Cyclin E
Encyclopedia
Cyclin E is a member of the cyclin
family.
Cyclin E binds to G1
phase Cdk2, which is required for the transition from G1 to S phase
. The Cyclin E/CDK2 complex phosphorylates
p27Kip1 (an inhibitor
of Cyclin D
), tagging it for degradation, thus promoting expression of Cyclin A
, allowing progression to S phase.
Cyclin
Cyclins are a family of proteins that control the progression of cells through the cell cycle by activating cyclin-dependent kinase enzymes.- Function :...
family.
Cyclin E binds to G1
G1 phase
The G1 phase is a period in the cell cycle during interphase, before the S phase. For many cells, this phase is the major period of cell growth during its lifespan. During this stage new organelles are being synthesized, so the cell requires both structural proteins and enzymes, resulting in great...
phase Cdk2, which is required for the transition from G1 to S phase
S phase
S-phase is the part of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Precise and accurate DNA replication is necessary to prevent genetic abnormalities which often lead to cell death or disease. Due to the importance, the regulatory pathways that govern this...
. The Cyclin E/CDK2 complex phosphorylates
Phosphorylation
Phosphorylation is the addition of a phosphate group to a protein or other organic molecule. Phosphorylation activates or deactivates many protein enzymes....
p27Kip1 (an inhibitor
Enzyme inhibitor
An enzyme inhibitor is a molecule that binds to enzymes and decreases their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used as herbicides and pesticides...
of Cyclin D
Cyclin D
Cyclin D is a member of the cyclin protein family that is involved in regulating cell cycle progression. The synthesis of cyclin D is initiated during G1 and drives the G1/S phase transition...
), tagging it for degradation, thus promoting expression of Cyclin A
Cyclin A
Cyclin A is a member of the cyclin family.Cyclin A binds to S phase Cdk2 and is required for the cell to progress through the S phase. Cyclin A/ Cdk2 is inhibited by the complex p21CIP.-External links:*...
, allowing progression to S phase.