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Updated: Jul 4, 2026

Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays
Published on: September 28, 2018
Protein disulfide isomerase as a regulator of chloroplast translational activation
1Department of Cell Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Abstract:
Light-regulated translation of chloroplast messenger RNAs (mRNAs) requires trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. Chloroplast polyadenylate-binding protein (cPABP) specifically binds to the 5'-UTR of the psbA mRNA and is essential for translation of this mRNA. A protein disulfide isomerase that is localized to the chloroplast and copurifies with cPABP was shown to modulate the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP through redox potential or adenosine 5'-diphosphate-dependent phosphorylation. This mechanism allows for a simple reversible switch regulating gene expression in the chloroplast.
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