p21 is a potent cyclin-dependent kinase inhibitor (CKI). The p21 (CIP1/WAF1) protein binds to and inhibits the activity of cyclin-CDK2, -CDK1, and -CDK4 /6 complexes, and thus functions as a regulator of cell cycle progression at G 1 and S phase.

Jun 1, 2016 · Cyclin-dependent kinase (CDK) inhibitor p21 (also known as p21 WAF1/Cip1) is one of these factors that promote cell cycle arrest in response to a variety of stimuli. The inhibitory effect of P21 on cell cycle progression correlates with its nuclear localization.

Mar 31, 2022 · The cyclin-dependent kinase inhibitor p21/WAF1/CIP1/CDKN1A is required for downregulation. RB-E2F complexes bind to promoters of a large fraction of genes repressed by p53 and p21.

p21 or p27 protein is able to interact with cyclin-CDK complexes within the nucleus and hence regulate the cell cycle. p21 and p27 are themselves regulated either by sequestration via cyclin-CDK complexes, or by phosphorylation on serine/threonine …

Apr 4, 1998 · Several lines of evidence suggest that p21 may have an especially important role in CDK2 regulation. In vitro, p21 has a very high affinity for cyclin E/CDK2 complexes (Gu et al., 1993) and >95% of the active CDK2 in normal diploid fibroblasts is found associated with p21 (Harper et al., 1995).

p21Cip1 is a cyclin-dependent kinase (Cdk) inhibitor that is transcriptionally activated by p53 in response to DNA damage. We have explored the interaction of p21 with the currently known Cdks. p21 effectively inhibits Cdk2, Cdk3, Cdk4, and Cdk6 ...

p21 Waf/CIP1 is a small unstructured protein that binds and inactivates cyclin-dependent kinases (CDKs). To this end, p21 levels increase following the activation of the p53 tumor suppressor. CDK inhibition by p21 triggers cell-cycle arrest in the G1 and G2 phases of the cell cycle.

Nov 19, 1993 · CIP1 encodes a novel 21 kd protein that is found in cyclin A, cyclin D1, cyclin E, and Cdk2 immunoprecipitates. p21 CIP1 is a potent, tight-binding inhibitor of Cdks and can inhibit the phosphorylation of Rb by cyclin A-Cdk2, cyclin E …

Dec 15, 2022 · Here we demonstrate that p21 negatively regulates basal autophagy at physiological concentration. Akt activation, upon p21 attenuation, driven ROS accumulation appears to be the major...

Feb 12, 2008 · The CKIs p21, p27, and p57 can repress E2F-mediated transcription indirectly via the inhibition of cyclin-CDK complexes, thereby maintaining Rb-family proteins (Rb/p110, p107, and p130) in a hypophosphorylated state in which they sequester E2F transcription factors.