Cell Signaling Technology

Product Pathways - Cell Cycle / Checkpoint

p21 Waf1/Cip1 (12D1) Rabbit mAb (Alexa Fluor® 488 Conjugate) #5487

Applications Reactivity Sensitivity Isotype
IF-IC F H Mk Endogenous Rabbit IgG

Applications Key:  IF-IC=Immunofluorescence (Immunocytochemistry)  F=Flow Cytometry
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 (Alexa Fluor® 488 Conjugate) 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.

Flow Cytometry

Flow Cytometry

Flow cytometric analysis of COS-7 cells using p21 Waf1/Cip1 (12D1) Rabbit mAb (Alexa Fluor® 488 Conjugate). Red=positive cells.

IF-IC

IF-IC

Confocal immunofluorescent analysis of MCF7 cells using p21 Waf1/Cip1 (12D1) Rabbit mAb (Alexa Fluor® 488 Conjugate) (green). Actin filaments were labeled with DY-554 phalloidin (red). Blue pseudocolor = DRAQ5® #4084 (fluorescent DNA dye).

Description

This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in monkey cells. The 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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For Research Use Only. Not For Use In Diagnostic Procedures.

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