Polo-like kinase

Polo-like kinases (PLKs) are a family of serine/threonine-protein kinases that play critical roles in the regulation of the cell cycle, particularly during mitosis. They are named after the Drosophila gene polo, which is essential for mitotic spindle formation.

Function

Polo-like kinases are involved in various stages of cell division, including the activation of cyclin-dependent kinase 1 (CDK1), the maturation of the centrosome, the formation of the mitotic spindle, and the regulation of cytokinesis. PLKs are also implicated in the DNA damage response and the maintenance of genomic stability.

Isoforms

There are five known isoforms of polo-like kinases in humans:

• PLK1: The most studied member, PLK1 is crucial for the progression of mitosis and is often overexpressed in cancer cells.
• PLK2: Also known as serum-inducible kinase, PLK2 is involved in synaptic plasticity and neuronal development.
• PLK3: Plays a role in the response to DNA damage and oxidative stress.
• PLK4: Essential for centriole duplication and is a key regulator of cell cycle progression.
• PLK5: A less characterized member, PLK5 is thought to have a role in neuronal differentiation.

Clinical Significance

Due to their pivotal role in cell division, polo-like kinases are considered potential targets for cancer therapy. Inhibitors of PLK1, such as volasertib, are being investigated in clinical trials for their efficacy in treating various types of cancer.

See Also

• Cell cycle
• Mitosis
• Protein kinase
• Cancer therapy

External Links

• PLK1 Gene - NCBI
• PLK1 - UniProt