Caenorhabditis elegans Contains a Third Polo-Like Kinase Gene

Abstract

The Polo family of serine/threonine kinases have been implicated in cell cycle control in a number of diverse organisms. Their localization and biochemical activity suggest that they play an important role in centro-some maturation, G2—to-M phase progression, the promotion of anaphase, and cytokinesis. The Polo family of kinases is distinct from other serine/threonine kinases in that they all contain a polo-box sequence motif in their non-catalytic C-terminal domain. Recently, it was reported that two Polo-related kinases, Plcl and Plc2, are present in C. elegans. Plc2 has diverged from Plcl with poor homology within the polo-box sequence and only had 40% amino acid identity with Plcl. We report here the full-length cDNA sequence of another Polo-related kinase from C. elegans. The predicted protein product has greater than 70% amino acid identity with PLK-1/Plc1, and has a highly conserved polo-box domain.

Key Words:

• Polo-like kinase
• polo-box
• cell cycle
• C. elegans