title: Slr0151 in Synechocystis sp. PCC 6803 is required for efficient repair of photosystem II under high-light condition.
abstract: Cyanobacteria are ancient photosynthetic prokaryotes that have adapted successfully to adverse environments including high-light irradiation. Although it is known that the repair of photodamaged photosystem II (PSII) in the organisms is a highly regulated process, our knowledge of the molecular components that regulate each step of the process is limited. We have previously identified a hypothetical protein Slr0151 in the membrane fractions of cyanobacterium Synechocystis sp. PCC 6803. Here, we report that Slr0151 is involved in PSII repair of the organism. We generated a mutant strain (Δslr0151) lacking the protein Slr0151 and analyzed its characteristics under normal and high-light conditions. Targeted deletion of slr0151 resulted in decreased PSII activity in Synechocystis. Moreover, the mutant exhibited increased photoinhibition due to impairment of PSII repair under high-light condition. Further analysis using in vivo radioactive labeling and 2-D blue native/sodium dodecylsulfate polyacrylamide gel electrophoresis indicated that the PSII repair cycle was hindered at the levels of D1 synthesis and disassembly and/or assembly of PSII in the mutant. Protein interaction assays demonstrated that Slr0151 interacts with D1 and CP43 proteins. Taken together, these results indicate that Slr0151 plays an important role in regulating PSII repair in the organism under high-light stress condition.
authors.affiliation: Key Laboratory of Photobiology, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Haomeng
authors.initials: H
authors.lastname: Yang
authors.forename: Libing
authors.initials: L
authors.lastname: Liao
authors.forename: Tingting
authors.initials: T
authors.lastname: Bo
authors.forename: Lei
authors.initials: L
authors.lastname: Zhao
authors.forename: Xuwu
authors.initials: X
authors.lastname: Sun
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Lu
authors.forename: Birgitta
authors.initials: B
authors.lastname: Norling
authors.forename: Fang
authors.initials: F
authors.lastname: Huang
mesh_terms: D017353:Gene Deletion; D008027:Light; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D045332:Photosystem II Protein Complex / Q000235:genetics*; D046939:Synechocystis / Q000235:genetics* / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D008565:Membrane Proteins; D045332:Photosystem II Protein Complex
keywords: Cyanobacteria; Slr0151; Synechocystis; membrane protein; photosystem II repair