Cell Cycle: The Life Cycle of a Cell

Abstract

“Where a cell arises, there must be a previous cell”. This early statement of Rudolf Virchow already points to the process that is called cell cycle. It describes a series of events leading to cell division and duplication and can be sectioned into phases that are controlled by a collection of proteins interacting with each other, the cyclines and the cycline-dependent kinases. It is mandatory that DNA replication is conservative meaning that its structure and sequence remain unaltered while the DNA is duplicated before the cell actually divides. Checkpoints are responsible for the supervision, proteins such as p53 and RB being the key protagonists in cell cycle control. Upon DNA damage recognized repair programs are activated or if repair fails the cell is driven into a programmed cell death to remove the damaged cell. The transfer of DNA mistakes from the mother cell to the daughter cells can lead to tumor formation. So p53 and RB are key tumor suppressor proteins.