What are cyclins responsible for in the cell cycle?

Cyclins are crucial proteins that regulate the progression of the cell cycle. They do so by activating cyclin-dependent kinases (CDKs), which are enzymes that drive the process of cell division forward. Each stage of the cell cycle is regulated by specific cyclins that are produced and degraded at particular points during the cycle. For instance, different cyclins are involved in preparing the cell to enter and progress through phases such as G1, S, G2, and mitosis.

The synthesis and degradation of cyclins in a tightly controlled manner ensure that the cell only progresses to the next phase when certain conditions are met, such as proper DNA replication and repair. This regulation helps maintain genomic integrity and prevents uncontrolled cell division, which can lead to issues like cancer.

Thus, the role of cyclins as regulators is integral to the orderly and timely progression through the cell cycle.