Separate elements within a single IQ-like motif in adenylyl cyclase type 8 impart ca2+/calmodulin binding and autoinhibition.

ABSTRACT: The ubiquitous Ca(2+)-sensing protein calmodulin (CaM) fulfills its numerous signaling functions through a wide range of modular binding and activation mechanisms. By activating adenylyl cyclases (ACs) 1 and 8, Ca(2+) acting via calmodulin impacts on the signaling of the other major cellular second messenger cAMP. In possessing two CaM-binding domains, a 1-5-8-14 motif at the N terminus and an IQ-like motif (IQlm) at the C terminus, AC8 offers particularly sophisticated regulatory possibilities. The IQlm has remained unexplored beyond the suggestion that it bound CaM, and the larger C2b region of which it is part was involved in the relief of autoinhibition of AC8. Here we attempt to distinguish the function of individual residues of the IQlm. From a complementary approach of in vitro and

SUBMITTER: Macdougall DA 

PROVIDER: S-EPMC2708854 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature