Cell cycle: What causes cells to continue dividing?

The cell division cycle has been divided into four phases: G₁, S, G₂, and M phases. A nondividing cell is said to be in G₀. The decision of whether to continue dividing or enter the quiescent G₀ state is made just as G₁ begins.



From studies predominantly done in yeast, we have discovered many proteins that control each of the steps within these phases. Prominent among the controlling molecules are the cyclins, cyclin dependent kinases (CDKs) and CDK inhibitors. Many of the genes that are required for cell cycle control are mutant in cancer cells.

Regulation of the Cell Cycle

	DNA Structure and Function
	DNA Replication
	Transcription
	Transcription Factors
	Signal Transduction
	Cell Cycle