Question

8. The primary mechanism by which cells exit from the M phase of the cell cycle is through a. ubiquitin-dependent proteolysis of M-phase kinases b. activation of the anaphase-promoting complex c. activation of the condensin complex d. degradation of p53 e. none of the above

Answer 1

The answer is a) ubiquitin-dependent proteolysis of M phase kinases

The cell cycle is an orderly programmed event in which a cell replicates into two. cell cycle control is crucial for the healthy generation of the new functional cells. Cyclins and cyclin-dependent kinases (Cdks) are the important cell control systems. at various phases of cell cycle i.e., M phase, G1 phase, S phase and G2 phase. Cdks are the key regulators of cell cycle and act under the control of cyclins.

During M phase, M cyclins play a crucial role in progressing mitosis (division phase of the cell). At the end of the M phase, to exit from cell division, M cyclins get degraded by Cdc20-APC complex mediated ubiquitin-dependent proteolysis