Characterization of the gating brake in the I-II loop of CaV3 T-type calcium channels.

ABSTRACT: Our interest was drawn to the I-II loop of Cav3 channels for two reasons:  one, transfer of the I-II loop from a high voltage-activated channel (Cav2.2) to a low voltage-activated channel (Cav3.1) unexpectedly produced an ultra-low voltage activated channel; and two, sequence variants of the I-II loop found in childhood absence epilepsy patients altered channel gating and increased surface expression of Cav3.2 channels. To determine the roles of this loop we have studied the structure of the loop and the biophysical consequences of altering its structure.  Deletions localized the gating brake to the first 62 amino acids after IS6 in all three Cav3 channels, establishing the evolutionary conservation of this region and its function.  Circular dichroism was performed on a purified fragment o

SUBMITTER: Perez-Reyes E 

PROVIDER: S-EPMC3052245 | biostudies-literature | 2010 Nov-Dec

REPOSITORIES: biostudies-literature