Abstract
Cyclobutane pyrimidine dimer (CPD) photolyase is a crucial factor for determining UVB sensitivity in plants. We previously found that native rice CPD photolyase have two protein of about 54 kDa and 56 kDa. Treatment with protein phosphatase revealed that the 56-kDa native rice CPD photolyase was phosphorylated. Our finding is the first demonstration that the CPD photolyase is phosphorylated. In this study, we investigated the effect of phosphorylation on CPD photolyase activity. First, the purified native rice CPD photolyase was treated with protein phosphatase, and then the activity of dephosphorylated CPD photolyase was compared with the purified native rice CPD photolyase, including phosphorylated CPD photolyase. Next, the phosphorylated CPD photolyase was isolated by phosphate metal affinity chromatography, and then the activity of the phosphorylated CPD photolyase was measured. We discuss the effect of phosphorylation on the CPD photolyase activity.
