User:JonSDSUGrad/Sandbox/TEST5 CDKN1A

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cyclin-dependent kinase inhibitor 1A (p21
Identifiers
Symbol(s)	CDKN1A; CAP20; CDKN1; CIP1; MDA-6; P21; SDI1; WAF1; p21CIP1
External IDs	OMIM: 116899 MGI: 104556 HomoloGene: 333
Gene ontology Molecular Function: • cyclin-dependent protein kinase holoenzyme complex • protein kinase activity • cyclin-dependent protein kinase inhibitor activity • nucleus • response to DNA damage stimulus • cell cycle • cell cycle arrest • zinc ion binding • negative regulation of cell proliferation • induction of apoptosis by intracellular signals • response to UV • kinase activity • cyclin binding • positive regulation of B cell proliferation • negative regulation of apoptosis • positive regulation of non-apoptotic programmed cell death • negative regulation of cyclin-dependent protein kinase activity • metal ion binding
Orthologs
	Human	Mouse
Entrez	1026	12575
Ensembl	ENSG00000124762	ENSMUSG00000023067
Uniprot	P38936	n/a
Refseq	NM_000389 (mRNA) NP_000380 (protein)	NM_007669 (mRNA) NP_031695 (protein)
Location	Chr 6: 36.75 - 36.76 Mb	Chr 17: 28.82 - 28.83 Mb
Pubmed search	[1]	[2]

[edit] Summary

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.