Polo-Like Kinase-1 (PLK1, also known as Serine/Threonine Protein Kinase 13) is a 66 kDa kinase. The activity of PLK-1 is crucial for mitosis & maintenance of genome stability. PLK-1 localizes to centrosomes & kinetochores where it plays a key role in late prophase & prometaphase. PLK-1 is overexpressed in many types of cancers and mediates estrogen receptor-mediated gene transcription in breast cancer cells.
Overexpression of PLK-1 is associated with tumour development, with elevated levels of expression reported in non-small cell lung cancers, head & neck, gastric, breast, ovarian, colon and several other cancer types.