The regulation of the cell cycle

Learn more about the regulation of cyclins during the cell cycle with our poster

Pioneering work by Paul Nurse and Leland Hartwell identified genetic mutants that regulate cell cycle progression in Saccharomyces pombe and Saccharomyces cerevisiae respectively. Furthermore, the discovery of maturation-promoting factor in Xenopus laevis by Yoshio Masui together with the identification of cyclins in sea urchin eggs by Tim Hunt led to the discovery of key components that regulate the cell cycle. In 2001, Paul Nurse, Leland Hartwell, and Tim Hunt received the Nobel prize in physiology or medicine for their contribution to the understanding of cell cycle regulation (Pulverer, 2001).

The mammalian cell cycle can be divided into the four distinct phases Gap 1 (G1), synthesis (S), Gap 2 (G2), and mitosis (M phase) which require three ‘switch-like’ transitions to regulate S phase entry, mitotic entry, and the exit of mitosis (Hochegger et al., 2008). Mitosis is subdivided into a further six phases including prophase, pro-metaphase, metaphase, anaphase, telophase, and cytokinesis which control nuclear envelope breakdown (NEBD), the attachment of chromosomes to spindle poles, the alignment of chromosomes upon the metaphase plate, the separation of sister chromatids and the separation of the cell into two daughter cells respectively.