Cavβ3
Description: calcium channel, voltage-dependent, beta 3 subunit Gene: cacnb3 Alias: cacnb3
Voltage dependent calcium channels (VDCC) auxiliary beta (Cavb1–4) and alpha2delta (Cava2d1–4) subunits associate with the alpha1 functional subunits (for review see Walker and De Waard, 1998 [1279]) and affect the biophysical properties of the alpha1 subunits as observed for the auxiliary subunits of voltage-dependent sodium and potassium channels (for review see Isom et al., 1994 [1247]; Trimmer, 1998 [1280]).
CACNB3 (also known as CAB3; CACNLB3; FLJ58949) encodes beta 3 subunit of voltage dependent calcium channels.
http://www.ncbi.nlm.nih.gov/gene/784
Transcript
Species | NCBI accession | Length (nt) | |
---|---|---|---|
Human | NM_000725.4 | 2931 | |
Mouse | NM_007581.3 | 2822 | |
Rat | NM_012828.3 | 2521 |
Protein Isoforms
Isoforms
Post-Translational Modifications
High-voltage–activated calcium channels are comprised of a pore-forming alpha1 subunit, auxiliary beta and alpha2delta subunits, and, in some cases, an auxiliary gamma subunit (for review see Catterall, 2000 [477]).
The b subunit has been shown to interact with alpha1 subunit interaction domain (AID) in the cytoplasmic I-II linker of alpha1 subunit (Pragnell et al., 1994 [1290]; Witcher et al., 1995 [1291]), and all four beta subunits interacted with AID of Cav2.2-alpha-1 in vitro with high affinity (Kd of 5nM; Scott et al., 1996 [1292]).
Cavβ3 predicted AlphaFold size
Methodology for AlphaFold size prediction and disclaimer are available here
It has been shown that b auxiliary subunits increase current amplitude in voltage-dependent calcium channels (Mori et al., 1991; Neely et al., 1993 [1241]; Wakamori et al., 1993 [1286]; Jones et al., 1998 [1266]; Klugbauer et al., 1999 [1289]). However, Yasuda et al. [92] found a novel inhibitory effect of b3 subunit on macroscopic Ba2+ currents through recombinant N- and R-type calcium channels expressed in Xenopus oocytes.
Coexpression of beta subunits enhanced the level of channel expression in the plasma membrane (Williams et al., 1992 [1281]; Brust et al., 1993 [1282]) by chaperoning the translocation of alpha1 subunits (Chien et al., 1995 [1261]; Yamaguchi et al., 1998 [238]; Gao et al., 1999 [1283]; Gerster et al., 1999 [1284]) from ER where beta subunits antagonize the binding between alpha1 and an ER retention protein (Bichet et al., 2000 [1285]). In addition, beta subunits also increased channel open probability without affecting single-channel conductance (Neely et al., 1993 [1221]; Wakamori et al., 1993 [1286], 1999 [1287]; Jones et al., 1998 [1266]; Gerster et al., 1999 [1284]; Hohaus et al., 2000 [1288]). A hyperpolarizing shift of I-V relationships by beta subunits (Neely et al., 1993 [1241]; Yamaguchi et al., 1998 [238]) also partially contributes to an increase in macroscopic current amplitude.
References
Yasuda T
et al.
Overexpressed Ca(v)beta3 inhibits N-type (Cav2.2) calcium channel currents through a hyperpolarizing shift of ultra-slow and closed-state inactivation.
J. Gen. Physiol.,
2004
Apr
, 123 (401-16).
Yamaguchi H
et al.
Multiple modulation pathways of calcium channel activity by a beta subunit. Direct evidence of beta subunit participation in membrane trafficking of the alpha1C subunit.
J. Biol. Chem.,
1998
Jul
24
, 273 (19348-56).
Catterall WA
Structure and regulation of voltage-gated Ca2+ channels.
Annu. Rev. Cell Dev. Biol.,
2000
, 16 (521-55).
Neely A
et al.
Potentiation by the beta subunit of the ratio of the ionic current to the charge movement in the cardiac calcium channel.
Science,
1993
Oct
22
, 262 (575-8).
Isom LL
et al.
Auxiliary subunits of voltage-gated ion channels.
Neuron,
1994
Jun
, 12 (1183-94).
Chien AJ
et al.
Roles of a membrane-localized beta subunit in the formation and targeting of functional L-type Ca2+ channels.
J. Biol. Chem.,
1995
Dec
15
, 270 (30036-44).
Jones LP
et al.
Mechanism of auxiliary subunit modulation of neuronal alpha1E calcium channels.
J. Gen. Physiol.,
1998
Aug
, 112 (125-43).
Walker D
et al.
Subunit interaction sites in voltage-dependent Ca2+ channels: role in channel function.
Trends Neurosci.,
1998
Apr
, 21 (148-54).
Trimmer JS
Regulation of ion channel expression by cytoplasmic subunits.
Curr. Opin. Neurobiol.,
1998
Jun
, 8 (370-4).
Williams ME
et al.
Structure and functional expression of an omega-conotoxin-sensitive human N-type calcium channel.
Science,
1992
Jul
17
, 257 (389-95).
Brust PF
et al.
Human neuronal voltage-dependent calcium channels: studies on subunit structure and role in channel assembly.
Neuropharmacology,
1993
Nov
, 32 (1089-102).
Gao B
et al.
Functional properties of a new voltage-dependent calcium channel alpha(2)delta auxiliary subunit gene (CACNA2D2).
J. Biol. Chem.,
2000
Apr
21
, 275 (12237-42).
Gerster U
et al.
Current modulation and membrane targeting of the calcium channel alpha1C subunit are independent functions of the beta subunit.
J. Physiol. (Lond.),
1999
Jun
1
, 517 ( Pt 2) (353-68).
Bichet D
et al.
The I-II loop of the Ca2+ channel alpha1 subunit contains an endoplasmic reticulum retention signal antagonized by the beta subunit.
Neuron,
2000
Jan
, 25 (177-90).
Wakamori M
et al.
Auxiliary subunits operate as a molecular switch in determining gating behaviour of the unitary N-type Ca2+ channel current in Xenopus oocytes.
J. Physiol. (Lond.),
1999
Jun
15
, 517 ( Pt 3) (659-72).
Wakamori M
et al.
Single-channel analysis of a cloned human heart L-type Ca2+ channel alpha 1 subunit and the effects of a cardiac beta subunit.
Biochem. Biophys. Res. Commun.,
1993
Nov
15
, 196 (1170-6).
Hohaus A
et al.
Modulation of the smooth-muscle L-type Ca2+ channel alpha1 subunit (alpha1C-b) by the beta2a subunit: a peptide which inhibits binding of beta to the I-II linker of alpha1 induces functional uncoupling.
Biochem. J.,
2000
Jun
15
, 348 Pt 3 (657-65).
Klugbauer N
et al.
Molecular diversity of the calcium channel alpha2delta subunit.
J. Neurosci.,
1999
Jan
15
, 19 (684-91).
Pragnell M
et al.
Calcium channel beta-subunit binds to a conserved motif in the I-II cytoplasmic linker of the alpha 1-subunit.
Nature,
1994
Mar
3
, 368 (67-70).
Witcher DR
et al.
Association of native Ca2+ channel beta subunits with the alpha 1 subunit interaction domain.
J. Biol. Chem.,
1995
Jul
28
, 270 (18088-93).
Scott VE
et al.
Beta subunit heterogeneity in N-type Ca2+ channels.
J. Biol. Chem.,
1996
Feb
9
, 271 (3207-12).
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