Essential Cavβ modulatory properties are AID-independent

JM Maltez, DA Nunziato, J Kim, GS Pitt - Nature structural & molecular …, 2005 - nature.com
JM Maltez, DA Nunziato, J Kim, GS Pitt
Nature structural & molecular biology, 2005nature.com
Voltage-gated Ca2+ channel β (Cavβ) subunits have a highly conserved core consisting of
interacting Src homology 3 and guanylate kinase domains, and are postulated to exert their
effects through AID, the major interaction site in the pore-forming α1 subunit. This
stereotypical interaction does not explain how individual Cavβ subunits modulate α1
subunits differentially. Here we show that AID is neither necessary nor sufficient for critical
Cavβ regulatory properties. Complete modulation depends on additional contacts that are …
Abstract
Voltage-gated Ca2+ channel β (Cavβ) subunits have a highly conserved core consisting of interacting Src homology 3 and guanylate kinase domains, and are postulated to exert their effects through AID, the major interaction site in the pore-forming α1 subunit. This stereotypical interaction does not explain how individual Cavβ subunits modulate α1 subunits differentially. Here we show that AID is neither necessary nor sufficient for critical Cavβ regulatory properties. Complete modulation depends on additional contacts that are exclusive of AID and not revealed in recent crystal structures. These data offer a new context for understanding Cavβ modulation, suggesting that the AID interaction orients the Cavβ core so as to permit additional isoform-specific Cavα1-Cavβ interactions that underlie the particular regulation seen with each Cavα1-Cavβ pair, rather than as the main site of regulation.
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