Multiple Ca(2+)-binding sites in the extracellular domain of the Ca(2+)-sensing receptor corresponding to cooperative Ca(2+) response.

ABSTRACT: A small change in the extracellular Ca(2+) concentration ([Ca(2+)](o)) integrates cell signaling responses in multiple cellular and tissue networks and functions via activation of Ca(2+)-sensing receptors (CaSR). Mainly through binding of Ca(2+) to the large extracellular domain (ECD) of the dimeric CaSR, intracellular Ca(2+) responses are highly cooperative with an apparent Hill coefficient ranging from 2 to 4. We have previously reported the identification of two continuous putative Ca(2+)-binding sites by grafting CaSR-derived, Ca(2+)-binding peptides to a scaffold protein, CD2, that does not bind Ca(2+). In this paper, we predict more potential noncontinuous Ca(2+)-binding sites in the ECD. We dissect the intact CaSR into three globular subdomains, each of which contains two to three p

SUBMITTER: Huang Y 

PROVIDER: S-EPMC2627791 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature