What is the role of CDK in cell cycle regulation?

CDK, or cyclin-dependent kinase, plays a crucial role in cell cycle regulation. CDK is an enzyme that, when activated, phosphorylates specific target proteins, thereby controlling the progression of the cell cycle. CDK activity is dependent on the binding of cyclin proteins, which undergo periodic fluctuations during the cell cycle.

CDKs are responsible for the transition from one phase of the cell cycle to the next by phosphorylating key proteins involved in cell cycle regulation. These phosphorylation events trigger various downstream signaling cascades that regulate processes such as DNA replication, chromosome segregation, and cell division.

The activation and inactivation of different CDK-cyclin complexes at specific points in the cell cycle ensure proper coordination and timing of cell cycle events. CDK activity is tightly regulated by several mechanisms, including the synthesis and degradation of cyclins, binding of inhibitory proteins, and phosphorylation status. Dysregulation of CDK activity can lead to cell cycle abnormalities and contribute to conditions such as cancer.