NEET BIOLOGY

Detailed explanation-1: -In order to drive the cell cycle forward, a cyclin must activate or inactivate many target proteins inside of the cell. Cyclins drive the events of the cell cycle by partnering with a family of enzymes called the cyclin-dependent kinases (Cdks).

Detailed explanation-2: -Cdk (cyclin dependent kinase, adds phosphate to a protein), along with cyclins, are major control switches for the cell cycle, causing the cell to move from G1 to S or G2 to M. MPF (Maturation Promoting Factor) includes the CdK and cyclins that triggers progression through the cell cycle.

Detailed explanation-3: -Cyclins: Key Components of the Cell Cycle Machinery The cyclins are regulatory subunits that bind, activate and provide substrate specificity for their catalytic partner serine-threonine kinases, collectively called cyclin-dependent kinases (Cdks) (reviewed in refs. 8 and 9).

Detailed explanation-4: -Cyclins are the regulatory subunits of kinases that control progress through the cell cycle. This review focuses on cyclins that are targets for extracellular signaling and frequently deregulated during oncogenesis, particularly cyclin D1.

Detailed explanation-5: -The formation of cyclin/CDKs controls the cell-cycle progression via phosphorylation of the target genes, such as tumor suppressor protein retinoblastoma (Rb). The activation of cyclins/CDKs is induced by mitogenic signals and inhibited by the activation of cell-cycle checkpoints in response to DNA damage [8].