The physiological functions controlled by T-type channels are intrinsically dependent on their gating properties, and alteration of T-type channel activity is linked to several human disorders. Therefore, it is essential to develop a clear understanding of the structural determinants responsible for the unique gating features of T-type channels. Here, we have investigated the specific role of the carboxy terminal region by creating a series a deletion constructs expressed in tsA-201 cells and analyzing them by patch clamp electrophysiology. Our data reveal that the proximal region of the carboxy terminus contains a structural determinant essential for shaping several gating aspects of Cav3.3 channels, including voltage-dependence of activation and inactivation, inactivation kinetics, and coupling between the voltage sensing and the pore opening of the channel. Altogether, our data are consistent with a model in which the carboxy terminus stabilizes the channel in a closed state.

Center of Biosciences Institute of Molecular Physiology and Genetics Academy of Sciences Bratislava Slovakia

Department of Physiology and Pharmacology Cumming School of Medicine University of Calgary Calgary Canada

Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo nam 2 16610 Prague Czech Republic

Zobrazit více v PubMed

Perez-Reyes E. Molecular physiology of low-voltage-activated t-type calcium channels. Physiol Rev. 2003;83:117–161. doi: 10.1152/physrev.00018.2002. PubMed DOI

Perez-Reyes E, Cribbs LL, Daud A, et al. Molecular characterization of a neuronal low-voltage-activated T-type calcium channel. Nature. 1998;391:896–900. doi: 10.1038/36110. PubMed DOI

Cribbs LL, Lee JH, Yang J, et al. Cloning and characterization of alpha1H from human heart, a member of the T-type Ca2+ channel gene family. Circ Res. 1998;83:103–109. doi: 10.1161/01.RES.83.1.103. PubMed DOI

Lee JH, Daud AN, Cribbs LL, et al. Cloning and expression of a novel member of the low voltage-activated T-type calcium channel family. J Neurosci. 1999;19:1912–1921. doi: 10.1523/JNEUROSCI.19-06-01912.1999. PubMed DOI PMC

Yunker AM, Sharp AH, Sundarraj S, Ranganathan V, Copeland TD, McEnery MW. Immunological characterization of T-type voltage-dependent calcium channel CaV3.1 (alpha 1G) and CaV3.3 (alpha 1I) isoforms reveal differences in their localization, expression, and neural development. Neuroscience. 2003;117:321–335. doi: 10.1016/S0306-4522(02)00936-3. PubMed DOI

Talley EM, Cribbs LL, Lee JH, Daud A, Perez-Reyes E, Bayliss DA. Differential distribution of three members of a gene family encoding low voltage-activated (T-type) calcium channels. J Neurosci. 1999;19:1895–1911. doi: 10.1523/JNEUROSCI.19-06-01895.1999. PubMed DOI PMC

McKay BE, McRory JE, Molineux ML, et al. Ca(V)3 T-type calcium channel isoforms differentially distribute to somatic and dendritic compartments in rat central neurons. Eur J Neurosci. 2006;24:2581–2594. doi: 10.1111/j.1460-9568.2006.05136.x. PubMed DOI

García-Delgado N, Velasco M, Sánchez-Soto C, Díaz-García CM, Hiriart M. Calcium Channels in Postnatal Development of Rat Pancreatic Beta Cells and Their Role in Insulin Secretion. Front Endocrinol (Lausanne) 2018;9:40. doi: 10.3389/fendo.2018.00040. PubMed DOI PMC

Park JY, Ahn HJ, Gu JG, et al. Molecular identification of Ca2+ channels in human sperm. Exp Mol Med. 2003;35:285–292. doi: 10.1038/emm.2003.39. PubMed DOI

Deng J, He P, Zhong X, Wang Q, Li L, Song B. Identification of T-type calcium channels in the interstitial cells of Cajal in rat bladder. Urology. 2012;80:1389.e1–1389.e7. doi: 10.1016/j.urology.2012.07.031. PubMed DOI

Cain SM, Snutch TP. T-type calcium channels in burst-firing, network synchrony, and epilepsy. Biochim Biophys Acta. 2013;1828:1572–1578. doi: 10.1016/j.bbamem.2012.07.028. PubMed DOI

Weiss N, Zamponi GW. T-type calcium channels: from molecule to therapeutic opportunities. Int J Biochem Cell Biol. 2019;108:34–39. doi: 10.1016/j.biocel.2019.01.008. PubMed DOI

Williams SR, Tóth TI, Turner JP, Hughes SW, Crunelli V. The ‘window’ component of the low threshold Ca2+ current produces input signal amplification and bistability in cat and rat thalamocortical neurones. J Physiol. 1997;505:689–705. doi: 10.1111/j.1469-7793.1997.689ba.x. PubMed DOI PMC

Hughes SW, Cope DW, Blethyn KL, Crunelli V. Cellular mechanisms of the slow (<1 Hz) oscillation in thalamocortical neurons in vitro. Neuron. 2002;33:947–958. doi: 10.1016/S0896-6273(02)00623-2. PubMed DOI

Staes M, Talavera K, Klugbauer N, et al. The amino side of the C-terminus determines fast inactivation of the T-type calcium channel alpha1G. J Physiol. 2001;530:35–45. doi: 10.1111/j.1469-7793.2001.0035m.x. PubMed DOI PMC

Hamid J, Peloquin JB, Monteil A, Zamponi GW. Determinants of the differential gating properties of Cav3.1 and Cav3.3 T-type channels: a role of domain IV. Neuroscience. 2006;143:717–728. doi: 10.1016/j.neuroscience.2006.08.023. PubMed DOI

Kang HW, Park JY, Lee JH. Distinct contributions of different structural regions to the current kinetics of the Cav3.3 T-type Ca2+ channel. Biochim Biophys Acta. 2008;1778:2740–2748. doi: 10.1016/j.bbamem.2008.08.002. PubMed DOI

Baumgart JP, Vitko I, Bidaud I, Kondratskyi A, Lory P, Perez-Reyes E. I-II loop structural determinants in the gating and surface expression of low voltage-activated calcium channels. PLoS One. 2008;3:e2976. doi: 10.1371/journal.pone.0002976. PubMed DOI PMC

Karmažínová M, Jašková K, Griac P, Perez-Reyes E, Lacinová Ľ. Contrasting the roles of the I-II loop gating brake in CaV3.1 and CaV3.3 calcium channels. Pflugers Arch. 2015;467:2519–2527. doi: 10.1007/s00424-015-1728-y. PubMed DOI

Agler HL, Evans J, Tay LH, Anderson MJ, Colecraft HM, Yue DT. G protein-gated inhibitory module of N-type (ca(v)2.2) ca2+ channels. Neuron. 2005;46:891–904. doi: 10.1016/j.neuron.2005.05.011. PubMed DOI

Karmažínová M, Baumgart JP, Perez-Reyes E, Lacinová L. The voltage dependence of gating currents of the neuronal CA(v)3.3 channel is determined by the gating brake in the I-II loop. Pflugers Arch. 2011;461:461–468. doi: 10.1007/s00424-011-0937-2. PubMed DOI PMC

Astori S, Wimmer RD, Prosser HM, et al. The ca(V)3.3 calcium channel is the major sleep spindle pacemaker in thalamus. Proc Natl Acad Sci U S A. 2011;108:13823–13828. doi: 10.1073/pnas.1105115108. PubMed DOI PMC

Weiss N, Hameed S, Fernández-Fernández JM, et al. A ca(v)3.2/syntaxin-1A signaling complex controls T-type channel activity and low-threshold exocytosis. J Biol Chem. 2012;287:2810–2818. doi: 10.1074/jbc.M111.290882. PubMed DOI PMC

Weiss N, Zamponi GW. Regulation of voltage-gated calcium channels by synaptic proteins. Adv Exp Med Biol. 2012;740:759–775. doi: 10.1007/978-94-007-2888-2_33. PubMed DOI

Simms BA, Zamponi GW. Neuronal voltage-gated calcium channels: structure, function, and dysfunction. Neuron. 2014;82:24–45. doi: 10.1016/j.neuron.2014.03.016. PubMed DOI

Weiss N, Zamponi GW. Trafficking of neuronal calcium channels. Neuronal Signaling. 2017;1:NS20160003. doi: 10.1042/NS20160003. PubMed DOI PMC

Frazier CJ, Serrano JR, George EG, et al. Gating kinetics of the alpha1I T-type calcium channel. J Gen Physiol. 2001;118:457–470. doi: 10.1085/jgp.118.5.457. PubMed DOI PMC

Serrano JR, Perez-Reyes E, Jones SW. State-dependent inactivation of the alpha1G T-type calcium channel. J Gen Physiol. 1999;114:185–201. doi: 10.1085/jgp.114.2.185. PubMed DOI PMC

Lee N, Jeong S, Kim KC, et al. Ca2+ Regulation of Cav3.3 T-type Ca2+ Channel Is Mediated by Calmodulin. Mol Pharmacol. 2017;92:347–357. doi: 10.1124/mol.117.108530. PubMed DOI PMC

Electrophysiological and computational analysis of Cav3.2 channel variants associated with familial trigeminal neuralgia

Selective inhibition of neuronal Cav3.3 T-type calcium channels by TAT-based channel peptide

A rare CACNA1H variant associated with amyotrophic lateral sclerosis causes complete loss of Cav3.2 T-type channel activity

Compound heterozygous CACNA1H mutations associated with severe congenital amyotrophy