?
 
Catalytic domain of the Serine/Threonine Kinase, Polo-like kinase 1 STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. PLKs play important roles in cell cycle progression and in DNA damage responses. They regulate mitotic entry, mitotic exit, and cytokinesis. In general PLKs contain an N-terminal catalytic kinase domain and a C-terminal regulatory polo box domain (PBD), which is comprised by two bipartite polo-box motifs (or polo boxes) and is involved in protein interactions. There are five mammalian PLKs (PLK1-5) from distinct genes. PLK1 functions as a positive regulator of mitosis, meiosis, and cytokinesis. Its localization changes during mitotic progression; associating first with centrosomes in prophase, with kinetochores in prometaphase and metaphase, at the central spindle in anaphase, and in the midbody during telophase. It carries multiple functions throughout the cell cycle through interactions with differrent substrates at these specific subcellular locations. PLK1 is overexpressed in many human cancers and is associated with poor prognosis. The PLK1 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",