Casein kinase I-like protein linked to lipase in plant.

Casein kinase I (CKI) is a Ser/Thr kinase protein that is highly conserved from plants to animals. This enzyme is involved in various cellular functions, such as DNA repair, cell cycle, cytokinesis, vesicular trafficking, morphogenesis and circadian rhythm. The CKI family contains a highly conserved kinase domain at the N-terminus and a highly diverse regulatory domain at the C-terminus. The CKI-like protein has been indentified in rice and the 2.0 Å crystal structure of the kinase domain of the CKI-like protein from rice (riceCKI) was reported by our group recently. We also identified a lipase that was a substrate of riceCKI and showed that the activity of the lipase is controlled by the activity of riceCKI. Here, we identified potential phosphorylation sites on the lipase by molecular modeling and ser/thr mapping. Moreover, we showed that the activity of the lipase was decreased by CKI in a time-dependent manner.