Electrostatic and lipid anchor contributions to the interaction of transducin with membranes: mechanistic implications for activation and translocation.

ABSTRACT: The heterotrimeric G protein transducin is a key component of the vertebrate phototransduction cascade. Transducin is peripherally attached to membranes of the rod outer segment, where it interacts with other proteins at the membrane-cytosol interface. However, upon sustained activation by light, the dissociated G(t)alpha and Gbeta(1)gamma(1) subunits of transducin translocate from the outer segment to other parts of the rod cell. Here we used a computational approach to analyze the interaction strength of transducin and its subunits with acidic lipid bilayers, as well as the range of orientations that they are allowed to occupy on the membrane surface. Our results suggest that the combined constraints of electrostatics and lipid anchors substantially limit the rotational degrees of freedo

SUBMITTER: Kosloff M 

PROVIDER: S-EPMC2576562 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature