title: Core protein phosphorylation facilitates the repair of photodamaged photosystem II at high light.
abstract: Phosphorylation of photosystem II (PSII) reaction center protein D1 has been hypothesised to function as a signal for the migration of photodamaged PSII core complex from grana membranes to stroma lamellae for concerted degradation and replacement of the photodamaged D1 protein. Here, by using the mutants with impaired capacity (stn8) or complete lack (stn7 stn8) in phosphorylation of PSII core proteins, the role of phosphorylation in PSII photodamage and repair was investigated. We show that the lack of PSII core protein phosphorylation disturbs the disassembly of PSII supercomplexes at high light, which is a prerequisite for efficient migration of damaged PSII complexes from grana to stroma lamellae for repair. This results in accumulation of photodamaged PSII complexes, which in turn results, upon prolonged exposure to high light (HL), in general oxidative damage of photosynthetic proteins in the thylakoid membrane.
authors.affiliation: Plant Physiology and Molecular Biology, Department of Biology, University of Turku, FIN-20014 Turku, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Tikkanen
authors.forename: Markus
authors.initials: M
authors.lastname: Nurmi
authors.forename: Saijaliisa
authors.initials: S
authors.lastname: Kangasjärvi
authors.forename: Eva-Mari
authors.initials: EM
authors.lastname: Aro
mesh_terms: D029681:Arabidopsis Proteins / Q000378:metabolism*; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D008027:Light; D010766:Phosphorylation; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D029681:Arabidopsis Proteins; D045332:Photosystem II Protein Complex