title: Cytochrome b 6 f function and localization, phosphorylation state of thylakoid membrane proteins and consequences on cyclic electron flow.
abstract: Both the structure and the protein composition of thylakoid membranes have an impact on light harvesting and electron transfer in the photosynthetic chain. Thylakoid membranes form stacks and lamellae where photosystem II and photosystem I localize, respectively. Light-harvesting complexes II can be associated to either PSII or PSI depending on the redox state of the plastoquinone pool, and their distribution is governed by state transitions. Upon state transitions, the thylakoid ultrastructure and lateral distribution of proteins along the membrane are subject to significant rearrangements. In addition, quinone diffusion is limited to membrane microdomains and the cytochrome b 6 f complex localizes either to PSII-containing grana stacks or PSI-containing stroma lamellae. Here, we discuss possible similarities or differences between green algae and C3 plants on the functional consequences of such heterogeneities in the photosynthetic electron transport chain and propose a model in which quinones, accepting electrons either from PSII (linear flow) or NDH/PGR pathways (cyclic flow), represent a crucial control point. Our aim is to give an integrated description of these processes and discuss their potential roles in the balance between linear and cyclic electron flows.
authors.affiliation: Laboratory of Microalgal and Bacterial Bioenergetics and Biotechnology, CEA Cadarache, CNRS, Aix-Marseille Université, UMR7161 BIAM - LB3M, 13108, Saint-Paul-lez-Durance, France.
authors.forename: Louis
authors.initials: L
authors.lastname: Dumas
authors.affiliation: Laboratory of Microalgal and Bacterial Bioenergetics and Biotechnology, CEA Cadarache, CNRS, Aix-Marseille Université, UMR7161 BIAM - LB3M, 13108, Saint-Paul-lez-Durance, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Chazaux
authors.affiliation: Laboratory of Microalgal and Bacterial Bioenergetics and Biotechnology, CEA Cadarache, CNRS, Aix-Marseille Université, UMR7161 BIAM - LB3M, 13108, Saint-Paul-lez-Durance, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Peltier
authors.affiliation: Laboratory of Microalgal and Bacterial Bioenergetics and Biotechnology, CEA Cadarache, CNRS, Aix-Marseille Université, UMR7161 BIAM - LB3M, 13108, Saint-Paul-lez-Durance, France.
authors.forename: Xenie
authors.initials: X
authors.lastname: Johnson
authors.affiliation: Laboratory of Microalgal and Bacterial Bioenergetics and Biotechnology, CEA Cadarache, CNRS, Aix-Marseille Université, UMR7161 BIAM - LB3M, 13108, Saint-Paul-lez-Durance, France. jean.alric@cea.fr.
authors.forename: Jean
authors.initials: J
authors.lastname: Alric
mesh_terms: D000460:Chlorophyta / Q000378:metabolism* / Q000528:radiation effects; D060365:Chloroplast Proteins / Q000378:metabolism / Q000528:radiation effects; D045303:Cytochromes b / Q000378:metabolism* / Q000528:radiation effects; D004579:Electron Transport; D004583:Electrons; D008027:Light; D010084:Oxidation-Reduction; D010766:Phosphorylation; D010788:Photosynthesis / Q000502:physiology; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010971:Plastoquinone / Q000378:metabolism; D020524:Thylakoids / Q000378:metabolism
chemical_list: D060365:Chloroplast Proteins; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D045303:Cytochromes b; D010971:Plastoquinone
keywords: Cyclic electron flow; Cytochrome b 6 f complex; Heterogeneity of thylakoid membranes; Membrane ultrastructure; Quinone microdomains; Redox sensing; State transitions