Enables cyclin-dependent protein serine/threonine kinase activity and protein kinase binding activity. Involved in several processes, including positive regulation of meiotic nuclear division; positive regulation of proteasomal ubiquitin-dependent protein catabolic process; and sexual reproduction. Acts upstream of or within nematode male tail tip morphogenesis. Located in cytoplasm and nucleus. Expressed in embryonic cell and germ cell. Human ortholog(s) of this gene implicated in several diseases, including cervical cancer; hepatobiliary system cancer (multiple); and transitional cell carcinoma. Is an ortholog of human CDK1 (cyclin dependent kinase 1).