Cell Signaling Technology

Product Pathways - Cell Cycle / Checkpoint

p21 Waf1/Cip1 (12D1) Rabbit mAb (Biotinylated) #8831

Applications Reactivity Sensitivity MW (kDa) Isotype
W H Mk Endogenous 21 Rabbit

Applications Key:  W=Western Blotting
Reactivity Key:  H=Human  Mk=Monkey
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

p21 Waf1/Cip1 (12D1) Rabbit mAb (Biotinylated) detects endogenous levels of total p21 protein. The antibody does not cross-react with other CDK inhibitors.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues near the carboxy terminus of human p21 protein.

Western Blotting

Western Blotting

Western blot analysis of extracts from COS-7, HeLa, and MCF7 cells using p21 Waf1/Cip1 (12D1) Rabbit mAb (Biotinylated). Streptavidin-HRP #3999 was used for detection.

Description

This Cell Signaling Technology antibody is conjugated to biotin under optimal conditions. The biotinylated antibody is expected to exhibit the same species cross-reactivity as the unconjugated p21 Waf1/Cip1 (12D1) Rabbit mAb #2947.

Background

The tumor suppressor protein p21 Waf1/Cip1 acts as an inhibitor of cell cycle progression. It functions in stoichiometric relationships forming heterotrimeric complexes with cyclins and cyclin-dependent kinases. In association with CDK2 complexes, it serves to inhibit kinase activity and block progression through G1/S (1). However, p21 may also enhance assembly and activity in complexes of CDK4 or CDK6 and cyclin D (2). The carboxy-terminal region of p21 is sufficient to bind and inhibit PCNA, a subunit of DNA polymerase, and may coordinate DNA replication with cell cycle progression (3). Upon UV damage or during cell cycle stages when cdc2/cyclin B or CDK2/cyclin A are active, p53 is phosphorylated and upregulates p21 transcription via a p53-responsive element (4). Protein levels of p21 are downregulated through ubiquitination and proteasomal degradation (5).

  1. Pestell, R.G. et al. (1999) Endocrine Rev. 20, 501-534.
  2. Cheng, J. et al. (1999) EMBO J. 18, 1571-1583.
  3. Flores-Rozas, H. et al. (1994) Proc. Natl. Acad. Sci. USA 91, 8655-8659.
  4. Wang, Y. and Prives, C. (1995) Nature 376, 88-91.
  5. Sheaff, R.J. et al. (2000) Cell 5, 403-410.

Application References

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Companion Products

Rabbit monoclonal antibody is produced under license (granting certain rights including those under U. S. Patents No. 5,675,063 and 7,429,487) from Epitomics, Inc.

For Research Use Only. Not For Use In Diagnostic Procedures.

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