May be involved in plant development processes (Probable). May function downstream of DCW11 in retrograde signaling from the mitochondria to the nucleus. Seems to be involved in the mechanism of cytoplasmic male sterility (CMS) occurrence (PubMed:19224952). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts with PLIM2B. Expressed in pollen grains. Expressed in anthers from the bi-cellular to the tri-cellular pollen stage. Expression in anthers at the tri-cellular pollen stage is down-regulated in cytoplasmic male sterility (CMS) rice lines. Belongs to the protein kinase superfamily. NEK Ser/Thr protein kinase family. NIMA subfamily.