Final answer:
The proteins phosphorylated by Cdks to progress the cell cycle must be dephosphorylated and the cyclins degraded for a cell to exit the M phase. This is essential for the proper sequence of cell cycle events.
Step-by-step explanation:
Exiting the M Phase in Cell Cycle
To move out of the M phase of the cell cycle, the proteins that have been phosphorylated by Cyclin-dependent kinases (Cdks) must be dephosphorylated. This dephosphorylation process typically occurs after the M checkpoint has been passed, leading to the activation of proteolytic enzymes that degrade the cyclin component of the Cdk/cyclin complex. The degradation of cyclins ensures that Cdk activity decreases, thus allowing the cell to exit mitosis. This regulatory mechanism is crucial for the proper progression of the cell cycle and ensures that each subsequent phase is initiated only after the correct completion of the current phase.