※ PLK family introduction

    PLK (Polo-like kinase) belong to the "Other" group. PLKs are key regulators in cell cycle. Four members have been identified in human genomes which are known as PLK1-4. Sequence analysis show that PLKs are defined by two features: an N-terminal ser/thr protein kinase domain and a C-terminal duplicated polo-box region. Kinase catalytic is highly conserved among all PLKs while the two Polo-box regions are much less conserved which functions as a single unit named "PBD". Human PLK1 is expressed during late G2 and M phases and regulate much of the machineries which are required in mitosis. PLK2 is expressed primarily in early G1 and control the entry into S phase. The expression level of PLK3 is constant durning cell cycle and plays a important role in many stress response pathways. In addition, PLK2 and PLK3 play some similar roles with PLK1 in mitotic functions including Golgi fragmentation and cytokinesis. Like Plk1, Plk4 is essential for cell viability and studies show that PLK4 can also function as tumor suppressor protein (1).

Reference
1. Lowery, D.M., Lim, D. and Yaffe, M.B. (2005) Structure and function of Polo-like kinases. Oncogene, 24, 248-259. PMID: 15640840.

  Reviewed (1)  or Unreviewed (4) 

No.	Status	EKPD ID	Gene ID	Gene Name
1		EKS-POA-00257	ENSPPYG00000001424	PLK3
2		EKS-POA-00255	ENSPPYG00000015057	PLK4
3		EKS-POA-00253	ENSPPYG00000015483	PLK2
4		EKS-POA-00254	ENSPPYG00000007195	PLK1
5		EKS-POA-00256	ENSPPYG00000009323	PLK5