Cell Signaling Technology

Product Pathways - MAPK Signaling

FosB (5G4) Rabbit mAb (Alexa Fluor® 488 Conjugate) #2023

Applications Reactivity Sensitivity Isotype
F H M R Endogenous Rabbit IgG

Applications Key:  F=Flow Cytometry
Reactivity Key:  H=Human  M=Mouse  R=Rat
Species cross-reactivity is determined by Western blot.

Specificity / Sensitivity

FosB (5G4) Rabbit mAb (Alexa Fluor® 488 Conjugate) 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

Monoclonal antibody is produced by immunizing animals with a synthetic peptide (KLH-coupled) derived from the sequence of human FosB. The antibody was conjugated to Alexa Fluor® 488 under optimal conditions with an F/P ratio of 2-6.

Flow Cytometry

Flow Cytometry

Flow cytometric analysis of HeLa cells, untreated (blue) or treated with TPA (green), using FosB (5G4) Rabbit mAb (Alexa Fluor® 488 Conjugate).

Description

This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct flow cytometric analysis of human cells. The unconjugated antibody FosB (5G4) Rabbit mAb #2251 reacts with human, mouse and rat FosB protein. CST expects that FosB (5G4) Rabbit mAb (Alexa Fluor® 488 Conjugate) will also recognize FosB in these species.

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

Alexa Fluor® is a registered trademark of Molecular Probes, Inc.Rabbit Monoclonals Produced Using Epitomics® Technology, U.S. Patent No. 5,675,063.

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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