GABAB receptors inhibit low-voltage activated and high-voltage activated Ca2+ channels in sensory neurons via distinct mechanisms

Calcium (Ca2+) channels are voltage-gated ion channels present in the membrane of most excitable cells. The nomenclature for Ca2+channels was proposed by [127] and approved by the NC-IUPHAR Subcommittee on Ca2+ channels [70]. Most Ca2+ channels form hetero-oligomeric complexes. The α1 subunit is pore-forming and provides the binding site(s) for practically all agonists and antagonists. The 10 cloned α1-subunits can be grouped into three families: (1) the high-voltage activated dihydropyridine-sensitive (L-type, CaV1.x) channels; (2) the high- to moderate-voltage activated dihydropyridine-insensitive (CaV2.x) channels and (3) the low-voltage-activated (T-type, CaV3.x) channels. Each α1 subunit has four homologous repeats (I-IV), each repeat having six transmembrane domains and a pore-forming region between transmembrane domains S5 and S6. Voltage-dependent gating is driven by the membrane spanning S4 segment, which contains highly conserved positive charges that respond to changes in membrane potential. All of the α1-subunit genes give rise to alternatively spliced products. At least for high-voltage activated channels, it is likely that native channels comprise co-assemblies of α1, β and α2-δ subunits. The γ subunits have not been proven to associate with channels other than the α1s skeletal muscle Cav1.1 channel. The α2-δ1 and α2-δ2 subunits bind gabapentin and pregabalin.

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Voltage-gated calcium channels (CaV) in GtoPdb v.2021.3

IUPHAR/BPS Guide to Pharmacology CITE ◽

10.2218/gtopdb/f80/2021.3 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

William A. Catterall ◽

Edward Perez-Reyes ◽

Terrance P. Snutch ◽

Jörg Striessnig

Keyword(s):

High Voltage ◽

Low Voltage ◽

Excitable Cells ◽

Voltage Gated ◽

Voltage Dependent ◽

Alternatively Spliced ◽

Membrane Spanning ◽

Voltage Gated Ion Channels ◽

Ca2 Channels ◽

Α1 Subunit

Ca2+ channels are voltage-gated ion channels present in the membrane of most excitable cells. The nomenclature for Ca2+channels was proposed by [127] and approved by the NC-IUPHAR Subcommittee on Ca2+ channels [70]. Most Ca2+ channels form hetero-oligomeric complexes. The α1 subunit is pore-forming and provides the binding site(s) for practically all agonists and antagonists. The 10 cloned α1-subunits can be grouped into three families: (1) the high-voltage activated dihydropyridine-sensitive (L-type, CaV1.x) channels; (2) the high- to moderate-voltage activated dihydropyridine-insensitive (CaV2.x) channels and (3) the low-voltage-activated (T-type, CaV3.x) channels. Each α1 subunit has four homologous repeats (I-IV), each repeat having six transmembrane domains (S1-S6) and a pore-forming region between S5 and S6. Voltage-dependent gating is driven by the membrane spanning S4 segment, which contains highly conserved positive charges that respond to changes in membrane potential. All of the α1-subunit genes give rise to alternatively spliced products. At least for high-voltage activated channels, it is likely that native channels comprise co-assemblies of α1, β and α2-δ subunits. The γ subunits have not been proven to associate with channels other than the α1s skeletal muscle Cav1.1 channel. The α2-δ1 and α2-δ2 subunits bind gabapentin and pregabalin.

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Voltage-gated calcium channels (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

IUPHAR/BPS Guide to Pharmacology CITE ◽

10.2218/gtopdb/f80/2019.4 ◽

2019 ◽

Vol 2019 (4) ◽

Cited By ~ 1

Author(s):

William A. Catterall ◽

Edward Perez-Reyes ◽

Terrance P. Snutch ◽

Jörg Striessnig

Keyword(s):

High Voltage ◽

Low Voltage ◽

Transmembrane Domains ◽

Excitable Cells ◽

Voltage Gated ◽

Alternatively Spliced ◽

Membrane Spanning ◽

Voltage Gated Ion Channels ◽

Ca2 Channels ◽

Α1 Subunit

Calcium (Ca2+) channels are voltage-gated ion channels present in the membrane of most excitable cells. The nomenclature for Ca2+channels was proposed by [110] and approved by the NC-IUPHAR Subcommittee on Ca2+ channels [60]. Ca2+ channels form hetero-oligomeric complexes. The α1 subunit is pore-forming and provides the binding site(s) for practically all agonists and antagonists. The 10 cloned α1-subunits can be grouped into three families: (1) the high-voltage activated dihydropyridine-sensitive (L-type, CaV1.x) channels; (2) the high-voltage activated dihydropyridine-insensitive (CaV2.x) channels and (3) the low-voltage-activated (T-type, CaV3.x) channels. Each α1 subunit has four homologous repeats (I–IV), each repeat having six transmembrane domains and a pore-forming region between transmembrane domains S5 and S6. Gating is thought to be associated with the membrane-spanning S4 segment, which contains highly conserved positive charges. Many of the α1-subunit genes give rise to alternatively spliced products. At least for high-voltage activated channels, it is likely that native channels comprise co-assemblies of α1, β and α2–δ subunits. The γ subunits have not been proven to associate with channels other than the α1s skeletal muscle Cav1.1 channel. The α2–δ1 and α2–δ2 subunits bind gabapentin and pregabalin.

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The mechanism of GABAB-mediated slowing of the activation phase of high voltage-activated Ca2+ channels in rat sensory neurons

Neuroscience Letters ◽

10.1016/0304-3940(92)90567-q ◽

1992 ◽

Vol 139 (2) ◽

pp. 261-264 ◽

Cited By ~ 1

Author(s):

Hideharu Tatebayashi ◽

Nobukuni Ogata

Keyword(s):

Sensory Neurons ◽

High Voltage ◽

Ca2 Channels ◽

Activation Phase

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Voltage-gated calcium channels (version 2020.5) in the IUPHAR/BPS Guide to Pharmacology Database

IUPHAR/BPS Guide to Pharmacology CITE ◽

10.2218/gtopdb/f80/2020.5 ◽

2020 ◽

Vol 2020 (5) ◽

Cited By ~ 1

Author(s):

William A. Catterall ◽

Edward Perez-Reyes ◽

Terrance P. Snutch ◽

Jörg Striessnig

Keyword(s):

High Voltage ◽

Low Voltage ◽

Transmembrane Domains ◽

Voltage Gated ◽

Voltage Dependent ◽

Alternatively Spliced ◽

Membrane Spanning ◽

Voltage Gated Ion Channels ◽

Ca2 Channels ◽

Α1 Subunit

Calcium (Ca2+) channels are voltage-gated ion channels present in the membrane of most excitable cells. The nomenclature for Ca2+channels was proposed by [120] and approved by the NC-IUPHAR Subcommittee on Ca2+ channels [68]. Ca2+ channels form hetero-oligomeric complexes. The α1 subunit is pore-forming and provides the binding site(s) for practically all agonists and antagonists. The 10 cloned α1-subunits can be grouped into three families: (1) the high-voltage activated dihydropyridine-sensitive (L-type, CaV1.x) channels; (2) the high-voltage activated dihydropyridine-insensitive (CaV2.x) channels and (3) the low-voltage-activated (T-type, CaV3.x) channels. Each α1 subunit has four homologous repeats (I-IV), each repeat having six transmembrane domains and a pore-forming region between transmembrane domains S5 and S6. Voltage-dependent gating is driven by the membrane spanning S4 segment, which contains highly conserved positive charges that respond to changes in membrane potential. Many of the α1-subunit genes give rise to alternatively spliced products. At least for high-voltage activated channels, it is likely that native channels comprise co-assemblies of α1, β and α2-δ subunits. The γ subunits have not been proven to associate with channels other than the α1s skeletal muscle Cav1.1 channel. The α2-δ1 and α2-δ2 subunits bind gabapentin and pregabalin.

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Somatostatin modulates high-voltage-activated Ca2+ channels in freshly dissociated rat hippocampal neurons

Journal of Neurophysiology ◽

10.1152/jn.1995.74.3.1028 ◽

1995 ◽

Vol 74 (3) ◽

pp. 1028-1036 ◽

Cited By ~ 54

Author(s):

H. Ishibashi ◽

N. Akaike

Keyword(s):

High Voltage ◽

Hippocampal Neurons ◽

Pyramidal Neurons ◽

Low Voltage ◽

Inhibitory Effect ◽

Dependent Manner ◽

Ca1 Region ◽

Hippocampal Ca1 Region ◽

Hippocampal Ca1 ◽

Ca2 Channels

1. The effects of somatostatin (SS) on the low-voltage-activated and high-voltage-activated (HVA) Ca2+ channels in pyramidal neurons acutely dissociated from the hippocampal CA1 region of 2- to 3-wk-old rats were investigated in a nystatin perforated-patch recording configuration under voltage-clamp conditions. 2. SS had no effect on the low-voltage-activated Ca2+ channel but did inhibit the HVA Ca2+ channel in a concentration-, time-, and voltage-dependent manner. 3. SS showed the activation phase of Ba2+ current (IBa) passing through HVA Ca2+ channels, and the maximum inhibition was 28% of the total current amplitude measured 10 ms after the current activation. The inhibitory effect was eliminated by applying larger depolarizing prepulses. Pretreatment with pertussis toxin (PTX) completely blocked the effect of SS on HVA IBa, suggesting the contribution of PTX-sensitive Gi/Go proteins to the SS-induced inhibition. 4. The applications of forskolin, 8-Br-cAMP, dibutyryl-guanosine 3'5'-cyclic monophosphate, staurosporine, and 1-(5-isoquinolinylsulphonyl)-2-methylpiperazine did not affect either the control HVA IBa or the SS-induced inhibition of HVA IBa. 5. Pretreatment with protein kinase C (PKC) activators had no significant effect on HVA IBa but did remove the inhibition of HVA IBa by SS. 6. Omega-Conotoxin-GVIA, omega-agatoxin-IVA, nicardipine, and omega-conotoxin-MVIIC blocked HVA IBa by 27, 13, 38, and 9% of the total HVA current, respectively, which suggested the existence of N-, P-, L-, and Q-type HVA Ca2+ channels in the hippocampal CA1 pyramidal neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

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