Cell Signaling Technology

Product Pathways - MAPK Signaling

FosB Antibody #2263

Applications Reactivity Sensitivity MW (kDa) Source
W IP IF-IC H M R Endogenous 38 FosB2. 48 FosB. Rabbit

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  IF-IC=Immunofluorescence (Immunocytochemistry)
Reactivity Key:  H=Human  M=Mouse  R=Rat
Species cross-reactivity is determined by Western blot.

Specificity / Sensitivity

This antibody detects endogenous levels of total FosB protein (both FosB and FosB2 isoforms). The antibody does not cross-react with other Fos proteins, including c-fos, FRA1 and FRA2.

Source / Purification

Polyclonal antibodies are produced by immunizing rabbits with a synthetic peptide (KLH-coupled) derived from the sequence of human FosB. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from HeLa cells serum-starved overnight and TPA-stimulated for 4 hours or NIH/3T3 cells serum-starved overnight and serum-stimulated for 4 hours, using FosB Antibody.

IF-IC

IF-IC

Immunofluorescent analysis of paraformaldehyde-fixed HeLa cells starved overnight (left panels) and stimulated for 4 hours with TPA (right panels). Cells were stained with DAPI (upper panels) and analyzed by IF using FosB Antibody (lower panels).

Background

The Fos family of nuclear oncogenes includes c-Fos, FosB, fos-related antigen 1 (FRA1) and fos-related antigen 2 (FRA2) (1). While most Fos proteins exist as a single isoform, the FosB protein exists as two isoforms: full-length FosB and a shorter form FosB2/SF that lacks the carboxy-terminal 101 amino acids (1,2). The expression of Fos proteins is rapidly and transiently induced by a variety of extracellular stimuli, including growth factors, cytokines, neurotransmitters, polypeptide hormones and stress. Fos proteins dimerize with Jun proteins (c-Jun, JunB and JunD) to form Activator Protein-1 (AP-1), a transcription factor that binds to TRE/AP-1 elements and activates transcription. Fos and Jun proteins contain the leucine-zipper motif that mediates dimerization and an adjacent basic domain that binds to DNA. The various Fos/Jun heterodimers differ in their ability to transactivate AP-1 dependent genes. In addition to increased expression, phosphorylation of FosB and c-Fos by ERK1/2 in response to extracellular stimuli may further increase transcriptional activity (4). Expression of FosB and c-Fos in quiescent fibroblasts after growth factor stimulation is immediate, but very short-lived, with protein levels dissipating after several hours (5). However, FRA1 and FRA2 expression persists longer and appreciable levels can be detected in asynchronously growing cells (6). Deregulated expression of c-Fos, FosB, or FRA2 can result in neoplastic cellular transformation; however, FosB2 lacks the ability to transform cells (2,3).

  1. Tulchinsky, E. (2000) Histol. Histopathol. 15, 921-928.
  2. Dobrzanski, P. et al. (1991) Mol. Cell. Biol. 11, 5470-5478.
  3. Nakabeppu, Y. and Nathans, D. (1991) Cell 64, 751-759.
  4. Rosenberger, S.F. et al. (1999) J. Biol. Chem. 274, 1124-1130.
  5. Kovary, K. and Bravo, R. (1991) Mol. Cell. Biol. 11, 2451-2459.
  6. Kovary, K. and Bravo, R. (1992) Mol. Cell. Biol. 12, 5015-5023 .

Application References

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Companion Products

This product is for in vitro research use only and is not intended for use in humans or animals. This product is not intended for use as therapeutic or in diagnostic procedures.

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