Abstract
PsbP, an extrinsic subunit of photosystem II (PSII), is a nuclear-encoded protein that optimizes the water-splitting reaction. In addition to PsbP, higher plants have a number of PsbP paralogs that include the PsbP-like 1 (PPL1) protein, a putative ortholog of cyanobacterial PsbP homolog (cyanoP). In our previous study, we characterized an Arabidopsis mutant lacking PPL1 and demonstrated that PSII activity was sensitive to high-intensity light and the recovery of photoinhibited PSII activity was delayed in ppl1 mutant plants (Ishihara et al., Plant Physiology 2007). In order to elucidate how PPL1 is involved in the PSII repair cycle, molecular behaviors of PPL1 were further analyzed using Arabidopsis wild-type (Col-0) and various mutants that have a defect to maintain the normal PSII activities. Localization of PPL1 in the thylakoid membranes was also analyzed.
