Protein found in humans
Calcium channel, voltage-dependent, gamma subunit 2 , also known asCACNG2 orstargazin is aprotein that in humans is encoded by theCACNG2 gene .[ 5]
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 anintegral 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 aspetit-mal or spike-wave seizures. This gene is a member of the neuronal calcium channel gamma subunit gene subfamily of thePMP-22 /EMP/MP20 family.[ 5]
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 inLTP .
Clinical significance [ edit ] Disruptions ofCACNG2 have been implicated inautism .[ 6]
CACNG2 has been shown tointeract withGRIA4 ,[ 7] DLG4 ,[ 7] [ 8] [ 9]
^a b c GRCh38: Ensembl release 89: ENSG00000166862 –Ensembl , May 2017^a b c GRCm38: Ensembl release 89: ENSMUSG00000019146 –Ensembl , May 2017^ "Human PubMed Reference:" .National Center for Biotechnology Information, U.S. National Library of Medicine .^ "Mouse PubMed Reference:" .National Center for Biotechnology Information, U.S. National Library of Medicine .^a b "Entrez Gene: CACNG2 calcium channel, voltage-dependent, gamma subunit 2" .^ Brandler WM, Antaki D, Gujral M, Noor A, Rosanio G, Chapman TR, et al. (April 2016)."Frequency and Complexity of De Novo Structural Mutation in Autism" .American Journal of Human Genetics .98 (4):667– 679.doi :10.1016/j.ajhg.2016.02.018 .PMC 4833290 PMID 27018473 . ^a b Chen L, Chetkovich DM, Petralia RS, Sweeney NT, Kawasaki Y, Wenthold RJ, et al. (2000). "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 . ^ 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 . ^ Deng F, Price MG, Davis CF, Mori M, Burgess DL (July 2006)."Stargazin and other transmembrane AMPA receptor regulating proteins interact with synaptic scaffolding protein MAGI-2 in brain" .The Journal of Neuroscience .26 (30):7875– 7884.doi :10.1523/JNEUROSCI.1851-06.2006 PMC 6674230 PMID 16870733 . 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.Bibcode :2006JAChS.128.5913S .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.Bibcode :2006JBiCh.28123908B .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 . This article incorporates text from theUnited States National Library of Medicine , which is in thepublic domain .
