1. Regulation of Light Harvesting in Chlamydomonas reinhardtii Two Protein Phosphatases Are Involved in State Transitions
- Author
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Paolo Longoni, Linnka Lefebvre-Legendre, Michel Goldschmidt-Clermont, Marie Chazaux, Bart Ghysels, Federica Cariti, Xenie Johnson, University of Geneva [Switzerland], Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Université de Neuchâtel (UNINE), Université de Liège, ANR-14CE05-0041-01, European Commission's Marie Curie Initial Training Network project (AccliPhot grant) PITNGA-2012-316427, European Project: 516510 ,SOLAR-H, Université de Genève = University of Geneva (UNIGE), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Photosynthèse & Environnement (P&E), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA))
- Subjects
0106 biological sciences ,Physiology ,[SDV]Life Sciences [q-bio] ,Phosphatase ,Arabidopsis ,Light-Harvesting Protein Complexes ,Chlamydomonas reinhardtii ,Context (language use) ,Plant Science ,macromolecular substances ,Protein Serine-Threonine Kinases ,Thylakoids ,01 natural sciences ,Electron Transport ,Phosphoprotein Phosphatases ,Genetics ,Protein phosphorylation ,News and Views ,Research Articles ,Photosystem I Protein Complex ,biology ,Arabidopsis Proteins ,Chemistry ,Kinase ,Photosystem II Protein Complex ,biology.organism_classification ,Thylakoid ,Biophysics ,Phosphorylation ,Protein Kinases ,010606 plant biology & botany - Abstract
International audience; Protein phosphorylation plays important roles in short-term regulation of photosynthetic electron transfer, and during state transitions, the kinase STATE TRANSITION7 (STT7) ofChlamydomonas reinhardtiiphosphorylates components of light-harvesting antenna complex II (LHCII). This reversible phosphorylation governs the dynamic allocation of a part of LHCII to PSI or PSII, depending on light conditions and metabolic demands, but counteracting phosphatase(s) remain unknown inC. reinhardtii. Here we analyzed state transitions inC. reinhardtiimutants of two phosphatases, PROTEIN PHOSPHATASE1 and PHOTOSYSTEM II PHOSPHATASE, which are homologous to proteins that antagonize the state transition kinases (STN7 and STN8) in Arabidopsis (Arabidopsis thaliana). The transition from state 2 to state 1 was retarded inpph1, and surprisingly also inpbcp. However, both mutants eventually returned to state 1. In contrast, the double mutantpph1;pbcpappeared strongly locked in state 2. The complex phosphorylation patterns of the LHCII trimers and of the monomeric subunits were affected in the phosphatase mutants. Their analysis indicated that the two phosphatases have different yet overlapping sets of protein targets. The dual control of thylakoid protein dephosphorylation and the more complex antenna phosphorylation patterns inC. reinhardtiicompared to Arabidopsis are discussed in the context of the stronger amplitude of state transitions and the more diverse LHCII isoforms in the alga.
- Published
- 2020