Calcium channel, voltage-dependent, T type, alpha 1H subunit, also known as CACNA1H, is a protein which in humans is encoded by the CACNA1Hgene.[1][2][3]
This gene encodes Cav3.2, a T-type member of the α1 subunit family, a protein in the voltage-dependent calcium channel complex. Calcium channels mediate the influx of calcium ions into the cell upon membrane polarization and consist of a complex of α1, α2δ, β, and γ subunits in a 1:1:1:1 ratio. The α1 subunit has 24 transmembrane segments and forms the pore through which ions pass into the cell. There are multiple isoforms of each of the proteins in the complex, either encoded by different genes or the result of alternative splicing of transcripts. Alternate transcriptional splice variants, encoding different isoforms, have been characterized for the gene described here.[1]
Clinical significance
Studies suggest certain mutations in this gene lead to childhood absence epilepsy (CAE).[4] Variants of Cav3.2 with increased channel activity contribute to susceptibility to idiopathic generalized epilepsy (IGE), but are not sufficient to induce epilepsy on their own.[5] The SFARIgene database lists CACNA1H with an autism score of 2.1, indicating a candidate causal relationship with autism.
↑Catterall WA, Perez-Reyes E, Snutch TP, Striessnig J (December 2005). "International Union of Pharmacology. XLVIII. Nomenclature and structure-function relationships of voltage-gated calcium channels". Pharmacol. Rev. 57 (4): 411–25. doi:10.1124/pr.57.4.5. PMID16382099.
↑Chen Y, Lu J, Pan H, Zhang Y, Wu H, Xu K, Liu X, Jiang Y, Bao X, Yao Z, Ding K, Lo WH, Qiang B, Chan P, Shen Y, Wu X (August 2003). "Association between genetic variation of CACNA1H and childhood absence epilepsy". Ann. Neurol. 54 (2): 239–43. doi:10.1002/ana.10607. PMID12891677.
↑Heron SE, Khosravani H, Varela D, Bladen C, Williams TC, Newman MR, Scheffer IE, Berkovic SF, Mulley JC, Zamponi GW (December 2007). "Extended spectrum of idiopathic generalized epilepsies associated with CACNA1H functional variants". Ann. Neurol. 62 (6): 560–8. doi:10.1002/ana.21169. PMID17696120.
Cribbs LL, Lee JH, Yang J, et al. (1998). "Cloning and characterization of alpha1H from human heart, a member of the T-type Ca2+ channel gene family". Circ. Res. 83 (1): 103–9. doi:10.1161/01.res.83.1.103. PMID9670923.
Williams ME, Washburn MS, Hans M, et al. (1999). "Structure and functional characterization of a novel human low-voltage activated calcium channel". J. Neurochem. 72 (2): 791–9. doi:10.1046/j.1471-4159.1999.0720791.x. PMID9930755.
Perez-Reyes E, Lee JH, Cribbs LL (1999). "Molecular characterization of two members of the T-type calcium channel family". Ann. N. Y. Acad. Sci. 868: 131–43. doi:10.1111/j.1749-6632.1999.tb11283.x. PMID10414291.
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Jagannathan S, Punt EL, Gu Y, et al. (2002). "Identification and localization of T-type voltage-operated calcium channel subunits in human male germ cells. Expression of multiple isoforms". J. Biol. Chem. 277 (10): 8449–56. doi:10.1074/jbc.M105345200. PMID11751928.
Mariot P, Vanoverberghe K, Lalevee N, et al. (2002). "Overexpression of an alpha 1H (Cav3.2) T-type calcium channel during neuroendocrine differentiation of human prostate cancer cells". J. Biol. Chem. 277 (13): 10824–33. doi:10.1074/jbc.M108754200. PMID11799114.
Shin JB, Martinez-Salgado C, Heppenstall PA, Lewin GR (2003). "A T-type calcium channel required for normal function of a mammalian mechanoreceptor". Nat. Neurosci. 6 (7): 724–30. doi:10.1038/nn1076. PMID12808460.
Wolfe JT, Wang H, Howard J, et al. (2003). "T-type calcium channel regulation by specific G-protein betagamma subunits". Nature. 424 (6945): 209–13. doi:10.1038/nature01772. PMID12853961.
Kaku T, Lee TS, Arita M, et al. (2004). "The gating and conductance properties of Cav3.2 low-voltage-activated T-type calcium channels". Jpn. J. Physiol. 53 (3): 165–72. doi:10.2170/jjphysiol.53.165. PMID14529577.
Welsby PJ, Wang H, Wolfe JT, et al. (2003). "A mechanism for the direct regulation of T-type calcium channels by Ca2+/calmodulin-dependent kinase II". J. Neurosci. 23 (31): 10116–21. PMID14602827.
Chen CC, Lamping KG, Nuno DW, et al. (2003). "Abnormal coronary function in mice deficient in alpha1H T-type Ca2+ channels". Science. 302 (5649): 1416–8. doi:10.1126/science.1089268. PMID14631046.
Khosravani H, Altier C, Simms B, et al. (2004). "Gating effects of mutations in the Cav3.2 T-type calcium channel associated with childhood absence epilepsy". J. Biol. Chem. 279 (11): 9681–4. doi:10.1074/jbc.C400006200. PMID14729682.
Martin J, Han C, Gordon LA, et al. (2005). "The sequence and analysis of duplication-rich human chromosome 16". Nature. 432 (7020): 988–94. doi:10.1038/nature03187. PMID15616553.
