Cyclin-dependent kinase–cyclin complex (CDK–cyclin complex)

The term "cell cycle regulatory machinery" refers to a network of molecular complexes that govern the orderly progression and timing of the eukaryotic cell cycle. The core of this machinery comprises cyclin-dependent kinases (CDKs; serine/threonine kinases) and their essential regulatory subunits, the cyclins. These kinase–cyclin complexes act as master integrators of intracellular and extracellular signals to ensure sequential activation of cell cycle events, such as DNA synthesis, mitosis, and cell division. Additional control is exerted by checkpoint proteins (such as p53, Rb, and p21), ubiquitin ligases (APC/C, SCF complex), and other kinases (Aurora kinase, Polo-like kinase). Dysregulation of these components—most commonly through overexpression or mutation—drives uncontrolled cell proliferation, a hallmark of many cancers. Consequently, specific CDKs (especially CDK4/6) are established therapeutic targets in oncology[1][2][3][5][6][7].

Other names

cell-cycle control systemcell cycle regulatorscyclin–CDK complexescell cycle checkpoint machinerycyclin-dependent kinaseCDKcyclin

Inhibition of CDK enzymatic activity, leading to cell cycle arrest (typically G1/S arrest). Induction of apoptosis in rapidly dividing cells. Blockage of S phase entry or mitosis.