilizing recombinant inbred mouse strains from C57BL/6J and DBA/2J progenitor strains. Changes in core body temperature (T(c)) and the degree of fluctuation of T(c) were monitored in male mice following the administration of ethanol in an environment with cyclic changes in ambient temperature (T(a)). Changes in T(c) were utilized to assess ethanol-induced effects on regulated T(c), whereas fluctuations in T(c) were utilized to assess thermoregulatory disruption. Ethanol was administered intraperitoneally at 1.5, 2.5, and 3.5 g/kg for all strains. Change in T(c) and increase in tail temperature were also evaluated at 2.5 g/kg ethanol in a constant T(a) of 26 degrees C. Associations between the measured physiological responses and previously mapped genetic markers were used to identify quantitative trait loci (QTLs). This established probable chromosome locations for a number of genes for the responses. To our knowledge, this is the first report of QTLs that underlie changes in regulation as well as the disruption of a physiological regulatory system.

    Funded by: NIAAA NIH HHS: AA-10760, P60 AA010760

    Physiological genomics 2001;7;2;159-69

  • Mutations of calcium channel beta subunit genes in mice.

    Freise D, Himmerkus N, Schroth G, Trost C, Weissgerber P, Freichel M and Flockerzi V

    Institut für Pharmakologie und Toxikologie, Universität des Saarlandes, Homburg, Germany.

    Ca2+ influx through high voltage activated Ca2+ channels initiates a number of physiological processes including e.g. excitation-contraction coupling in cardiac myocytes and excitation-transcription coupling in neurones. The Ca2+ channels involved are complexes of a pore-forming alpha1 subunit, a transmembrane delta subunit disulfide-linked to an extracellular alpha2 subunit, a intracellular beta subunit and, at least in some tissues, a gamma subunit. Experimental analysis of beta subunit function comprises functional coexpression of its cDNA together with the cDNAs of the other subunits. This experimental approach can be supplemented by investigating functional alterations that result from the genetic elimination of Ca2+ channel beta genes in mice. Here we summarize the phenotype of mice deficient in the beta1 subunit, the beta3 subunit or the beta4 subunit, respectively.

    Biological chemistry 1999;380;7-8;897-902

  • beta subunit reshuffling modifies N- and P/Q-type Ca2+ channel subunit compositions in lethargic mouse brain.

    Burgess DL, Biddlecome GH, McDonough SI, Diaz ME, Zilinski CA, Bean BP, Campbell KP and Noebels JL

    Department of Neurology, Baylor College of Medicine, Houston, Texas 77030, USA.

    Neuronal voltage-dependent Ca2+ channels are heteromultimers of alpha1, beta, and alpha2delta subunits, and any one of five alpha1 subunits (alpha1A-E) may associate with one of four beta subunits (beta1-4). The specific alpha1-beta combination assembled determines single-channel properties, while variation in the proportion of each combination contributes to the functional diversity of neurons. The mouse mutant lethargic (lh) exhibits severe neurological defects due to a mutation that deletes the alpha1 subunit interaction domain of the beta4 subunit. Since beta subunits regulate critical alpha1 subunit properties in heterologous expression systems, loss of beta4 in lethargic could dramatically alter channel localization and behavior unless beta1-3 subunits can be used as substitutes in vivo. Here we demonstrate increased steady-state associations of alpha1A and alpha1B with the remaining beta1-3 subunits, without significant changes in beta1-3 mRNA abundance. The immunolocalization of alpha1A and alpha1B protein in lethargic brain is indistinguishable from wild-type by light microscopy. Furthermore, the measurement of large-amplitude P-type currents in dissociated lethargic Purkinje neurons indicates that these alpha1A-containing channels retain regulation by beta subunits. We conclude that several properties of alpha1A and alpha1B proteins are not uniquely regulated by beta4 in vivo and may be rescued by beta1-3 subunit reshuffling. The complex neurological manifestation of the lethargic mutation therefore emerges from loss of beta4 coupled with the widespread pairing of surrogate beta subunits with multiple Ca2+ channel subtypes. The existence of beta subunit reshuffling demonstrates that molecular plasticity of Ca2+ channel assembly, a normal feature of early brain development, is retained in the mature brain.

    Funded by: NHLBI NIH HHS: HL07121; NINDS NIH HHS: NS29709, R01NS36855

    Molecular and cellular neurosciences 1999;13;4;293-311

  • Ca2+ sparks in embryonic mouse skeletal muscle selectively deficient in dihydropyridine receptor alpha1S or beta1a subunits.

    Conklin MW, Powers P, Gregg RG and Coronado R

    Department of Physiology, University of Wisconsin Medical School, University of Wisconsin, Madison, Wisconsin 53706, USA.

    Ca2+ sparks are miniature Ca2+ release events from the sarcoplasmic reticulum of muscle cells. We examined the kinetics of Ca2+ sparks in excitation-contraction uncoupled myotubes from mouse embryos lacking the beta1 subunit and mdg embryos lacking the alpha1S subunit of the dihydropyridine receptor. Ca2+ sparks occurred spontaneously without a preferential location in the myotube. Ca2+ sparks had a broad distribution of spatial and temporal dimensions with means much larger than those reported in adult muscle. In normal myotubes (n = 248 sparks), the peak fluorescence ratio, DeltaF/Fo, was 1.6 +/- 0.6 (mean +/- SD), the full spatial width at half-maximal fluorescence (FWHM) was 3.6 +/- 1.1 micrometer and the full duration of individual sparks, Deltat, was 145 +/- 64 ms. In beta-null myotubes (n = 284 sparks), DeltaF/Fo = 1.9 +/- 0.4, FWHM = 5.1 +/- 1.5 micrometer, and Deltat = 168 +/- 43 ms. In mdg myotubes (n = 426 sparks), DeltaF/Fo = 1 +/- 0.5, the FWHM = 2.5 +/- 1.1 micrometer, and Deltat = 97 +/- 50 ms. Thus, Ca2+ sparks in mdg myotubes were significantly dimmer, smaller, and briefer than Ca2+ sparks in normal or beta-deficient myotubes. In all cell types, the frequency of sparks, DeltaF/Fo, and FWHM were gradually decreased by tetracaine and increased by caffeine. Both results confirmed that Ca2+ sparks of resting embryonic muscle originated from spontaneous openings of ryanodine receptor channels. We conclude that dihydropyridine receptor alpha1S and beta1 subunits participate in the control of Ca2+ sparks in embryonic skeletal muscle. However, excitation-contraction coupling is not essential for Ca2+ spark formation in these cells.

    Funded by: NHLBI NIH HHS: HL-47053

    Biophysical journal 1999;76;2;657-69

  • Absence of the beta subunit (cchb1) of the skeletal muscle dihydropyridine receptor alters expression of the alpha 1 subunit and eliminates excitation-contraction coupling.

    Gregg RG, Messing A, Strube C, Beurg M, Moss R, Behan M, Sukhareva M, Haynes S, Powell JA, Coronado R and Powers PA

    Waisman Center, University of Wisconsin, Madison 53705, USA. gregg@waisman.wisc.edu

    The multisubunit (alpha 1s, alpha 2/delta, beta 1, and gamma) skeletal muscle dihydropyridine receptor transduces transverse tubule membrane depolarization into release of Ca2+ from the sarcoplasmic reticulum, and also acts as an L-type Ca2+ channel. The alpha 1s subunit contains the voltage sensor and channel pore, the kinetics of which are modified by the other subunits. To determine the role of the beta 1 subunit in channel activity and excitation-contraction coupling we have used gene targeting to inactivate the beta 1 gene. beta 1-null mice die at birth from asphyxia. Electrical stimulation of beta 1-null muscle fails to induce twitches, however, contractures are induced by caffeine. In isolated beta 1-null myotubes, action potentials are normal, but fail to elicit a Ca2+ transient. L-type Ca2+ current is decreased 10- to 20-fold in the beta 1-null cells compared with littermate controls. Immunohistochemistry of cultured myotubes shows that not only is the beta 1 subunit absent, but the amount of alpha 1s in the membrane also is undetectable. In contrast, the beta 1 subunit is localized appropriately in dysgenic, mdg/mdg, (alpha 1s-null) cells. Therefore, the beta 1 subunit may not only play an important role in the transport/insertion of the alpha 1s subunit into the membrane, but may be vital for the targeting of the muscle dihydropyridine receptor complex to the transverse tubule/sarcoplasmic reticulum junction.

    Proceedings of the National Academy of Sciences of the United States of America 1996;93;24;13961-6

  • The inducible form of nitric oxide synthase (NOS2) isolated from murine macrophages maps near the nude mutation on mouse chromosome 11.

    Mock BA, Krall MM, Byrd LG, Chin H, Barton CH, Charles I, Liew FY and Blackwell J

    Laboratory of Genetics, NCI, National Institutes of Health, Bethesda, MD 20892, USA.

    Nitric oxide synthase has been shown to mediate streptozocin-induced diabetes and to act as an antimicrobial agent in murine macrophages. Using a cDNA probe for the inducible form of nitric oxide synthase (Nos2) isolated from murine macrophages we have determined that the gene maps within 1 cM of the nude mutation on mouse Chromosome 11. The position of Nos2 was also mapped relative to the markers 115, Evi2, Cchlbl (previously unmapped), and Gfap. This map location is discussed relative to map locations for disease susceptibility loci involved in mediating cutaneous leishmaniasis (ScII) and autoimmune type-I diabetes (Idd4).

    European journal of immunogenetics : official journal of the British Society for Histocompatibility and Immunogenetics 1994;21;4;231-8

  • Cloning and expression of a cardiac/brain beta subunit of the L-type calcium channel.

    Perez-Reyes E, Castellano A, Kim HS, Bertrand P, Baggstrom E, Lacerda AE, Wei XY and Birnbaumer L

    Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030.

    The skeletal muscle dihydropyridine receptor/Ca2+ channel is composed of five protein components (alpha 1, alpha 2 delta, beta, and gamma). Only two such components, alpha 1 and alpha 2, have been identified in heart. The present study reports the cloning and expression of a novel beta gene that is expressed in heart, lung, and brain. Coexpression of this beta with a cardiac alpha 1 in Xenopus oocytes causes the following changes in Ca2+ channel activity: it increases peak currents, accelerates activation kinetics, and shifts the current-voltage relationship toward more hyperpolarized potentials. It also increases dihydropyridine binding to alpha 1 in COS cells. These results indicate that the cardiac L-type Ca2+ channel has a similar subunit structure as in skeletal muscle, and provides evidence for the modulatory role of the beta subunit.

    Funded by: NHLBI NIH HHS: HL-37044

    The Journal of biological chemistry 1992;267;3;1792-7

  • Cloning and tissue-specific expression of the brain calcium channel beta-subunit.

    Pragnell M, Sakamoto J, Jay SD and Campbell KP

    Howard Hughes Medical Institute, Program in Neuroscience, University of Iowa College of Medicine, Iowa City 52242.

    A cDNA clone encoding a protein with high homology to the beta-subunit of the rabbit skeletal muscle dihydropyridine-sensitive calcium channel was isolated from a rat brain cDNA library. This rat brain beta-subunit cDNA hybridizes to a 3.4 kb message that is expressed in high levels in the cerebral hemispheres and hippocampus but is significantly reduced in cerebellum. The open reading frame encodes 597 amino acids with a predicted mass of 65 679 Da which is 82% homologous with the skeletal muscle beta-subunit. The brain cDNA encodes a unique 153 amino acid C-terminus and predicts the absence of a muscle-specific 50 amino acid internal segment. It also encodes numerous consensus phosphorylation sites suggesting a role in calcium channel regulation. The corresponding human beta-subunit gene was localized to chromosome 17. Hence the encoded brain beta-subunit, which has a primary structure highly similar to its isoform in skeletal muscle, may have a comparable role as an integral regulatory component of a neuronal calcium channel.

    FEBS letters 1991;291;2;253-8

  • Primary structure of the beta subunit of the DHP-sensitive calcium channel from skeletal muscle.

    Ruth P, Röhrkasten A, Biel M, Bosse E, Regulla S, Meyer HE, Flockerzi V and Hofmann F

    Institut für Physiologische Chemie, Medizinische Fakultät, Homburg/Saar, Federal Republic of Germany.

    Complementary DNAs for the beta subunit of the dihydropyridine-sensitive calcium channel of rabbit skeletal muscle were isolated on the basis of peptide sequences derived from the purified protein. The deduced primary structure is without homology to other known protein sequences and is consistent with the beta subunit being a peripheral membrane protein associated with the cytoplasmic aspect of the sarcolemma. The protein contains sites that might be expected to be preferentially phosphorylated by protein kinase C and guanosine 3',5'-monophosphate-dependent protein kinase. A messenger RNA for this protein appears to be expressed in brain.

    Science (New York, N.Y.) 1989;245;4922;1115-8

Gene lists (5)

Gene List Source Species Name Description Gene count
L00000001 G2C Mus musculus Mouse PSD Mouse PSD adapted from Collins et al (2006) 1080
L00000008 G2C Mus musculus Mouse PSP Mouse PSP adapted from Collins et al (2006) 1121
L00000062 G2C Mus musculus BAYES-COLLINS-MOUSE-PSD-CONSENSUS Mouse cortex PSD consensus 984
L00000070 G2C Mus musculus BAYES-COLLINS-HUMAN-PSD-FULL Human cortex biopsy PSD full list (ortho) 1461
L00000072 G2C Mus musculus BAYES-COLLINS-MOUSE-PSD-FULL Mouse cortex PSD full list 1556
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EUROSPIN (FP7-HEALTH-241498), SynSys (FP7-HEALTH-242167) and GENCODYS (FP7-HEALTH-241995).

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