ATP-independent reversal of a membrane protein aggregate by a chloroplast SRP subunit.

ABSTRACT: Membrane proteins impose enormous challenges to cellular protein homeostasis during their post-translational targeting, and they require chaperones to keep them soluble and translocation competent. Here we show that a novel targeting factor in the chloroplast signal recognition particle (cpSRP), cpSRP43, is a highly specific molecular chaperone that efficiently reverses the aggregation of its substrate proteins. In contrast to 'ATPases associated with various cellular activities' (AAA(+)) chaperones, cpSRP43 uses specific binding interactions with its substrate to mediate its 'disaggregase' activity. This disaggregase capability can allow targeting machineries to more effectively capture their protein substrates and emphasizes a close connection between protein folding and trafficking proc

SUBMITTER: Jaru-Ampornpan P 

PROVIDER: S-EPMC2917185 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature