Stimulation of mammalian G-protein-responsive adenylyl cyclases by carbon dioxide.

ABSTRACT: Carbon dioxide is fundamental to the physiology of all organisms. There is considerable interest in the precise molecular mechanisms that organisms use to directly sense CO(2). Here we demonstrate that a mammalian recombinant G-protein-activated adenylyl cyclase and the related Rv1625c adenylyl cyclase of Mycobacterium tuberculosis are specifically stimulated by CO(2). Stimulation occurred at physiological concentrations of CO(2) through increased k(cat). CO(2) increased the affinity of enzyme for metal co-factor, but contact with metal was not necessary as CO(2) interacted directly with apoenzyme. CO(2) stimulated the activity of both G-protein-regulated adenylyl cyclases and Rv1625c in vivo. Activation of G-protein regulated adenylyl cyclases by CO(2) gave a corresponding increase in cAM

SUBMITTER: Townsend PD 

PROVIDER: S-EPMC2613629 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature