Options
Characterization of Chloroplast Inner Envelope Membrane Protein,CIA5(Chloroplast-Import-Apparatus)
Date Issued
2004
Date
2004
Author(s)
Teng, Yi-Shan
DOI
zh-TW
Abstract
Abstract
Most chloroplast proteins are encoded by the nucleus, synthesized in the cytosol and imported into chloroplasts. These nucleus-encoded proteins are synthesized as precousors with N-terminal transit peptides, and are transported into chloroplasts by a set of translocon complex located in the chloroplast outer and inner envelope membranes. Translocon components are termed Toc (translocons at the outer envelope membrane of chloroplasts) and Tic (translocons at the inner envelope membrane of chloroplasts) proteins. We have isolated an Arabidopsis mutant, cia5 (chloroplast import apparatus 5), which is defective in chloroplast protein import. CIA5 is predicted to be a membrane premease-like protein, and is extremely conserved in many plant species. Here I show that CIA5 is a chloroplast inner envelope membrane protein containing four transmembrane domains and both its N and C termini face the stroma. I also found that loss of CIA5 resulted in defects in chloroplast protein import, and in reduced amount of inner membrane translocon proteins. Coimmunoprecipiptation studies suggest that CIA5 is a new Tic component.
Most chloroplast proteins are encoded by the nucleus, synthesized in the cytosol and imported into chloroplasts. These nucleus-encoded proteins are synthesized as precousors with N-terminal transit peptides, and are transported into chloroplasts by a set of translocon complex located in the chloroplast outer and inner envelope membranes. Translocon components are termed Toc (translocons at the outer envelope membrane of chloroplasts) and Tic (translocons at the inner envelope membrane of chloroplasts) proteins. We have isolated an Arabidopsis mutant, cia5 (chloroplast import apparatus 5), which is defective in chloroplast protein import. CIA5 is predicted to be a membrane premease-like protein, and is extremely conserved in many plant species. Here I show that CIA5 is a chloroplast inner envelope membrane protein containing four transmembrane domains and both its N and C termini face the stroma. I also found that loss of CIA5 resulted in defects in chloroplast protein import, and in reduced amount of inner membrane translocon proteins. Coimmunoprecipiptation studies suggest that CIA5 is a new Tic component.
Subjects
內膜運輸機組蛋白
葉綠體
chloropolast
CIA5
Type
other
File(s)
No Thumbnail Available
Name
ntu-93-R91226005-1.pdf
Size
23.31 KB
Format
Adobe PDF
Checksum
(MD5):a6819f6283788d17c0289b671e4bff25