Cyclin-Dependent Kinase Inhibitor 1a (CDKN1A) Human Recombinant Protein

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. Multiple alternatively spliced variants have been found for this gene. [provided by RefSeq, Nov 2010]

p21Cip1: a cell-cycle regulatory protein that Interacts with cyclin-CDK2 and -CDK4, inhibiting cell cycle progression at G1. Its expression is tightly controlled by p53, through which this protein mediates the p53-dependent cell cycle arrest at G1 phase.

Protein type: Inhibitor; Cell cycle regulation

Chromosomal Location of Human Ortholog: 6p21.2

Cellular Component: nucleoplasm; intracellular membrane-bound organelle; perinuclear region of cytoplasm; cyclin-dependent protein kinase holoenzyme complex; nucleus; cytosol

Molecular Function: cyclin-dependent protein kinase inhibitor activity; cyclin binding; protein binding; cyclin-dependent protein kinase activating kinase activity; ubiquitin protein ligase binding; metal ion binding; protein complex binding

Biological Process: nerve growth factor receptor signaling pathway; response to arsenic; response to toxin; DNA damage response, signal transduction by p53 class mediator resulting in cell cycle arrest; protein amino acid phosphorylation; negative regulation of cell proliferation; positive regulation of fibroblast proliferation; positive regulation of B cell proliferation; G2/M transition of mitotic cell cycle; cell cycle arrest; DNA damage response, signal transduction by p53 class mediator resulting in induction of apoptosis; response to corticosterone stimulus; response to X-ray; epidermal growth factor receptor signaling pathway; response to drug; organ regeneration; phosphoinositide-mediated signaling; fibroblast growth factor receptor signaling pathway; negative regulation of cyclin-dependent protein kinase activity; response to organic nitrogen; positive regulation of programmed cell death; response to hyperoxia; positive regulation of protein kinase activity; Ras protein signal transduction; cellular response to extracellular stimulus; regulation of protein import into nucleus, translocation; negative regulation of phosphorylation; innate immune response; negative regulation of cell growth; mitotic cell cycle; regulation of cyclin-dependent protein kinase activity; response to DNA damage stimulus; G1/S transition of mitotic cell cycle; negative regulation of apoptosis