Protein Domain : IPR005421

Type:  Family Name:  Voltage-dependent calcium channel, gamma-1 subunit
Description:  Ca2+ ions are unique in that they not only carry charge but they are also the most widely used of diffusible second messengers. Voltage-dependent Ca2+ channels (VDCC) are a family of molecules that allow cells to couple electrical activity to intracellular Ca2+ signalling. The opening and closing of these channels by depolarizing stimuli, such as action potentials, allows Ca2+ ions to enter neurons down a steep electrochemical gradient, producing transient intracellular Ca2+ signals. Many of the processes that occur in neurons, including transmitter release, gene transcription and metabolism are controlled by Ca2+ influx occurring simultaneously at different cellular locales. The pore is formed by the alpha-1 subunit which incorporates the conduction pore, the voltage sensor and gating apparatus, and the known sites of channel regulation by second messengers, drugs, and toxins []. The activity of this pore is modulated by 4 tightly-coupled subunits: an intracellular beta subunit; a transmembrane gamma subunit; and a disulphide-linked complex of alpha-2 and delta subunits, which are proteolytically cleaved from the same gene product. Properties of the protein including gating voltage-dependence, G protein modulation and kinase susceptibility can be influenced by these subunits.Voltage-gated calcium channels are classified as T, L, N, P, Q and R, and are distinguished by their sensitivity to pharmacological blocks, single-channel conductance kinetics, and voltage-dependence. On the basis of their voltage activation properties, the voltage-gated calcium classes can be further divided into two broad groups: the low (T-type) and high (L, N, P, Q and R-type) threshold-activated channels.The voltage-dependent calcium channel gamma (VDCCG) subunit family consists of at least 8 members, which share a number of common structural features[]. Each member is predicted to possess 4 transmembrane domains, with intracellular N- and C-termini. The first extracellular loop contains a highly conserved N-glycosylation site and a pair of conserved cysteine residues. The C-terminal 7 residues of VDCCG-2, -3, -4 and -8 are also conserved andcontain a consensus site for phosphorylation by cAMP and cGMP-dependent protein kinases, and a target site for binding by PDZ domain proteins [].The VDCCG-1 subunit is a 25kDa protein expressed exclusively in skeletal muscle cells, where it functions as a dihydropyridine-sensitive, L-type calcium channel subunit []. The modulatory properties of VDCCG-1 subunits have been investigated using heterologous expression systems. Coexpressionof VDCCG-1 subunits with L-type or P/Q-type channels induces moderate changes in activation and inactivation properties, and modification of thepeak current amplitude of these channels [, ]. Short Name:  VDCC_g1su

0 Child Features

0 Contains

1 Cross References

Identifier
PR01601

0 Found In

3 GO Annotations

GO Term Gene Name
GO:0005245 IPR005421
GO:0070588 IPR005421
GO:0005891 IPR005421

3 Ontology Annotations

GO Term Gene Name
GO:0005245 IPR005421
GO:0070588 IPR005421
GO:0005891 IPR005421

1 Parent Features

DB identifier Type Name
IPR008368 Family Voltage-dependent calcium channel, gamma subunit

0 Proteins

5 Publications

First Author Title Year Journal Volume Pages PubMed ID
            14657414
            11170751
            2158672
            1718988
            1716787