title: Photosynthetic complex stoichiometry dynamics in higher plants: biogenesis, function, and turnover of ATP synthase and the cytochrome b6f complex.
abstract: During plant development and in response to fluctuating environmental conditions, large changes in leaf assimilation capacity and in the metabolic consumption of ATP and NADPH produced by the photosynthetic apparatus can occur. To minimize cytotoxic side reactions, such as the production of reactive oxygen species, photosynthetic electron transport needs to be adjusted to the metabolic demand. The cytochrome b6f complex and chloroplast ATP synthase form the predominant sites of photosynthetic flux control. Accordingly, both respond strongly to changing environmental conditions and metabolic states. Usually, their contents are strictly co-regulated. Thereby, the capacity for proton influx into the lumen, which is controlled by electron flux through the cytochrome b6f complex, is balanced with proton efflux through ATP synthase, which drives ATP synthesis. We discuss the environmental, systemic, and metabolic signals triggering the stoichiometry adjustments of ATP synthase and the cytochrome b6f complex. The contribution of transcriptional and post-transcriptional regulation of subunit synthesis, and the importance of auxiliary proteins required for complex assembly in achieving the stoichiometry adjustments is described. Finally, current knowledge on the stability and turnover of both complexes is summarized.
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany Schoettler@mpimp-golm.mpg.de.
authors.forename: Mark Aurel
authors.initials: MA
authors.lastname: Schöttler
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany.
authors.forename: Szilvia Z
authors.initials: SZ
authors.lastname: Tóth
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany.
authors.forename: Alix
authors.initials: A
authors.lastname: Boulouis
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Kahlau
mesh_terms: D000064:Acclimatization; D000255:Adenosine Triphosphate / Q000378:metabolism; D025222:Chloroplast Proton-Translocating ATPases / Q000378:metabolism / Q000502:physiology*; D045346:Cytochrome b6f Complex / Q000378:metabolism / Q000502:physiology*; D004579:Electron Transport; D004777:Environment; D018506:Gene Expression Regulation, Plant; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism
chemical_list: D000255:Adenosine Triphosphate; D045346:Cytochrome b6f Complex; D025222:Chloroplast Proton-Translocating ATPases
keywords: Assembly; assimilation; auxiliary protein; chloroplast ATP synthase; complex turnover; cytochrome b6
  f complex; gene expression; photosynthetic electron transport; translation.