Leicester Research Archive

Leicester Research Archive >
College of Medicine, Biological Sciences and Psychology >
Biology, Department of >
Published Articles, Dept. of Biology >

Please use this identifier to cite or link to this item: http://hdl.handle.net/2381/10864

Title: Molecular chaperone involvement in chloroplast protein import
Authors: Flores-Pérez, Úrsula
Jarvis, Paul
Issue Date: 12-Apr-2012
Publisher: Elsevier
Citation: Biochimica et Biophysica Acta - Molecular Cell Research, 2012, available online in advance of print
Abstract: Chloroplasts are organelles of endosymbiotic origin that perform essential functions in plants. They contain about 3000 different proteins, the vast majority of which are nucleus-encoded, synthesized in precursor form in the cytosol, and transported into the chloroplasts post-translationally. These preproteins are generally imported via envelope complexes termed TOC and TIC (Translocon at the Outer/Inner envelope membrane of Chloroplasts). They must navigate different cellular and organellar compartments (e.g., the cytosol, the outer and inner envelope membranes, the intermembrane space, and the stroma) before arriving at their final destination. It is generally considered that preproteins are imported in a largely unfolded state, and the whole process is energy-dependent. Several chaperones and cochaperones have been found to mediate different stages of chloroplast import, in similar fashion to chaperone involvement in mitochondrial import. Cytosolic factors such as Hsp90, Hsp70 and 14-3-3 may assist preproteins to reach the TOC complex at the chloroplast surface, preventing their aggregation or degradation. Chaperone involvement in the intermembrane space has also been proposed, but remains uncertain. Preprotein translocation is completed at the trans side of the inner membrane by ATP-driven motor complexes. A stromal Hsp100-type chaperone, Hsp93, cooperates with Tic110 and Tic40 in one such motor complex, while stromal Hsp70 is proposed to act in a second, parallel complex. Upon arrival in the stroma, chaperones (e.g., Hsp70, Cpn60, cpSRP43) also contribute to the folding, assembly or onward intraorganellar guidance of the proteins. In this review, we focus on chaperone involvement during preprotein translocation at the chloroplast envelope. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
DOI Link: 10.1016/j.bbamcr.2012.03.019
ISSN: 0167-4889
eISSN: 1879-2596
Links: http://www.sciencedirect.com/science/article&(...)
http://hdl.handle.net/2381/10864
Version: Post-print
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © 2012 Published by Elsevier B.V. Deposited with reference to the publisher's archiving policy available on the SHERPA/RoMEO website. NOTICE: this is the author’s version of a work that was accepted for publication in Biochimica et Biophysica Acta - Molecular Cell Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochimica et Biophysica Acta - Molecular Cell Research, 2012, available online in advance of print on 12 April 2012.
Appears in Collections:Published Articles, Dept. of Biology

Files in This Item:

File Description SizeFormat
BBAMCR-12-21R1 for LRA.pdfPost-review (final submitted)273.07 kBAdobe PDFView/Open
View Statistics

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.

 

MAINTAINER