The Ca(V) 1.2 Ca(2+) channel is expressed in sarcolemma of type I and IIa myofibers of adult skeletal muscle

Muscle Nerve. 2007 Oct;36(4):482-90. doi: 10.1002/mus.20842.

Abstract

Although Ca(2+)-dependent signaling pathways are important for skeletal muscle plasticity, the sources of Ca(2+) that activate these signaling pathways are not completely understood. Influx of Ca(2+) through surface membrane Ca(2+) channels may activate these pathways. We examined expression of two L-type Ca(2+) channels in adult skeletal muscle, the Ca(V) 1.1 and Ca(V) 1.2, with isoform-specific antibodies in Western blots and immunocytochemistry assays. Consistent with a large body of work, expression of the Ca(V) 1.1 was restricted to skeletal muscle where it was expressed in T-tubules. Ca(V) 1.2 was also expressed in skeletal muscle, in the sarcolemma of type I and IIa myofibers. Exercise-induced alterations in muscle fiber types cause a concomitant increase in the number of both Ca(V) 1.2 and type IIa-positive fibers. Taken together, these data suggest that the Ca(V) 1.2 Ca(2+) channel is expressed in adult skeletal muscle in a fiber type-specific manner, which may help to maintain oxidative muscle phenotype.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Calcium Channels, L-Type / metabolism*
  • Caveolin 3 / metabolism
  • Dystrophin / metabolism
  • Muscle Fibers, Fast-Twitch / metabolism
  • Muscle Fibers, Fast-Twitch / ultrastructure*
  • Muscle Fibers, Slow-Twitch / metabolism
  • Muscle Fibers, Slow-Twitch / ultrastructure*
  • Muscle, Skeletal / cytology*
  • Protein Isoforms / metabolism
  • Rats
  • Sarcolemma / metabolism*

Substances

  • Calcium Channels, L-Type
  • Caveolin 3
  • Dystrophin
  • L-type calcium channel alpha(1C)
  • Protein Isoforms