JCB logo
Accuri Cytometers
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
Published 7 November 2005. doi:10.1083/jcb.200506171
The Rockefeller University Press, 0021-9525 $8.00
JCB, Volume 171, Number 3, 425-430
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 1793K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Inoue, K.
Right arrow Articles by Ohme-Takagi, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Inoue, K.
Right arrow Articles by Ohme-Takagi, M.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Report

 Complete maturation of the plastid protein translocation channel requires a type I signal peptidase

Kentaro Inoue1, Amy J. Baldwin1, Rebecca L. Shipman1, Kyoko Matsui3, Steven M. Theg2, and Masaru Ohme-Takagi3

1 Department of Plant Sciences, College of Agricultural and Environmental Sciences
2 Section of Plant Biology, College of Biological Sciences, University of California, Davis, Davis, CA 95616
3 Gene Function Research Laboratory, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan

Correspondence to Kentaro Inoue: kinoue{at}ucdavis.edu


Abstract
The protein translocation channel at the plastid outer envelope membrane, Toc75, is essential for the viability of plants from the embryonic stage. It is encoded in the nucleus and is synthesized with a bipartite transit peptide that is cleaved during maturation. Despite its important function, the molecular mechanism and the biological significance of the full maturation of Toc75 remain unclear. In this study, we show that a type I signal peptidase (SPase I) is responsible for this process. First, we demonstrate that a bacterial SPase I converted Toc75 precursor to its mature form in vitro. Next, we show that disruption of a gene encoding plastidic SPase I (Plsp1) resulted in the accumulation of immature forms of Toc75, severe reduction of plastid internal membrane development, and a seedling lethal phenotype. These phenotypes were rescued by the overexpression of Plsp1 complementary DNA. Plsp1 appeared to be targeted both to the envelope and to the thylakoidal membranes; thus, it may have multiple functions.

A.J. Baldwin and R.L. Shipman contributed equally to this paper.

Abbreviations used in this paper: Lep, leader peptidase; OE33, 33-kD component of the oxygen-evolving complex; PLB, prolamellar body; Plsp1, plastidic SPase I; POR, protochlorophyllide oxidoreductase; SPase I, type I signal peptidase; Toc, translocon at the outer envelope membrane of chloroplasts.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents