Thioredoxin targets of the plant chloroplast lumen and their implications for plastid function

Research output: Contribution to journalArticle

Abstract

The light-dependent regulation of stromal enzymes by thioredoxin (Trx)-catalysed disulphide/dithiol exchange is known as a classical mechanism for control of chloroplast metabolism. Recent proteome studies show that Trx targets are present not only in the stroma but in all chloroplast compartments, from the envelope to the thylakoid lumen. Trx-mediated redox control appears to be a common feature of important pathways, such as the Calvin cycle, starch synthesis and tetrapyrrole biosynthesis. However, the extent of thiol-dependent redox regulation in the thylakoid lumen has not been previously systematically explored. In this study, we addressed Trx-linked redox control in the chloroplast lumen of Arabidopsis thaliana. Using complementary proteomics approaches, we identified 19 Trx target proteins, thus covering more than 40% of the currently known lumenal chloroplast proteome. We show that the redox state of thiols is decisive for degradation of the extrinsic PsbO1 and PsbO2 subunits of photosystem II. Moreover, disulphide reduction inhibits activity of the xanthophyll cycle enzyme violaxanthin deepoxidase, which participates in thermal dissipation of excess absorbed light. Our results indicate that redox-controlled reactions in the chloroplast lumen play essential roles in the function of photosystem II and the regulation of adaptation to light intensity.

Details

Authors
  • Michael Hall
  • Alejandro Mata-Cabana
  • Hans-Erik Åkerlund
  • Francisco J. Florencio
  • Wolfgang P. Schroder
  • Marika Lindahl
  • Thomas Kieselbach
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biological Sciences

Keywords

  • proteomics, Violaxanthin de-epoxidase, Disulphide, D1-processing, Immunophilin, Plant, Pentapeptide protein
Original languageEnglish
Pages (from-to)987-1001
JournalProteomics
Volume10
Issue number5
Publication statusPublished - 2010
Publication categoryResearch
Peer-reviewedYes