Alternative splicing of a beta4 subunit proline-rich motif regulates voltage-dependent gating and toxin block of Cav2.1 Ca2+ channels.

ABSTRACT: Ca2+ channel beta subunits modify alpha1 subunit gating properties through direct interactions with intracellular linker domains. In a previous report (Helton and Horne, 2002), we showed that alternative splicing of the beta4 subunit had alpha1 subunit subtype-specific effects on Ca2+ channel activation and fast inactivation. We extend these findings in the present report to include effects on slow inactivation and block by the peptide toxin omega-conotoxin (CTx)-MVIIC. N-terminal deletion and site-directed mutagenesis experiments revealed that the effects of alternative splicing on toxin block and all aspects of gating could be attributed to a proline-rich motif found within N-terminal beta4b amino acids 10-20. Interestingly, this motif is conserved within the third postsynaptic density-9

SUBMITTER: Helton TD 

PROVIDER: S-EPMC6758066 | biostudies-literature | 2002 Nov

REPOSITORIES: biostudies-literature