CDK Signaling Pathway
The transition between different states of the eukaryotic cell cycle is mainly
controlled by checkpoints, which consist of two protein families: cyclin-dependent
protein kinase (CDK) and cycling. The former monomer has no enzymatic activity and
can only be activated when it forms a CDK-cyclin complex with the latter. A series of
events associated with cell state transitions in the cell cycle are then initiated by
specifically phosphorylating specific serine and threonine residues on the target
protein. The latter is a class of proteins that aggregate and degrade in the cell cycle
as cells change, and they regulate their activity by forming complexes with CDK,
which are essential for CDK expression activity. The aggregation, activation, and
depolymerization of the periodic CDK-cyclin complex are critical events driving cell
cycle cell turnover. The regulation of cyclin-dependent protein kinase activation and
inactivation is central to the control of the cell cycle.
CDK family
CDK is a class of cyclin-dependent protein kinases, and the substrate is a
heterodimeric silk/threonine kinase family. So far, the named CDKS family has 13
members: CDK1~CDK13. CDK is activated by binding to cyclins, which catalyze the
phosphorylation of substrates and drive the phase of the cell cycle to complete DNA
synthesis and mitosis, leading to cell growth and proliferation. At the same time,
CDKs can also play a negative regulatory role in combination with CDKs inhibitory
factor (CKI), inhibit cell cycle progression and prevent cell division. In the different
cell cycle phases, the main controlling G1 phase is CDK2, 4 and 6, and the S phase
and G2 phase are dependent on CDK2, while the M phase is mainly regulated by
CDK1. In view of the important role of CDK2 activity abnormality in tumorigenesis
and development, CDK2 inhibitors have become a new direction in tumor treatment
research. Studies have shown that direct inhibition of CDK2 kinase activity or
inhibition of CDK2 by enhancing p27 and p21 can cause growth inhibition of ovarian
cancer cells. Cyclin is a family of positive regulatory proteins and is an active factor of
CDK.
