CACNG2

Calcium channel, voltage-dependent, gamma subunit 2, also known as CACNG2 or stargazin is a protein that in humans is encoded by the CACNG2 gene.

CACNG2
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 3JXT
Identifiers
Aliases	CACNG2, MRD10, calcium voltage-gated channel auxiliary subunit gamma 2
External IDs	OMIM: 602911; MGI: 1316660; HomoloGene: 4432; GeneCards: CACNG2; OMA:CACNG2 - orthologs
Gene location (Human) Chr. Chromosome 22 (human) Band 22q12.3 Start 36,560,857 bp End 36,703,752 bp
Gene location (Mouse) Chr. Chromosome 15 (mouse) Band 15 E1|15 36.92 cM Start 77,875,948 bp End 78,004,228 bp
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in right hemisphere of cerebellum postcentral gyrus Brodmann area 46 superior frontal gyrus prefrontal cortex right frontal lobe dorsolateral prefrontal cortex entorhinal cortex Brodmann area 9 anterior cingulate cortex Top expressed in anterior horn of spinal cord lumbar subsegment of spinal cord cerebellar vermis lobe of cerebellum Medulla Oblongata medial dorsal nucleus primary motor cortex medial vestibular nucleus facial motor nucleus medial geniculate nucleus More reference expression data BioGPS More reference expression data
Gene ontology Molecular function voltage-gated ion channel activity protein binding channel regulator activity calcium channel activity voltage-gated calcium channel activity ionotropic glutamate receptor binding Cellular component voltage-gated calcium channel complex integral component of membrane endocytic vesicle membrane membrane plasma membrane AMPA glutamate receptor complex cell junction neuron projection synapse postsynaptic density membrane somatodendritic compartment cytosol cell surface postsynaptic density cerebellar mossy fiber Schaffer collateral - CA1 synapse hippocampal mossy fiber to CA3 synapse glutamatergic synapse integral component of postsynaptic density membrane Biological process membrane hyperpolarization transmission of nerve impulse regulation of membrane potential regulation of ion transmembrane transport membrane depolarization nervous system process ion transport regulation of AMPA receptor activity neuromuscular junction development calcium ion transport calcium ion transmembrane transport neurotransmitter receptor transport, postsynaptic endosome to lysosome postsynaptic neurotransmitter receptor diffusion trapping neurotransmitter receptor internalization protein targeting to membrane response to calcium ion eye blink reflex positive regulation of protein localization to basolateral plasma membrane positive regulation of AMPA receptor activity regulation of postsynaptic membrane neurotransmitter receptor levels neurotransmitter receptor localization to postsynaptic specialization membrane positive regulation of synaptic transmission, glutamatergic cardiac conduction Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 10369 12300 Ensembl ENSG00000166862 ENSMUSG00000019146 UniProt Q9Y698 O88602 RefSeq (mRNA) NM_006078 NM_001379051 NM_007583 RefSeq (protein) NP_006069 NP_001365980 NP_031609 Location (UCSC) Chr 22: 36.56 – 36.7 Mb Chr 15: 77.88 – 78 Mb PubMed search
Wikidata
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Function

L-type calcium channels are composed of five subunits. The protein encoded by this gene represents one of these subunits, gamma, and is one of several gamma subunit proteins. It is an integral membrane protein that is thought to stabilize the calcium channel in an inactive (closed) state. This protein is similar to the mouse stargazin protein, mutations in which having been associated with absence seizures, also known as petit-mal or spike-wave seizures. This gene is a member of the neuronal calcium channel gamma subunit gene subfamily of the PMP-22/EMP/MP20 family.

Stargazin is involved in the transportation of AMPA receptors to the synaptic membrane, and the regulation of their receptor rate constants — via its extracellular domain — once it is there. As it is highly expressed throughout the cerebral cortex, it is likely to have an important role in learning within these areas, due to the importance of AMPA receptors in LTP.

Clinical significance

Disruptions of CACNG2 have been implicated in autism.

Interactions

CACNG2 has been shown to interact with GRIA4, DLG4, and MAGI2.

See also

• Voltage-dependent calcium channel

Further reading

• Powers PA, Liu S, Hogan K, Gregg RG (May 1993). "Molecular characterization of the gene encoding the gamma subunit of the human skeletal muscle 1,4-dihydropyridine-sensitive Ca2 channel (CACNLG), cDNA sequence, gene structure, and chromosomal location". The Journal of Biological Chemistry. 268 (13): 9275–9279. doi:10.1016/S0021-9258(18)98346-8. PMID 8387489.
• Black JL, Lennon VA (April 1999). "Identification and cloning of putative human neuronal voltage-gated calcium channel gamma-2 and gamma-3 subunits: neurologic implications". Mayo Clinic Proceedings. 74 (4): 357–361. doi:10.4065/74.4.357. PMID 10221464.
• Burgess DL, Matsuura T, Ashizawa T, Noebels JL (January 2000). "Genetic localization of the Ca2 channel gene CACNG2 near SCA10 on chromosome 22q13". Epilepsia. 41 (1): 24–27. doi:10.1111/j.1528-1157.2000.tb01500.x. PMID 10643919.
• Chen L, Chetkovich DM, Petralia RS, Sweeney NT, Kawasaki Y, Wenthold RJ, et al. (2001). "Stargazin regulates synaptic targeting of AMPA receptors by two distinct mechanisms". Nature. 408 (6815): 936–943. Bibcode:2000Natur.408..936C. doi:10.1038/35050030. PMID 11140673. S2CID 4427689.
• Burgess DL, Gefrides LA, Foreman PJ, Noebels JL (February 2001). "A cluster of three novel Ca2 channel gamma subunit genes on chromosome 19q13.4: evolution and expression profile of the gamma subunit gene family". Genomics. 71 (3): 339–350. doi:10.1006/geno.2000.6440. PMID 11170751.
• Choi J, Ko J, Park E, Lee JR, Yoon J, Lim S, et al. (April 2002). "Phosphorylation of stargazin by protein kinase A regulates its interaction with PSD-95". The Journal of Biological Chemistry. 277 (14): 12359–12363. doi:10.1074/jbc.M200528200. PMID 11805122.
• Schnell E, Sizemore M, Karimzadegan S, Chen L, Bredt DS, Nicoll RA (October 2002). "Direct interactions between PSD-95 and stargazin control synaptic AMPA receptor number". Proceedings of the National Academy of Sciences of the United States of America. 99 (21): 13902–13907. Bibcode:2002PNAS...9913902S. doi:10.1073/pnas.172511199. PMC 129795. PMID 12359873.
• Moss FJ, Dolphin AC, Clare JJ (September 2003). "Human neuronal stargazin-like proteins, gamma2, gamma3 and gamma4; an investigation of their specific localization in human brain and their influence on CaV2.1 voltage-dependent calcium channels expressed in Xenopus oocytes". BMC Neuroscience. 4: 23. doi:10.1186/1471-2202-4-23. PMC 270087. PMID 14505496.
• Tomita S, Fukata M, Nicoll RA, Bredt DS (March 2004). "Dynamic interaction of stargazin-like TARPs with cycling AMPA receptors at synapses". Science. 303 (5663): 1508–1511. Bibcode:2004Sci...303.1508T. doi:10.1126/science.1090262. PMID 15001777. S2CID 46012559.
• Collins JE, Wright CL, Edwards CA, Davis MP, Grinham JA, Cole CG, et al. (2005). "A genome annotation-driven approach to cloning the human ORFeome". Genome Biology. 5 (10): R84. doi:10.1186/gb-2004-5-10-r84. PMC 545604. PMID 15461802.
• Yamazaki M, Ohno-Shosaku T, Fukaya M, Kano M, Watanabe M, Sakimura K (December 2004). "A novel action of stargazin as an enhancer of AMPA receptor activity". Neuroscience Research. 50 (4): 369–374. doi:10.1016/j.neures.2004.10.002. PMID 15567474. S2CID 407088.
• Priel A, Kolleker A, Ayalon G, Gillor M, Osten P, Stern-Bach Y (March 2005). "Stargazin reduces desensitization and slows deactivation of the AMPA-type glutamate receptors". The Journal of Neuroscience. 25 (10): 2682–2686. doi:10.1523/JNEUROSCI.4834-04.2005. PMC 6725153. PMID 15758178.
• Stiffler MA, Grantcharova VP, Sevecka M, MacBeath G (May 2006). "Uncovering quantitative protein interaction networks for mouse PDZ domains using protein microarrays". Journal of the American Chemical Society. 128 (17): 5913–5922. doi:10.1021/ja060943h. PMC 2533859. PMID 16637659.
• Bedoukian MA, Weeks AM, Partin KM (August 2006). "Different domains of the AMPA receptor direct stargazin-mediated trafficking and stargazin-mediated modulation of kinetics". The Journal of Biological Chemistry. 281 (33): 23908–23921. doi:10.1074/jbc.M600679200. PMID 16793768.
• Körber C, Werner M, Hoffmann J, Sager C, Tietze M, Schmid SM, et al. (June 2007). "Stargazin interaction with alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors is critically dependent on the amino acid at the narrow constriction of the ion channel". The Journal of Biological Chemistry. 282 (26): 18758–18766. doi:10.1074/jbc.M611182200. PMID 17483093.

External links

• CACNG2 protein, human at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• CACNG2 human gene location in the UCSC Genome Browser.
• CACNG2 human gene details in the UCSC Genome Browser.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.