Description
The polo-like kinases (Plks) are a family of conserved serine/threonine kinases that play a critical role in the normal progression of cells through mitosis. The Plk3 serine/threonine kinase is a mammalian member of this family. In contract to Plk1, overexpression of Plk3 in mammalian cells suppresses proliferation and inhibits colony formation. Subsequent analysis demonstrated that overexpression of Plk3 induces chromatin condensation and apoptosis. One difference between Plk1 and the other two Plks is that both Plk2 and Plk3 were originally identified as immediate-early genes, whereas Plk1 does not share this characteristic. The Plks have been implicated in the genesis or progression of tumors. Plk3 has been suggested as a candidate tumor suppressor, and its expression is down-regulated or absent in lung carcinomas and squamous cell carcinomas of the head and neck