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PhosphoSitePlus® Resource

  • Additional protein information
  • Analytical tools


Product Includes Quantity Applications Reactivity MW(kDa) Isotype
c-Fos Antibody 4384 20 µl
Western Blotting
H M R 62 Rabbit 
Phospho-c-Fos (Ser32) (D82C12) XP® Rabbit mAb 5348 20 µl
Western Blotting Immunoprecipitation Immunofluorescence Flow Cytometry Chromatin Immunoprecipitation
H M R 62 Rabbit IgG
FosB (5G4) Rabbit mAb 2251 20 µl
Western Blotting Immunoprecipitation Immunohistochemistry Immunofluorescence Flow Cytometry Chromatin Immunoprecipitation
H M R 38 FosB2 48 FosB Rabbit IgG
FRA1 (D80B4) Rabbit mAb 5281 20 µl
Western Blotting Immunoprecipitation
H 40 Rabbit IgG
Phospho-FRA1 (Ser265) (D22B1) Rabbit mAb 5841 20 µl
Western Blotting Chromatin Immunoprecipitation
H M R 40 Rabbit IgG
Anti-rabbit IgG, HRP-linked Antibody 7074 100 µl
Western Blotting

Product Description

The Fos Family Antibody Sampler Kit provides an economical means to evaluate the Fos family of transcription factors. The kit includes enough antibody to perform two western blot experiments with each primary antibody.

Specificity / Sensitivity

Each antibody in the Fos Family Antibody Sampler Kit recognizes endogenous levels of the specific target protein. FosB (5G4) Rabbit mAb detects both FosB and FosB2 isoforms. Phospho-FRA1 (Ser265) (D22B1) Rabbit mAb recognizes endogenous levels of FRA1 protein only when phosphorylated at Ser265. This antibody may also cross-react with phospho-FRA2, but does not cross-react with phospho-c-Fos or phospho-FosB.

Source / Purification

Monoclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser32 of human c-Fos, Ser265 of human FRA1 protein or with a synthetic peptide derived from human FosB, or FRA1.

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to amino acids near the carboxy-terminus of human c-Fos 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).

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.

Entrez-Gene Id 2353 , 2354 , 8061
Swiss-Prot Acc. P01100 , P53539 , P15407

For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.

Fos Family Antibody Sampler Kit