Molecular determinants of Gem protein inhibition of P/Q-type Ca2+ channels.

ABSTRACT: The RGK family of monomeric GTP-binding proteins potently inhibits high voltage-activated Ca(2+) channels. The molecular mechanisms of this inhibition are largely unclear. In Xenopus oocytes, Gem suppresses the activity of P/Q-type Ca(2+) channels on the plasma membrane. This is presumed to occur through direct interactions of one or more Gem inhibitory sites and the pore-forming Ca(v)2.1 subunit in a manner dependent on the Ca(2+) channel subunit β (Ca(v)β). In this study we investigated the molecular determinants in Gem that are critical for this inhibition. Like other RGK proteins, Gem contains a conserved Ras-like core and extended N and C termini. A 12-amino acid fragment in the C terminus was found to be crucial for and sufficient to produce Ca(v)β-dependent inhibition, suggesting th

SUBMITTER: Fan M 

PROVIDER: S-EPMC3391154 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature