Transmembrane topogenesis of a tail-anchored protein is modulated by membrane lipid composition.

ABSTRACT: A large class of proteins with cytosolic functional domains is anchored to selected intracellular membranes by a single hydrophobic segment close to the C-terminus. Although such tail-anchored (TA) proteins are numerous, diverse, and functionally important, the mechanism of their transmembrane insertion and the basis of their membrane selectivity remain unclear. To address this problem, we have developed a highly specific, sensitive, and quantitative in vitro assay for the proper membrane-spanning topology of a model TA protein, cytochrome b5 (b5). Selective depletion from membranes of components involved in cotranslational protein translocation had no effect on either the efficiency or topology of b5 insertion. Indeed, the kinetics of transmembrane insertion into protein-free phospholipid

SUBMITTER: Brambillasca S 

PROVIDER: S-EPMC1176458 | biostudies-literature | 2005 Jul

REPOSITORIES: biostudies-literature