Revisiting the photosystem II repair cycle

The ability of photosystem (PS) II to catalyze the light-driven oxidation of water comes along with its vulnerability to oxidative damage, in particular of the D1 core subunit. Photodamaged PSII undergoes repair in a multi-step process involving (i) reversible phosphorylation of PSII core subunits; (ii) monomerization and lateral migration of the PSII core from grana to stroma thylakoids; (iii) partial disassembly of PSII; (iv) proteolytic degradation of damaged D1; (v) replacement of damaged D1 protein with a new copy; (vi) reassembly of PSII monomers and migration back to grana thylakoids for dimerization and supercomplex assembly. Here we review the current knowledge on the PSII repair cycle.