Journal article

Sub-cellular location of FtsH proteases in the cyanobacterium Synechocystis sp PCC 6803 suggests localised PSII repair zones in the thylakoid membranes

Joanna Sacharz, Samantha J Bryan, Jianfeng Yu, Nigel J Burroughs, Edward M Spence, Peter J Nixon, Conrad W Mullineaux



In cyanobacteria and chloroplasts, exposure to HL damages the photosynthetic apparatus, especially the D1 subunit of Photosystem II. To avoid chronic photoinhibition, a PSII repair cycle operates to replace damaged PSII subunits with newly synthesised versions. To determine the sub-cellular location of this process, we examined the localisation of FtsH metalloproteases, some of which are directly involved in degrading damaged D1. We generated transformants of the cyanobacterium Synechocystis sp. PCC6803 expressing GFP-tagged versions of its four FtsH proteases. The ftsH2-gfp strain was functional for PSII repair under our conditions. Confocal microscopy shows that FtsH1 is mainly in the cyto..

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Awarded by Biotechnology and Biological Sciences Research Council

Awarded by BBSRC

Funding Acknowledgements

JS was supported by Marie Curie Initial Training Networks (HARVEST), Framework Programme of the European Union (FP7-PEOPLE-ITN-2008). SJB was supported by Biotechnology and Biological Sciences Research Council grant (BB/G021856) and JY by grant (BB/F020554/1). Thanks to T. Ogura for providing antibodies to E. coli FtsH, T. Ogawa for antibodies to Synechocystis SbtA and Dr Paul Hitchin (CISBIO mass spectrometry facility, Imperial College) for mass spectrometry analysis.