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Product Usage Information

Storage: Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA and 50% glycerol. Store at –20°C. Do not aliquot the antibody.

Specificity / Sensitivity

Delta FosB Antibody recognizes endogenous levels of total Delta FosB and Delta2 Delta FosB proteins. This antibody does not cross-react with FosB.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues near the carboxy terminus of human Delta FosB protein. Antibodies are purified by protein A and peptide affinity chromatography.

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 (Delta FosB), which lacks the carboxy-terminal 101 amino acids (1-3). 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 Fos proteins by Erk kinases in response to extracellular stimuli may further increase transcriptional activity (4-6). Phosphorylation of c-Fos at Ser32 and Thr232 by Erk5 increases protein stability and nuclear localization (5). Phosphorylation of FRA1 at Ser252 and Ser265 by Erk1/2 increases protein stability and leads to overexpression of FRA1 in cancer cells (6). Following growth factor stimulation, expression of FosB and c-Fos in quiescent fibroblasts is immediate, but very short-lived, with protein levels dissipating after several hours (7). FRA1 and FRA2 expression persists longer, and appreciable levels can be detected in asynchronously growing cells (8). Deregulated expression of c-Fos, FosB, or FRA2 can result in neoplastic cellular transformation; however, Delta FosB lacks the ability to transform cells (2,3).

Delta FosB is encoded by the FosB gene and is produced by alternative splicing. It lacks the 101 C-terminal residues of FosB, a region containing ubiquitination sites, hence conferring higher stability to Delta FosB (9). Delta FosB is induced and accumulates in select brain regions upon chronic drug use (10-12), where it interacts with JunD to form an active long-lasting AP-1 complex (13). This complex has been proposed to represent a molecular switch that helps initiate and maintain the addicted state (14,15).

1.  Tulchinsky, E. (2000) Histol Histopathol 15, 921-8.

2.  Dobrazanski, P. et al. (1991) Mol Cell Biol 11, 5470-8.

3.  Nakabeppu, Y. and Nathans, D. (1991) Cell 64, 751-9.

4.  Rosenberger, S.F. et al. (1999) J Biol Chem 274, 1124-30.

5.  Sasaki, T. et al. (2006) Mol Cell 24, 63-75.

6.  Basbous, J. et al. (2007) Mol Cell Biol 27, 3936-50.

7.  Kovary, K. and Bravo, R. (1991) Mol Cell Biol 11, 2451-9.

8.  Kovary, K. and Bravo, R. (1992) Mol Cell Biol 12, 5015-23.

9.  Carle, T.L. et al. (2007) Eur J Neurosci 25, 3009-19.

10.  Hope, B.T. et al. (1994) Neuron 13, 1235-44.

11.  Nye, H.E. et al. (1995) J Pharmacol Exp Ther 275, 1671-80.

12.  Nye, H.E. and Nestler, E.J. (1996) Mol Pharmacol 49, 636-45.

13.  Chen, J. et al. (1997) J Neurosci 17, 4933-41.

14.  Nestler, E.J. et al. (2001) Proc Natl Acad Sci U S A 98, 11042-6.

15.  McClung, C.A. et al. (2004) Brain Res Mol Brain Res 132, 146-54.

Entrez-Gene Id 2354
Swiss-Prot Acc. P53539

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