syklins

Cyclins are a group of proteins that regulate the cell cycle. They are named for their cyclical production and degradation that occurs during different phases of the cell cycle. Cyclins act by binding to and activating cyclin-dependent kinases (CDKs), which are enzymes that phosphorylate other proteins. These phosphorylation events are crucial for driving the cell cycle forward through its various checkpoints. Different cyclins are produced and degraded at specific times, ensuring that cell cycle progression occurs in a controlled and ordered manner. For example, cyclin D is typically associated with the G1 phase, cyclin E with the transition from G1 to S phase, cyclin A with the S phase, and cyclins B and A with the G2 and M phases. The precise timing and levels of cyclin activity are tightly regulated to prevent errors in DNA replication or chromosome segregation. Dysregulation of cyclin activity can lead to uncontrolled cell proliferation, a hallmark of cancer. Therefore, cyclins play a fundamental role in maintaining genomic stability and preventing disease.