Accessible Requires Authentication Published by De Gruyter October 11, 2012

The gateway to chloroplast: re-defining the function of chloroplast receptor proteins

Wai-Ling Chang, Jürgen Soll and Bettina Bölter
From the journal Biological Chemistry


Chloroplast biogenesis often requires a tight orchestration between gene expression (both plastidial and nuclear) and translocation of ∼3000 nuclear-encoded proteins into the organelle. Protein translocation is achieved via two multimeric import machineries at the outer (TOC) and inner (TIC) envelope of chloroplast, respectively. Three components constitute the core element of the TOC complex: a β-barrel protein translocation channel Toc75 and two receptor constituents, Toc159 and Toc34. A diverse set of distinct TOC complexes have recently been characterized and these diversified TOC complexes have evolved to coordinate the translocation of differentially expressed proteins. This review aims to describe the recent discoveries relating to the typical characteristics of these distinct TOC complexes, particularly the receptor constituents, which are the main contributors for TOC complex diversification.

Corresponding author: Bettina Bölter, Department Biologie I-Botanik, Ludwig-Maximilians-Universität, Großhadernerstrasse 2–4, D-82152 Planegg-Martinsried, Germany; and Munich Center for Integrated Protein Science (CiPSM), Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, D-81377 Munich, Germany

Received: 2012-6-21
Accepted: 2012-8-1
Published Online: 2012-10-11
Published in Print: 2012-11-01

©2012 by Walter de Gruyter Berlin Boston