Crosstalk between the chloroplast protein import and SUMO systems revealed through genetic and molecular investigation in Arabidopsis

  1. Samuel Watson
  2. Na Li
  3. Yiting Ye
  4. Feijie Wu
  5. Qihua Ling
  6. R Paul Jarvis  Is a corresponding author
  1. University of Oxford, United Kingdom
  2. Institute of Plant Physiology and Ecology, China
  3. University of Leicester, United Kingdom

Abstract

The chloroplast proteome contains thousands of different proteins that are encoded by the nuclear genome. These proteins are imported into the chloroplast via the action of the TOC translocase and associated downstream systems. Our recent work has revealed that the stability of the TOC complex is dynamically regulated by the ubiquitin-dependent chloroplast-associated protein degradation (CHLORAD) pathway. Here, we demonstrate that the TOC complex is also regulated by the SUMO system. Arabidopsis mutants representing almost the entire SUMO conjugation pathway can partially suppress the phenotype of ppi1, a pale-yellow mutant lacking the Toc33 protein. This suppression is linked to increased abundance of TOC proteins and improvements in chloroplast development. Moreover, data from molecular and biochemical experiments support a model in which the SUMO system directly regulates TOC protein stability. Thus, we have identified a regulatory link between the SUMO system and the chloroplast protein import machinery.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files.

Article and author information

Author details

  1. Samuel Watson

    Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
    Competing interests
    No competing interests declared.
  2. Na Li

    Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
    Competing interests
    No competing interests declared.
  3. Yiting Ye

    Institute of Plant Physiology and Ecology, Shanghai, China
    Competing interests
    No competing interests declared.
  4. Feijie Wu

    University of Leicester, Leicester, United Kingdom
    Competing interests
    No competing interests declared.
  5. Qihua Ling

    Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
    Competing interests
    No competing interests declared.
  6. R Paul Jarvis

    Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
    For correspondence
    paul.jarvis@plants.ox.ac.uk
    Competing interests
    R Paul Jarvis, The application of CHLORAD as a technology for crop improvement is covered by a patent application (no. WO2019/171091 A)..
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2127-5671

Funding

Biotechnology and Biological Sciences Research Council (BB/K018442/1,BB/N006372/1,BB/R016984/1,BB/R009333/1)

  • R Paul Jarvis

Biotechnology and Biological Sciences Research Council (Interdisciplinary Bioscience Doctoral Training Partnership)

  • Samuel Watson

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Heather E McFarlane, University of Toronto, Canada

Publication history

  1. Received: July 11, 2020
  2. Preprint posted: July 22, 2020 (view preprint)
  3. Accepted: September 1, 2021
  4. Accepted Manuscript published: September 2, 2021 (version 1)
  5. Version of Record published: October 7, 2021 (version 2)

Copyright

© 2021, Watson et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Samuel Watson
  2. Na Li
  3. Yiting Ye
  4. Feijie Wu
  5. Qihua Ling
  6. R Paul Jarvis
(2021)
Crosstalk between the chloroplast protein import and SUMO systems revealed through genetic and molecular investigation in Arabidopsis
eLife 10:e60960.
https://doi.org/10.7554/eLife.60960
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