Correcting the R165K substitution in the first voltage-sensor of Ca_V1.1 right-shifts the voltage-dependence of skeletal muscle calcium channel activation.

ABSTRACT: The voltage-gated calcium channel Ca_V1.1a primarily functions as voltage-sensor in skeletal muscle excitation-contraction (EC) coupling. In embryonic muscle the splice variant Ca_V1.1e, which lacks exon 29, additionally function as a genuine L-type calcium channel. Because previous work in most laboratories used a Ca_V1.1 expression plasmid containing a single amino acid substitution (R165K) of a critical gating charge in the first voltage-sensing domain (VSD), we corrected this substitution and analyzed its effects on the gating properties of the L-type calcium currents in dysgenic myotubes. Reverting K165 to R right-shifted the voltage-dependence of activation by ~12 mV in both Ca_V1.1 splice variants without changing their current amplitudes or k

SUBMITTER: El Ghaleb Y 

PROVIDER: S-EPMC6380215 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature