A substrate-independent, 14:3:3 protein-mediated plastid import pathway of NADPH:protochlorophyllide oxidoreductase A.

ABSTRACT: Plastids are semiautonomous organelles that contain only limited coding information in their own DNA. Because most of their genome was transferred to the nucleus after their endosymbiotic origin, plastids must import the major part of their protein constituents from the cytosol. The exact role of cytosolic targeting factors in the regulation of plastid protein import has not been determined. Here, we report that the nucleus-encoded NADPH:protochlorophyllide (Pchlide) oxidoreductase A plastid precursor (pPORA) can use two different plastid import pathways that differ by the requirements for cytosolic 14:3:3 proteins and Hsp70. pPORA synthesized in a wheat germ lysate segregated into different precursor fractions. While import of free pPORA and only Hsp70-complexed pPORA was Pchlide-dependen

SUBMITTER: Schemenewitz A 

PROVIDER: S-EPMC1895985 | biostudies-literature | 2007 May

REPOSITORIES: biostudies-literature