Association of Psb28 and Psb27 Proteins with PSII-PSI Supercomplexes upon Exposure of Synechocystis sp PCC 6803 to High Light

0476121 - MBÚ 2018 RIV GB eng J - Journal Article
Bečková, Martina - Gardian, Zdenko - Yu, J.F. - Koník, Peter - Nixon, P. J. - Komenda, Josef
Association of Psb28 and Psb27 Proteins with PSII-PSI Supercomplexes upon Exposure of Synechocystis sp PCC 6803 to High Light.
Molecular Plant. Roč. 10, č. 1 (2017), s. 62-72. ISSN 1674-2052. E-ISSN 1752-9867
R&D Projects: GA ČR GBP501/12/G055; GA MŠMT(CZ) LO1416; GA MŠMT(CZ) ED2.1.00/19.0392
Institutional support: RVO:61388971 ; RVO:60077344
Keywords : Psb28 proteins * photosystem I and II * Synechocystis
OECD category: Microbiology; Biochemistry and molecular biology (BC-A)
Impact factor: 9.326, year: 2017

Formation of the multi-subunit oxygen-evolving photosystem II (PSII) complex involves a number of auxiliary protein factors. In this study we compared the localization and possible function of two homologous PSII assembly factors, Psb28-1 and Psb28-2, from the cyanobacterium Synechocystis sp. PCC 6803. We demonstrate that FLAG-tagged Psb28-2 is present in both the monomeric PSII core complex and a PSII core complex lacking the inner antenna CP43 (RC47), whereas Psb28-1 preferentially binds to RC47. When cells are exposed to increased irradiance, both tagged Psb28 proteins additionally associate with oligomeric forms of PSII and with PSII-PSI supercomplexes composed of trimeric photosystem I (PSI) and two PSII monomers as deduced from electron microscopy. The presence of the Psb27 accessory protein in these complexes suggests the involvement of PSI in PSII biogenesis, possibly by photoprotecting PSII through energy spillover. Under standard culture conditions, the distribution of PSII complexes is similar in the wild type and in each of the single psb28 null mutants except for loss of RC47 in the absence of Psb28-1. In comparison with the wild type, growth of mutants lacking Psb28-1 and Psb27, but not Psb28-2, was retarded under high-light conditions and, especially, intermittent high-light/dark conditions, emphasizing the physiological importance of PSII assembly factors for light acclimation.
Permanent Link: http://hdl.handle.net/11104/0272656