Cyclin

Cyclins are proteins that help regulate the cell cycle—the process by which cells grow and divide. They act like switches, turning on specific signals that instruct the cell when to progress through different phases of division. As the cell prepares to divide, cyclins increase in concentration, bind to other proteins called cyclin-dependent kinases (CDKs), and activate them. This activation triggers necessary actions for cell division, such as DNA replication and chromosome separation. Once their job is done, cyclin levels decrease, ensuring the cycle progresses smoothly and cells divide properly.