c-Fos, rabbit polyclonal, Cat# RPCA-c-Fos-AP

c-Fos, rabbit polyclonal, Cat# RPCA-c-Fos-AP

Left: RPCA-c-Fos-AP staining (red) in HeLa cells which were treated with serum-starvation for 36 hours, followed by 2 hours, 20% FBS stimulation (bottom panel), or followed by PBS treatment (top panel). Red c-Fos staining only localizes in the nuclei of stimulated cells, but not in un-stimulated cells. Cells were counterstained with our chicken polyclonal antibody against vimentin, CPCA-Vim (green). Blue shows DAPI staining of nuclear DNA.Middle: Mouse brain section (45 μM; fixed by transcardial perfusion with 4% paraformaldehyde) labeled with RPCA-c-Fox-AP using a standard HRP-DAB staining technique. Cells expressing c-Fos appear to be dark. Right: Mouse brain section across hippocampus labeled with RPCA-c-Fos-AP (red) and our anti Fox3/NeuN (MCA-1B7) antibody (green) using immuno-fluorescent microscopy. Neurons positive for c-Fos and Fox3/NeuN appear to be yellow. Inset shows an enlarged image of RPCA-c-Fos-AP staining. Nuclei are labeled with Dapi (blue). For more images of stimulated and non-stimulated cells and tissues stained with RPCA-c-Fos-AP and our monoclonal antibody to c-Fos, MCA-2H2 press here.

Top panel : Western blot analysis of c-Fos expression HeLa cells with RPCA-c-Fos-AP. 1: HeLa cells were serum-starved for 36 hours 2: Serum-starved HeLa cells were stimulated with 20% FBS (fetal bovine serum) for 2 hours.RPCA-c-Fos-AP recognizes bands with apparent molecular weight of 50-65 kDa, representing multiple forms of the c-Fos protein. These bands appear in serum stimulated cells and are absent in serum-starved HeLa cells. Bottom panel: Blot was stripped and probed with EnCor monoclonal antibody against GAPDH: MCA-1D4, used as loading control.

Product name Anti-c-Fos
Description Rabbit polyclonal to c-Fos
Reference Code RPCA-c-Fos-AP
RRID# AB_2572236
Molecular weight 50-65 kDa
Immunogen Full length recombinant human protein expressed in and purified from E. coli.
Concentration Antibody is supplied as an aliquot of 1 mg/mL of affinity purified antibody
Species Reactivity Human, horse, cow, pig, chicken, rat, mouse
Applications Western blot, ICC/IF, IHC
Suggestions for use Western blots: 1:1,000-1:2,000
ICC/IF or IHC: 1:5,000

c-Fos is a member of Fos family of transcription factors and is a cellular counterpart of the retroviral oncogene: v-Fos. Others member of Fos family is FosB, Fra-1 and Fra-2. Fos proteins associate with Jun family members, but also with other basic leucine-zipper (bZIP) proteins to create a variety of AP-1 (activator protein-1) complexes (1). Dimeric AP-1 complexes regulate major physiological processes such as cell proliferation, differentiation, neoplastic transformation, apoptosis, and response to stress.

c-Fos and c-Jun are the best-studied AP-1 components. They share a number of homologous domains, including adjacent basic and leucine zipper motifs, necessary for binding to DNA and dimerization, respectively. c-Fos and c-Jun-containing AP-1 dimers activate transcription by direct contacts with coactivators, such as the CBP (3), and constituents of the basal transcription machinery, such as the TATA-binding protein (4).

c-Fos is expressed constitutively in certain tissues. However, they are considered immediate-early genes because their expression is usually low but inducible rapidly and transiently in response to a wide array of stimuli including serum, growth factors, tumor promoters, cytokines, and UV radiation to allow cells to adapt to environmental changes. It plays an important role in many cellular functions and has been found to be overexpressed in a variety of cancers.

c-Fos is subjected to different modification: phosphorylation activates c-Fos, whereas sumoylation of c-Fos inhibits the AP-1 transcriptional activity (5,6). Several lines of data demonstrate expression of c-Fos by individual neurons can be used as a marker of cell activation, due to association of c-Fos expression with neurons fire action potentials (7,8,9,10). The HGNC name for this protein is FOS.

Antibody was raised in rabbit against full length recombinant protein expressed in and purified from E. coli. The antibody is affinity purified and diluted in PBS.



1. Mildle-Langosch K. The Fos family of transcription factors and their role in tumourigenesis. European Journal of Cancer 41(16), 2449-2461 (2005).

2. Chiu R, Boyle WJ, Meek J, Smeal T, Hunter T, Karin M. The c-Fos protein interacts with c-Jun/AP-1 to stimulate transcription of AP-1 responsive genes. Cell 54 (4): 541–52. (1988)

3. Bannister AJ and Kouzarides T. CBP-induced stimulation of c-Fos activity is abrogated by ElA. The EMBO Journal 14 (19): 4758-4762 (1995).

4. Metz R, Bannister AJ, Sutherland JA, Hagemeier C, O’Rourke EC, Cook A, Bravo R, Kouzarides T. c-Fos-induced activation of a TATA-box-containing promoter involves direct contact with TATA-box-binding protein. Mol Cell Biol.14(9):6021-9 (1994).

5. Karin M. The regulation of AP-1 activity by mitogen activated protein kinases. J Biol Chem. 270(28):16483-6 (1995).

6. Bossis G, Malnou CE, Farras R, Andermarcher E, Hipskind R, Rodriguez M, Schmidt D, Muller S, Jariel-Encontre I, Piechaczyk M. Down-regulation of c-Fos/c-Jun AP-1 dimer activity by sumoylation. Mol Cell Biol.25(16):6964-79 (2005).

7. Day HE, Kryskow EM, Nyhuis TJ, Herlihy L, Campeau S. Conditioned Fear Inhibits c-fos mRNA Expression in the Central Extended Amygdala. Brain Res.1229: 137–46 (2008).

8. Hoffman G, Smith MS, Verbalis JG. c-Fos and related immediate early gene products as markers of activity in neuroendocrine systems. Fronties in Neuroendocrinology. 14(3):173-213 (1993 )

9. Van Elzakker M, Fevurly RD, Breindel T, Spencer RL. Environmental novelty is associated with a selective increase in Fos expression in the output elements of the hippocampal formation and the perirhinal cortex. Learn. Mem. 15 (12): 899–908 (2008).

10: Dragunow M, Faull R. The use of c-fos as a metabolic marker in neuronal pathway tracing. Journal of Neuroscience Methods 29 (3): 261–265 (1989).

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