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

作者:Jaru Am****pan Peera; Shen Kuang; Lam Vinh Q; Ali Mona; Doniach Sebastian; Jia Tony Z; Shan Shu ou*
来源:Nature Structural & Molecular Biology, 2010, 17(6): 696-U64.
DOI:10.1038/nsmb.1836

摘要

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 processes. Moreover, cpSRP43 provides the first example to our knowledge of an ATP-independent disaggregase and shows that efficient reversal of protein aggregation can be attained by specific binding interactions between a chaperone and its substrate.

  • 出版日期2010-6