總結(jié) |
Voltage-dependent Ca2+ channels are a family of membrane proteins that allow cells to couple electrical activity to intracellular Ca2+ signaling1. Voltage-gated Ca2+ 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, voltage-gated Ca2+ subtypes can be further divided into two broad groups: the low (T-type) and high (L, N, P, Q and R-type) threshold-activated channels2. The activity of the channel pore is modulated by 4 tightly-coupled subunits: an intracellular β subunit; a transmembrane γ subunit; and a disulphide-linked complex of α2 and δ subunits3. There are four distinct β subunits: β1, β2, β3 and β44. There are 4 splice variants of the β2 subunit: β2a, β2b, β2c and β2d. β2a and β2b are expressed in heart, aorta and brain, and are 606- and 632-residue proteins, respectively. β2c and β2d (655 and 604 residues, respectively) are expressed in brain, and recent studies show beta-2c to be also expressed in heart. All splice variants differ in their N-terminal regions5.
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別名 |
Voltage-dependent L-type calcium channel subunit beta-2, CAB2, Calcium channel voltage-dependent subunit beta 2, Cacnb2, Cacnlb2
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