1
|
Chichorro JG, Gambeta E, Baggio DF, Zamponi GW. Voltage-gated Calcium Channels as Potential Therapeutic Targets in Migraine. THE JOURNAL OF PAIN 2024:104514. [PMID: 38522594 DOI: 10.1016/j.jpain.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 03/06/2024] [Accepted: 03/12/2024] [Indexed: 03/26/2024]
Abstract
Migraine is a complex and highly incapacitating neurological disorder that affects around 15% of the general population with greater incidence in women, often at the most productive age of life. Migraine physiopathology is still not fully understood, but it involves multiple mediators and events in the trigeminovascular system and the central nervous system. The identification of calcitonin gene-related peptide as a key mediator in migraine physiopathology has led to the development of effective and highly selective antimigraine therapies. However, this treatment is neither accessible nor effective for all migraine sufferers. Thus, a better understanding of migraine mechanisms and the identification of potential targets are still clearly warranted. Voltage-gated calcium channels (VGCCs) are widely distributed in the trigeminovascular system, and there is accumulating evidence of their contribution to the mechanisms associated with headache pain. Several drugs used in migraine abortive or prophylactic treatment target VGCCs, which probably contributes to their analgesic effect. This review aims to summarize the current evidence of VGGC contribution to migraine physiopathology and to discuss how current pharmacological options for migraine treatment interfere with VGGC function. PERSPECTIVE: Calcitonin gene-related peptide (CGRP) represents a major migraine mediator, but few studies have investigated the relationship between CGRP and VGCCs. CGRP release is calcium channel-dependent and VGGCs are key players in familial migraine. Further studies are needed to determine whether VGCCs are suitable molecular targets for treating migraine.
Collapse
Affiliation(s)
- Juliana G Chichorro
- Biological Sciences Sector, Department of Pharmacology, Federal University of Parana, Curitiba, Parana, Brazil.
| | - Eder Gambeta
- Cumming School of Medicine, Department of Clinical Neuroscience, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Darciane F Baggio
- Biological Sciences Sector, Department of Pharmacology, Federal University of Parana, Curitiba, Parana, Brazil
| | - Gerald W Zamponi
- Cumming School of Medicine, Department of Clinical Neuroscience, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
2
|
El Ghaleb Y, Flucher BE. Ca V3.3 Channelopathies. Handb Exp Pharmacol 2023; 279:263-288. [PMID: 36592228 DOI: 10.1007/164_2022_631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
CaV3.3 is the third member of the low-voltage-activated calcium channel family and the last to be recognized as disease gene. Previously, CACNA1I, the gene encoding CaV3.3, had been described as schizophrenia risk gene. More recently, de novo missense mutations in CACNA1I were identified in patients with variable degrees of neurodevelopmental disease with and without epilepsy. Their functional characterization indicated gain-of-function effects resulting in increased calcium load and hyperexcitability of neurons expressing CaV3.3. The amino acids mutated in the CaV3.3 disease variants are located in the vicinity of the channel's activation gate and thus are classified as gate-modifying channelopathy mutations. A persistent calcium leak during rest and prolonged calcium spikes due to increased voltage sensitivity of activation and slowed kinetics of channel inactivation, respectively, may be causal for the neurodevelopmental defects. The prominent expression of CaV3.3 in thalamic reticular nucleus neurons and its essential role in generating the rhythmic thalamocortical network activity are consistent with a role of the mutated channels in the etiology of epileptic seizures and thus suggest T-type channel blockers as a viable treatment option.
Collapse
Affiliation(s)
- Yousra El Ghaleb
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Bernhard E Flucher
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria.
| |
Collapse
|
3
|
Guidelli R, Becucci L. Deterministic model of Ca v3.1 Ca 2+ channel and a proposed sequence of its conformations. Bioelectrochemistry 2020; 136:107618. [PMID: 32795940 DOI: 10.1016/j.bioelechem.2020.107618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/29/2020] [Accepted: 07/21/2020] [Indexed: 10/23/2022]
Abstract
A family of current-time curves of T-type Cav3.1 Ca2+ channels available in the literature is simulated by a kinetic model differing from that used for the interpretation of all salient features of Na+ and Shaker K+ channels by the insertion of a multiplying factor expressing the difference between the working potential ϕ and the reversal potential ϕr. This deterministic model is also used to simulate experimental curves taken from the literature for steady-state 'fast inactivation' and for a gradual passage from fast to 'slow inactivation'. A depolarizing pulse induces fast or slow inactivation depending on whether it lasts 100-500 ms or about 1 min, and is believed to cause a collapse of the central pore near the selectivity filter (SF). A number of features of fast and slow inactivation of Cav3.1 Ca2+ channels are qualitatively interpreted on the basis of a sequence of conformational states. Briefly, the conformation responsible for 'fast inactivation' is assumed to have the activation gate open and the inactivation gate (i.e., the SF) inactive. Immediately after a depolarizing pulse, this conformation is inactive and requires a sufficiently long rest time at a far negative holding potential to recover from inactivation. 'Slow inactivation' is ascribed to a different conformation with the activation gate closed and the SF inactive.
Collapse
Affiliation(s)
- Rolando Guidelli
- Department of Chemistry "Ugo Schiff", Florence University, Via della Lastruccia 3, 50019 Sesto Fiorentino (Firenze), Italy.
| | - Lucia Becucci
- Department of Chemistry "Ugo Schiff", Florence University, Via della Lastruccia 3, 50019 Sesto Fiorentino (Firenze), Italy
| |
Collapse
|
4
|
Cmarko L, Weiss N. Selective inhibition of neuronal Ca v3.3 T-type calcium channels by TAT-based channel peptide. Mol Brain 2020; 13:95. [PMID: 32560664 PMCID: PMC7304182 DOI: 10.1186/s13041-020-00636-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 06/12/2020] [Indexed: 02/08/2023] Open
Abstract
Low-voltage-activated Cav3 calcium channels (T-type) play an essential role in the functioning of the nervous system where they support oscillatory activities that relie on several channel molecular determinants that shape their unique gating properties. In a previous study, we documented the important role of the carboxy proximal region in the functioning of Cav3.3 channels. Here, we explore the ability of a TAT-based cell penetrating peptide containing this carboxy proximal region (TAT-C3P) to modulate the activity of Cav3 channels. We show that chronic application of TAT-C3P on tsA-201 cells expressing Cav3 channels selectively inhibits Cav3.3 channels without affecting Cav3.1 and Cav3.2 channels. Therefore, the TAT-C3P peptide described in this study represents a new tool to address the specific physiological role of Cav3.3 channels, and to potentially enhance our understanding of Cav3.3 in disease.
Collapse
Affiliation(s)
- Leos Cmarko
- Institute of Biology and Medical Genetics, First faculty of Medicine, Charles University, Prague, Czech Republic.,Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Norbert Weiss
- Institute of Biology and Medical Genetics, First faculty of Medicine, Charles University, Prague, Czech Republic. .,Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.
| |
Collapse
|
5
|
Jurkovicova-Tarabova B, Cmarko L, Rehak R, Zamponi GW, Lacinova L, Weiss N. Identification of a molecular gating determinant within the carboxy terminal region of Ca v3.3 T-type channels. Mol Brain 2019; 12:34. [PMID: 30961646 PMCID: PMC6454634 DOI: 10.1186/s13041-019-0457-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 04/01/2019] [Indexed: 01/02/2023] Open
Abstract
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.
Collapse
Affiliation(s)
| | - Leos Cmarko
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, 16610 Prague, Czech Republic
| | - Renata Rehak
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Gerald W. Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Lubica Lacinova
- Center of Biosciences, Institute of Molecular Physiology and Genetics, Academy of Sciences, Bratislava, Slovakia
| | - Norbert Weiss
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, 16610 Prague, Czech Republic
| |
Collapse
|
6
|
Wang D, Ragnarsson L, Lewis RJ. T-type Calcium Channels in Health and Disease. Curr Med Chem 2018; 27:3098-3122. [PMID: 30277145 DOI: 10.2174/0929867325666181001112821] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/28/2018] [Accepted: 08/30/2018] [Indexed: 12/12/2022]
Abstract
Low Voltage-Activated (LVA) T-type calcium channels are characterized by transient current and Low Threshold Spikes (LTS) that trigger neuronal firing and oscillatory behavior. Combined with their preferential localization in dendrites and their specific "window current", T-type calcium channels are considered to be key players in signal amplification and synaptic integration. Assisted by the emerging pharmacological tools, the structural determinants of channel gating and kinetics, as well as novel physiological and pathological functions of T-type calcium channels, are being uncovered. In this review, we provide an overview of structural determinants in T-type calcium channels, their involvement in disorders and diseases, the development of novel channel modulators, as well as Structure-Activity Relationship (SAR) studies that lead to rational drug design.
Collapse
Affiliation(s)
- Dan Wang
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, the University of Queensland, Brisbane Qld 4072, Australia
| | - Lotten Ragnarsson
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, the University of Queensland, Brisbane Qld 4072, Australia
| | - Richard J Lewis
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, the University of Queensland, Brisbane Qld 4072, Australia
| |
Collapse
|
7
|
Garza-Lopez E, Lopez JA, Hagen J, Sheffer R, Meiner V, Lee A. Role of a conserved glutamine in the function of voltage-gated Ca 2+ channels revealed by a mutation in human CACNA1D. J Biol Chem 2018; 293:14444-14454. [PMID: 30054272 DOI: 10.1074/jbc.ra118.003681] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/24/2018] [Indexed: 12/11/2022] Open
Abstract
Voltage-gated Cav Ca2+ channels play crucial roles in regulating gene transcription, neuronal excitability, and synaptic transmission. Natural or pathological variations in Cav channels have yielded rich insights into the molecular determinants controlling channel function. Here, we report the consequences of a natural, putatively disease-associated mutation in the CACNA1D gene encoding the pore-forming Cav1.3 α1 subunit. The mutation causes a substitution of a glutamine residue that is highly conserved in the extracellular S1-S2 loop of domain II in all Cav channels with a histidine and was identified by whole-exome sequencing of an individual with moderate hearing impairment, developmental delay, and epilepsy. When introduced into the rat Cav1.3 cDNA, Q558H significantly decreased the density of Ca2+ currents in transfected HEK293T cells. Gating current analyses and cell-surface biotinylation experiments suggested that the smaller current amplitudes caused by Q558H were because of decreased numbers of functional Cav1.3 channels at the cell surface. The substitution also produced more sustained Ca2+ currents by weakening voltage-dependent inactivation. When inserted into the corresponding locus of Cav2.1, the substitution had similar effects as in Cav1.3. However, the substitution introduced in Cav3.1 reduced current density, but had no effects on voltage-dependent inactivation. Our results reveal a critical extracellular determinant of current density for all Cav family members and of voltage-dependent inactivation of Cav1.3 and Cav2.1 channels.
Collapse
Affiliation(s)
- Edgar Garza-Lopez
- From the Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, and Neurology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242 and
| | - Josue A Lopez
- From the Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, and Neurology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242 and
| | - Jussara Hagen
- From the Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, and Neurology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242 and
| | - Ruth Sheffer
- Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Vardiella Meiner
- Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Amy Lee
- From the Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, and Neurology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242 and
| |
Collapse
|
8
|
Sanchez-Sandoval AL, Herrera Carrillo Z, Díaz Velásquez CE, Delgadillo DM, Rivera HM, Gomora JC. Contribution of S4 segments and S4-S5 linkers to the low-voltage activation properties of T-type CaV3.3 channels. PLoS One 2018; 13:e0193490. [PMID: 29474447 PMCID: PMC5825144 DOI: 10.1371/journal.pone.0193490] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 02/12/2018] [Indexed: 11/25/2022] Open
Abstract
Voltage-gated calcium channels contain four highly conserved transmembrane helices known as S4 segments that exhibit a positively charged residue every third position, and play the role of voltage sensing. Nonetheless, the activation range between high-voltage (HVA) and low-voltage (LVA) activated calcium channels is around 30–40 mV apart, despite the high level of amino acid similarity within their S4 segments. To investigate the contribution of S4 voltage sensors for the low-voltage activation characteristics of CaV3.3 channels we constructed chimeras by swapping S4 segments between this LVA channel and the HVA CaV1.2 channel. The substitution of S4 segment of Domain II in CaV3.3 by that of CaV1.2 (chimera IIS4C) induced a ~35 mV shift in the voltage-dependence of activation towards positive potentials, showing an I-V curve that almost overlaps with that of CaV1.2 channel. This HVA behavior induced by IIS4C chimera was accompanied by a 2-fold decrease in the voltage-dependence of channel gating. The IVS4 segment had also a strong effect in the voltage sensing of activation, while substitution of segments IS4 and IIIS4 moved the activation curve of CaV3.3 to more negative potentials. Swapping of IIS4 voltage sensor influenced additional properties of this channel such as steady-state inactivation, current decay, and deactivation. Notably, Domain I voltage sensor played a major role in preventing CaV3.3 channels to inactivate from closed states at extreme hyperpolarized potentials. Finally, site-directed mutagenesis in the CaV3.3 channel revealed a partial contribution of the S4-S5 linker of Domain II to LVA behavior, with synergic effects observed in double and triple mutations. These findings indicate that IIS4 and, to a lesser degree IVS4, voltage sensors are crucial in determining the LVA properties of CaV3.3 channels, although the accomplishment of this function involves the participation of other structural elements like S4-S5 linkers.
Collapse
Affiliation(s)
- Ana Laura Sanchez-Sandoval
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México Mexico City, México
| | - Zazil Herrera Carrillo
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México Mexico City, México
| | - Clara Estela Díaz Velásquez
- Programa de Neurociencias, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla de Baz, Estado de México, México
| | - Dulce María Delgadillo
- Laboratorios Nacionales de Servicios Experimentales Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, México
| | - Heriberto Manuel Rivera
- Facultad de Medicina, Universidad Autónoma del Estado de Morelos Cuernavaca, Morelos, México
| | - Juan Carlos Gomora
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México Mexico City, México
- * E-mail:
| |
Collapse
|
9
|
Tuluc P, Yarov-Yarovoy V, Benedetti B, Flucher BE. Molecular Interactions in the Voltage Sensor Controlling Gating Properties of CaV Calcium Channels. Structure 2015; 24:261-71. [PMID: 26749449 DOI: 10.1016/j.str.2015.11.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 12/17/2022]
Abstract
Voltage-gated calcium channels (CaV) regulate numerous vital functions in nerve and muscle cells. To fulfill their diverse functions, the multiple members of the CaV channel family are activated over a wide range of voltages. Voltage sensing in potassium and sodium channels involves the sequential transition of positively charged amino acids across a ring of residues comprising the charge transfer center. In CaV channels, the precise molecular mechanism underlying voltage sensing remains elusive. Here we combined Rosetta structural modeling with site-directed mutagenesis to identify the molecular mechanism responsible for the specific gating properties of two CaV1.1 splice variants. Our data reveal previously unnoticed interactions of S4 arginines with an aspartate (D1196) outside the charge transfer center of the fourth voltage-sensing domain that are regulated by alternative splicing of the S3-S4 linker. These interactions facilitate the final transition into the activated state and critically determine the voltage sensitivity and current amplitude of these CaV channels.
Collapse
Affiliation(s)
- Petronel Tuluc
- Department of Physiology and Medical Physics, Medical University Innsbruck, Fritz-Pregl-Strasse 3, A-6020 Innsbruck, Austria; Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria.
| | | | - Bruno Benedetti
- Department of Physiology and Medical Physics, Medical University Innsbruck, Fritz-Pregl-Strasse 3, A-6020 Innsbruck, Austria
| | - Bernhard E Flucher
- Department of Physiology and Medical Physics, Medical University Innsbruck, Fritz-Pregl-Strasse 3, A-6020 Innsbruck, Austria.
| |
Collapse
|
10
|
Coutelier M, Blesneac I, Monteil A, Monin ML, Ando K, Mundwiller E, Brusco A, Le Ber I, Anheim M, Castrioto A, Duyckaerts C, Brice A, Durr A, Lory P, Stevanin G. A Recurrent Mutation in CACNA1G Alters Cav3.1 T-Type Calcium-Channel Conduction and Causes Autosomal-Dominant Cerebellar Ataxia. Am J Hum Genet 2015; 97:726-37. [PMID: 26456284 DOI: 10.1016/j.ajhg.2015.09.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 09/18/2015] [Indexed: 12/20/2022] Open
Abstract
Hereditary cerebellar ataxias (CAs) are neurodegenerative disorders clinically characterized by a cerebellar syndrome, often accompanied by other neurological or non-neurological signs. All transmission modes have been described. In autosomal-dominant CA (ADCA), mutations in more than 30 genes are implicated, but the molecular diagnosis remains unknown in about 40% of cases. Implication of ion channels has long been an ongoing topic in the genetics of CA, and mutations in several channel genes have been recently connected to ADCA. In a large family affected by ADCA and mild pyramidal signs, we searched for the causative variant by combining linkage analysis and whole-exome sequencing. In CACNA1G, we identified a c.5144G>A mutation, causing an arginine-to-histidine (p.Arg1715His) change in the voltage sensor S4 segment of the T-type channel protein Cav3.1. Two out of 479 index subjects screened subsequently harbored the same mutation. We performed electrophysiological experiments in HEK293T cells to compare the properties of the p.Arg1715His and wild-type Cav3.1 channels. The current-voltage and the steady-state activation curves of the p.Arg1715His channel were shifted positively, whereas the inactivation curve had a higher slope factor. Computer modeling in deep cerebellar nuclei (DCN) neurons suggested that the mutation results in decreased neuronal excitability. Taken together, these data establish CACNA1G, which is highly expressed in the cerebellum, as a gene whose mutations can cause ADCA. This is consistent with the neuropathological examination, which showed severe Purkinje cell loss. Our study further extends our knowledge of the link between calcium channelopathies and CAs.
Collapse
|
11
|
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; 467:2519-27. [PMID: 26306541 DOI: 10.1007/s00424-015-1728-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 08/16/2015] [Accepted: 08/18/2015] [Indexed: 01/23/2023]
Abstract
Low-voltage-activated CaV3 channels are distinguished among other voltage-activated calcium channels by the most negative voltage activation threshold. The voltage dependence of current activation is virtually identical in all three CaV3 channels while the current kinetics of the CaV3.3 current is one order slower than that of the CaV3.1 and CaV3.2 channels. We have analyzed the voltage dependence and kinetics of charge (Q) movement in human recombinant CaV3.3 and CaV3.1 channels. The voltage dependence of voltage sensor activation (Qon-V) of the CaV3.3 channel was significantly shifted with respect to that of the CaV3.1 channel by +18.6 mV and the kinetic of Qon activation in the CaV3.3 channel was significantly slower than that of the CaV3.1 channel. Removal of the gating brake in the intracellular loop connecting repeats I and II in the CaV3.3 channel in the ID12 mutant channel shifted the Qon-V relation to a value even more negative than that for the CaV3.1 channel. The kinetic of Qon activation was not significantly different between ID12 and CaV3.1 channels. Deletion of the gating brake in the CaV3.1 channel resulted in a GD12 channel with the voltage dependence of the gating current activation significantly shifted toward more negative potentials. The Qon kinetic was not significantly altered. ID12 and GD12 mutants did not differ significantly in voltage dependence nor in the kinetic of voltage sensor activation. In conclusion, the putative gating brake in the intracellular loop connecting repeats I and II controls the gating current of the CaV3 channels. We suggest that activation of the voltage sensor in domain I is limiting both the voltage dependence and the kinetics of CaV3 channel activation.
Collapse
Affiliation(s)
- Mária Karmažínová
- Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlarska 5, 833 34, Bratislava, Slovakia
| | - Katarína Jašková
- Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlarska 5, 833 34, Bratislava, Slovakia
| | - Peter Griac
- Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Ivanka pri Dunaji, Slovakia
| | - Edward Perez-Reyes
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908, USA
| | - Ľubica Lacinová
- Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlarska 5, 833 34, Bratislava, Slovakia.
| |
Collapse
|
12
|
Simms BA, Zamponi GW. Neuronal voltage-gated calcium channels: structure, function, and dysfunction. Neuron 2014; 82:24-45. [PMID: 24698266 DOI: 10.1016/j.neuron.2014.03.016] [Citation(s) in RCA: 396] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Voltage-gated calcium channels are the primary mediators of depolarization-induced calcium entry into neurons. There is great diversity of calcium channel subtypes due to multiple genes that encode calcium channel α1 subunits, coassembly with a variety of ancillary calcium channel subunits, and alternative splicing. This allows these channels to fulfill highly specialized roles in specific neuronal subtypes and at particular subcellular loci. While calcium channels are of critical importance to brain function, their inappropriate expression or dysfunction gives rise to a variety of neurological disorders, including, pain, epilepsy, migraine, and ataxia. This Review discusses salient aspects of voltage-gated calcium channel function, physiology, and pathophysiology.
Collapse
Affiliation(s)
- Brett A Simms
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.
| |
Collapse
|
13
|
Bladen C, Hamid J, Souza IA, Zamponi GW. Block of T-type calcium channels by protoxins I and II. Mol Brain 2014; 7:36. [PMID: 24886690 PMCID: PMC4030284 DOI: 10.1186/1756-6606-7-36] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/05/2014] [Indexed: 01/08/2023] Open
Abstract
Background Low-voltage-activated (T-type) calcium channels play a crucial role in a number of physiological processes, including neuronal and cardiac pacemaker activity and nociception. Therefore, finding specific modulators and/or blockers of T-type channels has become an important field of drug discovery. One characteristic of T-type calcium channels is that they share several structural similarities with voltage-gated sodium channels (VGSCs). We therefore hypothesized that binding sites for certain sodium channel blocking peptide toxins may be present in T-type calcium channels. Findings The sodium channel blocker ProTx I tonically blocked native and transiently expressed T-type channels in the sub- to low micro molar range with at least a ten-fold selectivity for the T-type calcium channel hCav3.1 over hCav3.3, and more than one hundred fold selectivity over hCav3.2. Using chimeras of hCav3.1 and hCav3.3, we determined that the domain IV region of hCav3.1 is a major determinant of toxin affinity, with a minor contribution from domain II. Further analysis revealed several residues in a highly conserved region between T-type and sodium channels that may correspond to toxin binding sites. Mutagenesis of several of these residues on an individual basis, however, did not alter the blocking effects of the toxin. ProTx II on the other hand preferentially blocked hCav3.2 and significantly shifted the steady state inactivation of this channel. Conclusions ProTx I blocks hCav3.1 both selectively and with high affinity. Domain IV appears to play a major role in this selectivity with some contribution from domain II. Given the structural similarities between sodium and T-type calcium channels and the apparent conservation in toxin binding sites, these data could provide insights into the development and synthesis of novel T-type channel antagonists.
Collapse
Affiliation(s)
| | | | | | - Gerald W Zamponi
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, NW, Canada.
| |
Collapse
|
14
|
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; 461:461-8. [PMID: 21340458 DOI: 10.1007/s00424-011-0937-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 02/06/2011] [Accepted: 02/08/2011] [Indexed: 01/10/2023]
Abstract
Low-voltage-activated Ca(v)3 Ca(2+) channels have an activation threshold around -60 mV, which is lower than the activation threshold of other voltage-dependent calcium channels (VDCCs). The kinetics of their activation at membrane voltages just above the activation threshold is much slower than the activation kinetics of other VDCCs. It was demonstrated recently that the intracellular loop connecting repeats I and II of all three Ca(v)3 channels contains a so-called gating brake. Disruption of this brake yields channels that activate at even more hyperpolarized potentials with significantly accelerated kinetics. We have compared gating of a wild-type Ca(v)3.3 channel and a mutated ID12 channel, in which the putative gating brake at the proximal part of the I-II loop was removed. Voltage dependence of the gating current activation was shifted by 34.6 mV towards more hyperpolarized potentials in ID12 channel. ON-charge movement was significantly faster in the ID12 channel, while the kinetics of the off-charge was not altered by the mutation. We conclude that the putative gating brake in I-II loop hinders not only the opening of the conducting pore but also the activating movement of voltage-sensing S4 segments, stabilizing the channel in its closed state.
Collapse
Affiliation(s)
- Mária Karmažínová
- Institute of Molecular Physiology and Genetics, Centre of Excellence for Cardiovascular Research, Slovak Academy of Sciences, Bratislava, Slovakia
| | | | | | | |
Collapse
|
15
|
Tadayonnejad R, Anderson D, Molineux ML, Mehaffey WH, Jayasuriya K, Turner RW. Rebound discharge in deep cerebellar nuclear neurons in vitro. THE CEREBELLUM 2011; 9:352-74. [PMID: 20396983 PMCID: PMC2949560 DOI: 10.1007/s12311-010-0168-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Neurons of the deep cerebellar nuclei (DCN) play a critical role in defining the output of cerebellum in the course of encoding Purkinje cell inhibitory inputs. The earliest work performed with in vitro preparations established that DCN cells have the capacity to translate membrane hyperpolarizations into a rebound increase in firing frequency. The primary means of distinguishing between DCN neurons has been according to cell size and transmitter phenotype, but in some cases, differences in the firing properties of DCN cells maintained in vitro have been reported. In particular, it was shown that large diameter cells in the rat DCN exhibit two phenotypes of rebound discharge in vitro that may eventually help define their functional roles in cerebellar output. A transient burst and weak burst phenotype can be distinguished based on the frequency and pattern of rebound discharge immediately following a hyperpolarizing stimulus. Work to date indicates that the difference in excitability arises from at least the degree of activation of T-type Ca(2+) current during the immediate phase of rebound firing and Ca(2+)-dependent K(+) channels that underlie afterhyperpolarizations. Both phenotypes can be detected following stimulation of Purkinje cell inhibitory inputs under conditions that preserve resting membrane potential and natural ionic gradients. In this paper, we review the evidence supporting the existence of different rebound phenotypes in DCN cells and the ion channel expression patterns that underlie their generation.
Collapse
Affiliation(s)
- Reza Tadayonnejad
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta Canada T2N 4N1
| | - Dustin Anderson
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta Canada T2N 4N1
| | - Michael L. Molineux
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta Canada T2N 4N1
| | - W. Hamish Mehaffey
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta Canada T2N 4N1
| | - Kusala Jayasuriya
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta Canada T2N 4N1
| | - Ray W. Turner
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta Canada T2N 4N1
- Hotchkiss Brain Institute, HRIC 1AA14, University of Calgary, 3330 Hospital Dr. N.W., Calgary, Alberta Canada T2N 4N1
| |
Collapse
|
16
|
Karmazinova M, Beyl S, Stary-Weinzinger A, Suwattanasophon C, Klugbauer N, Hering S, Lacinova L. Cysteines in the loop between IS5 and the pore helix of CaV3.1 are essential for channel gating. Pflugers Arch 2010; 460:1015-28. [DOI: 10.1007/s00424-010-0874-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 08/09/2010] [Accepted: 08/17/2010] [Indexed: 11/28/2022]
|
17
|
Anderson D, Mehaffey WH, Iftinca M, Rehak R, Engbers JDT, Hameed S, Zamponi GW, Turner RW. Regulation of neuronal activity by Cav3-Kv4 channel signaling complexes. Nat Neurosci 2010; 13:333-7. [PMID: 20154682 DOI: 10.1038/nn.2493] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 12/14/2009] [Indexed: 11/09/2022]
Abstract
Kv4 low voltage-activated A-type potassium channels are widely expressed in excitable cells, where they control action potential firing, dendritic activity and synaptic integration. Kv4 channels exist as a complex that includes K(+) channel-interacting proteins (KChIPs), which contain calcium-binding domains and therefore have the potential to confer calcium dependence on the Kv4 channel. We found that T-type calcium channels and Kv4 channels form a signaling complex in rat that efficiently couples calcium influx to KChIP3 to modulate Kv4 function. This interaction was critical for allowing Kv4 channels to function in the subthreshold membrane potential range to regulate neuronal firing properties. The widespread expression of these channels and accessory proteins indicates that the Cav3-Kv4 signaling complex is important for the function of a wide range of electrically excitable cells.
Collapse
Affiliation(s)
- Dustin Anderson
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Aromolaran KA, Benzow KA, Cribbs LL, Koob MD, Piedras-Rentería ES. T-type current modulation by the actin-binding protein Kelch-like 1. Am J Physiol Cell Physiol 2010; 298:C1353-62. [PMID: 20147652 DOI: 10.1152/ajpcell.00235.2009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We report a novel form of modulation of T-type calcium currents carried out by the neuronal actin-binding protein (ABP) Kelch-like 1 (KLHL1). KLHL1 is a constitutive neuronal ABP localized to the soma and dendritic arbors; its genetic elimination in Purkinje neurons leads to dendritic atrophy and motor insufficiency. KLHL1 participates in neurite outgrowth and upregulates voltage-gated P/Q-type calcium channel function; here we investigated KLHL1's role as a modulator of low-voltage-gated calcium channels and determined the molecular mechanism of this modulation with electrophysiology and biochemistry. Coexpression of KLHL1 with Ca(V)3.1 or Ca(V)3.2 (alpha(1G) or alpha(1H) subunits) caused increases in T-type current density (35%) and calcium influx (75-83%) when carried out by alpha(1H) but not by alpha(1G). The association between KLHL1 and alpha(1H) was determined by immunoprecipitation and immunolocalization in brain membrane fractions and in vitro in HEK-293 cells. Noise analysis showed that neither alpha(1H) single-channel conductance nor open probability was altered by KLHL1, yet a significant increase in channel number was detected and further corroborated by Western blot analysis. KLHL1 also induced an increase in alpha(1H) current deactivation time (tau(deactivation)). Interestingly, the majority of KLHL1's effects were eliminated when the actin-binding motif (kelch) was removed, with the exception of the calcium influx increase during action potentials, indicating that KLHL1 interacts with alpha(1H) and actin and selectively regulates alpha(1H) function by increasing the number of alpha(1H) channels. This constitutes a novel regulatory mechanism of T-type calcium currents and supports the role of KLHL1 in the modulation of cellular excitability.
Collapse
|
19
|
Kang HW, Park JY, Lee JH. Distinct contributions of different structural regions to the current kinetics of the Cav3.3 T-type Ca2+ channel. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:2740-8. [DOI: 10.1016/j.bbamem.2008.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Revised: 08/04/2008] [Accepted: 08/04/2008] [Indexed: 10/21/2022]
|
20
|
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. [PMID: 18714336 PMCID: PMC2495038 DOI: 10.1371/journal.pone.0002976] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 07/26/2008] [Indexed: 11/25/2022] Open
Abstract
The intracellular loops that interlink the four transmembrane domains of Ca2+- and Na+-channels (Cav, Nav) have critical roles in numerous forms of channel regulation. In particular, the intracellular loop that joins repeats I and II (I–II loop) in high voltage-activated (HVA) Ca2+ channels possesses the binding site for Cavβ subunits and plays significant roles in channel function, including trafficking the α1 subunits of HVA channels to the plasma membrane and channel gating. Although there is considerable divergence in the primary sequence of the I–II loop of Cav1/Cav2 HVA channels and Cav3 LVA/T-type channels, evidence for a regulatory role of the I–II loop in T-channel function has recently emerged for Cav3.2 channels. In order to provide a comprehensive view of the role this intracellular region may play in the gating and surface expression in Cav3 channels, we have performed a structure-function analysis of the I–II loop in Cav3.1 and Cav3.3 channels using selective deletion mutants. Here we show the first 60 amino acids of the loop (post IS6) are involved in Cav3.1 and Cav3.3 channel gating and kinetics, which establishes a conserved property of this locus for all Cav3 channels. In contrast to findings in Cav3.2, deletion of the central region of the I–II loop in Cav3.1 and Cav3.3 yielded a modest increase (+30%) and a reduction (−30%) in current density and surface expression, respectively. These experiments enrich our understanding of the structural determinants involved in Cav3 function by highlighting the unique role played by the intracellular I–II loop in Cav3.2 channel trafficking, and illustrating the prominent role of the gating brake in setting the slow and distinctive slow activation kinetics of Cav3.3.
Collapse
Affiliation(s)
- Joel P Baumgart
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, United States of America
| | | | | | | | | | | |
Collapse
|
21
|
Hering S, Beyl S, Stary A, Kudrnac M, Hohaus A, Guy HR, Timin E. Pore stability and gating in voltage-activated calcium channels. Channels (Austin) 2008; 2:61-9. [PMID: 18849656 DOI: 10.4161/chan.2.2.5999] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Calcium channel family members activate at different membrane potentials, which enables tissue specific calcium entry. Pore mutations affecting this voltage dependence are associated with channelopathies. In this review we analyze the link between voltage sensitivity and corresponding kinetic phenotypes of calcium channel activation. Systematic changes in hydrophobicity in the lower third of S6 segments gradually shift the activation curve thereby determining the voltage sensitivity. Homology modeling suggests that hydrophobic residues that are located in all four S6 segments close to the inner channel mouth might form adhesion points stabilizing the closed gate. Simulation studies support a scenario where voltage sensors and the pore are essentially independent structural units. We speculate that evolution designed the voltage sensing machinery as robust "all-or-non" device while the varietys of voltage sensitivities of different channel types was accomplished by shaping pore stability.
Collapse
Affiliation(s)
- Steffen Hering
- Institute of Pharmacology and Toxicology, University of Vienna, Vienna, Austria.
| | | | | | | | | | | | | |
Collapse
|
22
|
Hildebrand ME, David LS, Hamid J, Mulatz K, Garcia E, Zamponi GW, Snutch TP. Selective Inhibition of Cav3.3 T-type Calcium Channels by Gαq/11-coupled Muscarinic Acetylcholine Receptors. J Biol Chem 2007; 282:21043-55. [PMID: 17535809 DOI: 10.1074/jbc.m611809200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
T-type calcium channels play critical roles in controlling neuronal excitability, including the generation of complex spiking patterns and the modulation of synaptic plasticity, although the mechanisms and extent to which T-type Ca(2+) channels are modulated by G-protein-coupled receptors (GPCRs) remain largely unexplored. To examine specific interactions between T-type Ca(2+) channel subtypes and muscarinic acetylcholine receptors (mAChRS), the Cav3.1 (alpha(1G)), Cav3.2 (alpha(1H)), and Cav3.3 (alpha) T-type Ca(2+)(1I)channels were co-expressed with the M1 Galpha(q/11)-coupled mAChR. Perforated patch recordings demonstrate that activation of M1 receptors has a strong inhibitory effect on Cav3.3 T-type Ca(2+) currents but either no effect or a moderate stimulating effect on Cav3.1 and Cav3.2 peak current amplitudes. This differential modulation was observed for both rat and human T-type Ca(2+) channel variants. The inhibition of Cav3.3 channels by M1 receptors is reversible, use-independent, and associated with a concomitant increase in inactivation kinetics. Loss-of-function experiments with genetically encoded antagonists of Galpha and Gbetagamma proteins and gain-of-function experiments with genetically encoded Galpha subtypes indicate that M1 receptor-mediated inhibition of Cav3.3 occurs through Galpha(q/11). This is supported by experiments showing that activation of the M3 and M5 Galpha(q/11)-coupled mAChRs also causes inhibition of Cav3.3 currents, although Galpha(i)-coupled mAChRs (M2 and M4) have no effect. Examining Cav3.1-Cav3.3 chimeric channels demonstrates that two distinct regions of the Cav3.3 channel are necessary and sufficient for complete M1 receptor-mediated channel inhibition and represent novel sites not previously implicated in T-type channel modulation.
Collapse
Affiliation(s)
- Michael E Hildebrand
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4
| | | | | | | | | | | | | |
Collapse
|