Enables protein serine/threonine kinase activity. Involved in organelle organization; positive regulation of nematode male tail tip morphogenesis; and regulation of cell cycle. Located in several cellular components, including condensed chromosome; microtubule cytoskeleton; and nucleus. Expressed in AB and embryonic cell. Human ortholog(s) of this gene implicated in several diseases, including breast carcinoma; reproductive organ cancer (multiple); and urinary bladder cancer. Is an ortholog of human PLK1 (polo like kinase 1).