Involved in defense response to geminivirus infection (By similarity). Phosphorylates RPL10A in vitro. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Inhibited by the viral nuclear shuttle protein (NSP) that binds to the region required for oligomerization. Oligomer. Interacts with geminivirus nuclear shuttle protein (NSP). A number of isoforms are produced. According to EST sequences. Expressed in flowers and roots. Autophosphorylated. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.