p21

Cyclin-dependent kinase inhibitor 1A (p21, Cip1), also known as CDKN1A, is a human gene.

Cyclin-dependent kinase inhibitor 1A (p21, Cip1)
Identifiers
Symbols	CDKN1A ; CAP20; CDKN1; CIP1; MDA-6; P21; SDI1; WAF1; p21CIP1
External IDs	Template:OMIM5 Template:MGI HomoloGene: 333
Gene ontology Molecular function Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Cellular component Template:GNF GO Template:GNF GO Biological process Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO
RNA expression pattern
File:PBB GE CDKN1A 202284 s at.png
More reference expression data
Orthologs
Template:GNF Ortholog box
Species	Human	Mouse
Entrez	n/a	n/a
Ensembl	n/a	n/a
UniProt	n/a	n/a
RefSeq (mRNA)	n/a	n/a
RefSeq (protein)	n/a	n/a
Location (UCSC)	n/a	n/a
PubMed search	n/a	n/a

This gene encodes a potent cyclin-dependent kinase inhibitor. The encoded protein binds to and inhibits the activity of cyclin-CDK2 or -CDK4 complexes, and thus functions as a regulator of cell cycle progression at G1. The expression of this gene is tightly controlled by the tumor suppressor protein p53, through which this protein mediates the p53-dependent cell cycle G1 phase arrest in response to a variety of stress stimuli. This protein can interact with proliferating cell nuclear antigen (PCNA), a DNA polymerase accessory factor, and plays a regulatory role in S phase DNA replication and DNA damage repair. This protein was reported to be specifically cleaved by CASP3-like caspases, which thus leads to a dramatic activation of CDK2, and may be instrumental in the execution of apoptosis following caspase activation. Two alternatively spliced variants, which encode an identical protein, have been reported.

p21, also known as cyclin-dependent kinase inhibitor 1A or CDKN1A, is a human gene on chromosome 6 (location 6p21.2), that encodes a cyclin-dependent kinase inhibitor that directly inhibits the activity of cyclin-CDK2 and cyclin-CDK4 complexes. p21 functions as a regulator of cell cycle progression at G1 phase. The expression of p21 is controlled by the tumor suppressor protein p53.

The function of this gene relates in part to stress response .

p21 is also mediating the resistance of hematopoietic cells to an infection with HIV by complexing with the HIV integrase and thereby aborting chromosomal integration of the provirus.

External links

• Cyclin-Dependent+Kinase+Inhibitor+p21 at the US National Library of Medicine Medical Subject Headings (MeSH)

Further reading

• Marone M, Bonanno G, Rutella S; et al. (2003). "Survival and cell cycle control in early hematopoiesis: role of bcl-2, and the cyclin dependent kinase inhibitors P27 and P21". Leuk. Lymphoma. 43 (1): 51–7. PMID 11908736.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Fang JY, Lu YY (2002). "Effects of histone acetylation and DNA methylation on p21( WAF1) regulation". World J. Gastroenterol. 8 (3): 400–5. PMID 12046058.
• Tokumoto M, Tsuruya K, Fukuda K; et al. (2003). "Parathyroid cell growth in patients with advanced secondary hyperparathyroidism: vitamin D receptor and cyclin-dependent kinase inhibitors, p21 and p27". Nephrol. Dial. Transplant. 18 Suppl 3: iii9–12. PMID 12771291.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Amini S, Khalili K, Sawaya BE (2004). "Effect of HIV-1 Vpr on cell cycle regulators". DNA Cell Biol. 23 (4): 249–60. doi:10.1089/104454904773819833. PMID 15142382.CS1 maint: Multiple names: authors list (link)
• Zhang Z, Wang H, Li M; et al. (2006). "Novel MDM2 p53-independent functions identified through RNA silencing technologies". Ann. N. Y. Acad. Sci. 1058: 205–14. doi:10.1196/annals.1359.030. PMID 16394138.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)