Calcium domains around single and clustered IP3 receptors and their modulation by buffers.

ABSTRACT: We study Ca(2+) release through single and clustered IP(3) receptor channels on the ER membrane under presence of buffer proteins. Our computational scheme couples reaction-diffusion equations and a Markovian channel model and allows our investigating the effects of buffer proteins on local calcium concentrations and channel gating. We find transient and stationary elevations of calcium concentrations around active channels and show how they determine release amplitude. Transient calcium domains occur after closing of isolated channels and constitute an important part of the channel's feedback. They cause repeated openings (bursts) and mediate increased release due to Ca(2+) buffering by immobile proteins. Stationary domains occur during prolonged activity of clustered channels, where the

SUBMITTER: Rudiger S 

PROVIDER: S-EPMC2895387 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature