What is the role of cyclin in regulating the cell cycle?

Cyclin plays a crucial role in regulating the cell cycle by activating cyclin-dependent kinases (cdks). Cyclins are a group of proteins whose concentrations fluctuate throughout the cell cycle, and their primary function is to bind to and activate cdks. This activation leads to the phosphorylation of target proteins that are essential for progressing through different phases of the cell cycle, such as the transition from G1 to S phase, and from G2 to M phase.

The formation of the cyclin-cdk complex allows the cell to move forward in the cell cycle in a controlled manner. Without cyclin, cdks remain inactive, and the cell cannot progress through the cycle, which emphasizes the importance of cyclin in mediating cell cycle regulation. The precise control of cyclin levels at specific times ensures that cell division occurs correctly and in response to the cell’s growth signals and conditions.