Protein import across chloroplast envelopes

摘要

The vast majority of chloroplast proteins is nuclear encoded and cytoplasmically expressed as precursor proteins. As a consequence preproteins destined for the organelle interior need to be posttranslationally imported into the chloroplast across both envelope membranes. The translocation involves two distinct import complexes at the outer and inner envelope membrane in cooperation with soluble factors in the cytosol and the stroma. Within the last years several proteins have been identified as members of the chloroplast import machinery, and understanding of the import process is rising.