Qihua Ling

Control of retrograde signalling by protein import and cytosolic folding stress.

Publisher: Springer Science and Business Media LLC

Date: 06-05-2019

DOI: 10.1038/S41477-019-0415-Y

Abstract: Communication between organelles and the nucleus is essential for fitness and survival. Retrograde signals are cues emitted from the organelles to regulate nuclear gene expression. GENOMES UNCOUPLED1 (GUN1), a protein of unknown function, has emerged as a central integrator, participating in multiple retrograde signalling pathways that collectively regulate the nuclear transcriptome. Here, we show that GUN1 regulates chloroplast protein import through interaction with the import-related chaperone cpHSC70-1. We demonstrated that overaccumulation of unimported precursor proteins (preproteins) in the cytosol causes a GUN phenotype in the wild-type background and enhances the GUN phenotype of the gun1 mutant. Furthermore, we identified the cytosolic HSP90 chaperone complex, induced by overaccumulated preproteins, as a central regulator of photosynthetic gene expression that determines the expression of the GUN phenotype. Taken together, our results suggest a model in which protein import capacity, folding stress and the cytosolic HSP90 complex control retrograde communication.

University Of Leicester

Location: United Kingdom of Great Britain and Northern Ireland

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University Of Oxford

Location: United Kingdom of Great Britain and Northern Ireland

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Institute Of Plant Physiology And Ecology Shanghai Institutes For Biological Sciences

Location: China

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Shanghai Jiao Tong University

Location: China

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CAS Center For Excellence In Molecular Plant Sciences / Institute Of Plant Physiology And Ecology

Location: China

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CAS-JIC Centre Of Excellence For Plant And Microbial Science

Location: China

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