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Voltage gated Ca(2+) channel (VGCC) auxiliary beta subunits increase membrane expression of the main pore-forming alpha(1) subunits and finely tune channel activation and inactivation properties. In expression studies, co-expression of beta subunits also reduced neuronal Ca(2+) channel regulation by heterotrimeric G protein. Biochemical studies suggest that VGCC beta subunits and G protein betagamma can compete for overlapping interaction sites on VGCC alpha(1) subunits, suggesting a dynamic association of these subunits with alpha(1). In this work we have analyzed the stability of the alpha(1)/beta association under physiological conditions. Regulation of the alpha(1A) Ca(2+) channel inactivation properties by beta(1b) and beta(2a) subunits had two major effects: a shift in voltage-dependent inactivation (E(in)), and an increase of the non-inactivating current (R(in)). Unexpectedly, large variations in magnitude of the effects were recorded on E(in), when beta(1b) was expressed, and R(in), when beta(2a) was expressed. These variations were not proportional to the current amplitude, and occurred at similar levels of beta subunit expression. beta(2a)-induced variations of R(in) were, however, inversely proportional to the magnitude of G protein block. These data underline the two different mechanisms used by beta(1b) and beta(2a) to regulate channel inactivation, and suggest that the VGCC beta subunit can unbind the alpha1 subunit in physiological situations.
Bichet,
Reversibility of the Ca(2+) channel alpha(1)-beta subunit interaction.
2000, Pubmed
Bichet,
Reversibility of the Ca(2+) channel alpha(1)-beta subunit interaction.
2000,
Pubmed
Birnbaumer,
Structures and functions of calcium channel beta subunits.
1998,
Pubmed
,
Xenbase
Bourinet,
Determinants of the G protein-dependent opioid modulation of neuronal calcium channels.
1996,
Pubmed
,
Xenbase
Cahill,
Coexpression of cloned alpha(1B), beta(2a), and alpha(2)/delta subunits produces non-inactivating calcium currents similar to those found in bovine chromaffin cells.
2000,
Pubmed
,
Xenbase
Cens,
Promotion and inhibition of L-type Ca2+ channel facilitation by distinct domains of the subunit.
1998,
Pubmed
,
Xenbase
Cens,
Voltage and calcium use the same molecular determinants to inactivate calcium channels.
1999,
Pubmed
Cens,
Coexpression of the beta2 subunit does not induce voltage-dependent facilitation of the class C L-type Ca channel.
1996,
Pubmed
,
Xenbase
Chien,
Membrane targeting of L-type calcium channels. Role of palmitoylation in the subcellular localization of the beta2a subunit.
1998,
Pubmed
Chien,
Identification of palmitoylation sites within the L-type calcium channel beta2a subunit and effects on channel function.
1996,
Pubmed
De Waard,
Ca2+ channel regulation by a conserved beta subunit domain.
1994,
Pubmed
,
Xenbase
De Waard,
Properties of the alpha 1-beta anchoring site in voltage-dependent Ca2+ channels.
1995,
Pubmed
,
Xenbase
De Waard,
Subunit regulation of the neuronal alpha 1A Ca2+ channel expressed in Xenopus oocytes.
1995,
Pubmed
,
Xenbase
De Waard,
Identification of critical amino acids involved in alpha1-beta interaction in voltage-dependent Ca2+ channels.
1996,
Pubmed
,
Xenbase
De Waard,
Direct binding of G-protein betagamma complex to voltage-dependent calcium channels.
1997,
Pubmed
,
Xenbase
Gao,
Complexes of the alpha1C and beta subunits generate the necessary signal for membrane targeting of class C L-type calcium channels.
1999,
Pubmed
Gerster,
Current modulation and membrane targeting of the calcium channel alpha1C subunit are independent functions of the beta subunit.
1999,
Pubmed
Hurley,
The role of dynamic palmitoylation in Ca2+ channel inactivation.
2000,
Pubmed
Jones,
Mechanism of auxiliary subunit modulation of neuronal alpha1E calcium channels.
1998,
Pubmed
Mangoni,
Characterisation of alpha 1A Ba2+, Sr2+ and Ca2+ currents recorded with the ancillary beta 1-4 subunits.
1997,
Pubmed
,
Xenbase
Olcese,
The amino terminus of a calcium channel beta subunit sets rates of channel inactivation independently of the subunit's effect on activation.
1994,
Pubmed
,
Xenbase
Perez-Reyes,
Cloning and expression of a cardiac/brain beta subunit of the L-type calcium channel.
1992,
Pubmed
,
Xenbase
Pragnell,
Cloning and tissue-specific expression of the brain calcium channel beta-subunit.
1991,
Pubmed
Pragnell,
Calcium channel beta-subunit binds to a conserved motif in the I-II cytoplasmic linker of the alpha 1-subunit.
1994,
Pubmed
Qin,
Unique regulatory properties of the type 2a Ca2+ channel beta subunit caused by palmitoylation.
1998,
Pubmed
,
Xenbase
Qin,
Identification of a second region of the beta-subunit involved in regulation of calcium channel inactivation.
1996,
Pubmed
,
Xenbase
Restituito,
The [beta]2a subunit is a molecular groom for the Ca2+ channel inactivation gate.
2000,
Pubmed
,
Xenbase
Sather,
Distinctive biophysical and pharmacological properties of class A (BI) calcium channel alpha 1 subunits.
1993,
Pubmed
,
Xenbase
Starr,
Primary structure of a calcium channel that is highly expressed in the rat cerebellum.
1991,
Pubmed
Stea,
Localization and functional properties of a rat brain alpha 1A calcium channel reflect similarities to neuronal Q- and P-type channels.
1994,
Pubmed
,
Xenbase
Tareilus,
A Xenopus oocyte beta subunit: evidence for a role in the assembly/expression of voltage-gated calcium channels that is separate from its role as a regulatory subunit.
1997,
Pubmed
,
Xenbase
Vance,
Differential expression and association of calcium channel alpha1B and beta subunits during rat brain ontogeny.
1998,
Pubmed
Walker,
A beta 4 isoform-specific interaction site in the carboxyl-terminal region of the voltage-dependent Ca2+ channel alpha 1A subunit.
1998,
Pubmed
Walker,
Subunit interaction sites in voltage-dependent Ca2+ channels: role in channel function.
1998,
Pubmed
Zamponi,
Crosstalk between G proteins and protein kinase C mediated by the calcium channel alpha1 subunit.
1997,
Pubmed
,
Xenbase
