• Nature
  • Source
    Baculovirus infected Sf9 cells
  • Amino Acid Sequence
    • Species
    • Tags
      GST tag N-Terminus


Our Abpromise guarantee covers the use of ab56280 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

  • Applications

    Functional Studies


    Western blot

  • Purity
    > 90 % SDS-PAGE.

  • Form
  • Concentration information loading...

Preparation and Storage

  • Stability and Storage

    Shipped on dry ice. Upon delivery aliquot and store at -80ºC. Avoid freeze / thaw cycles.

    pH: 7.50
    Constituents: 0.0038% EGTA, 0.00174% PMSF, 0.00385% DTT, 0.79% Tris HCl, 0.00292% EDTA, 25% Glycerol, 0.87% Sodium chloride

General Info

  • Alternative names
    • Activator protein 1
    • AP 1
    • C FOS
    • Cellular oncogene c fos
    • Cellular oncogene fos
    • FBJ murine osteosarcoma viral (v fos) oncogene homolog (oncogene FOS)
    • FBJ murine osteosarcoma viral oncogene homolog
    • FBJ murine osteosarcoma viral v fos oncogene homolog
    • FBJ Osteosarcoma Virus
    • FOS
    • FOS protein
    • G0 G1 switch regulatory protein 7
    • G0/G1 switch regulatory protein 7
    • G0S7
    • Oncogene FOS
    • p55
    • proto oncogene c Fos
    • Proto oncogene protein c fos
    • Proto-oncogene c-Fos
    • v fos FBJ murine osteosarcoma viral oncogene homolog
    see all
  • Function
    Nuclear phosphoprotein which forms a tight but non-covalently linked complex with the JUN/AP-1 transcription factor. In the heterodimer, FOS and JUN/AP-1 basic regions each seems to interact with symmetrical DNA half sites. On TGF-beta activation, forms a multimeric SMAD3/SMAD4/JUN/FOS complex at the AP1/SMAD-binding site to regulate TGF-beta-mediated signaling. Has a critical function in regulating the Has a critical function in regulating the development of cells destined to form and maintain the skeleton. It is thought to have an important role in signal transduction, cell proliferation and differentiation.
  • Sequence similarities
    Belongs to the bZIP family. Fos subfamily.
    Contains 1 bZIP domain.
  • Post-translational
    Phosphorylated in the C-terminal upon stimulation by nerve growth factor (NGF) and epidermal growth factor (EGF). Phosphorylated, in vitro, by MAPK and RSK1. Phosphorylation on both Ser-362 and Ser-374 by MAPK1/2 and RSK1/2 leads to protein stabilization with phosphorylation on Ser-374 being the major site for protein stabilization on NGF stimulation. Phosphorylation on Ser-362 and Ser-374 primes further phosphorylations on Thr-325 and Thr-331 through promoting docking of MAPK to the DEF domain. Phosphorylation on Thr-232, induced by HA-RAS, activates the transcriptional activity and antagonizes sumoylation. Phosphorylation on Ser-362 by RSK2 in osteoblasts contributes to osteoblast transformation.
    Constitutively sumoylated by SUMO1, SUMO2 and SUMO3. Desumoylated by SENP2. Sumoylation requires heterodimerization with JUN and is enhanced by mitogen stimulation. Sumoylation inhibits the AP-1 transcriptional activity and is, itself, inhibited by Ras-activated phosphorylation on Thr-232.
  • Cellular localization
  • Information by UniProt


  • SDS-PAGE analysis of ab56280 with molecular weight markers. Approximate molecular weight 78kDa due to presence of a Tag.

  • Anti-c-Fos antibody - ChIP Grade (ab7963) at 1 µg/ml + Recombinant Human c-Fos protein (ab56280) at 0.1 µg

    Goat Anti-Rabbit IgG H&L (HRP) preadsorbed (ab97080) at 1/5000 dilution

    Developed using the ECL technique.

    Performed under reducing conditions.

    Additional bands at: 75 kDa (possible tagged protein)

    Exposure time: 20 seconds


ab56280 has not yet been referenced specifically in any publications.

Customer reviews and Q&As

1-2 of 2 Q&A


Thank you for contacting us.

We produce c-FOS in insect cells, so the protein may have some phosphorylation levels in some sites. We’ve tried to limit the kinase activity during the production process, including the expression stages and purification steps, but we can’t protect its phosphorylation completely. Also, we can’t test the modification levels in all of the sites, but we still think our c-FOS protein is a good substrate for most of application assays. Even you had the positive signal in the Thr232, we don’t think that site has been fully phosphorylated, and you may have used too much protein (˜80ng) to do the WB.

We would suggest that you do a dilution study (such as starts at 20ng>>>) in WB with phosphor-antibody and protein-antibody, and to see if you can get the protein amount point which shows the positive signal in protein-Ab and negative one in phosphor-Ab. You may then use the optimized protein amount to do his test

I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.

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Thank you for your enquiry. The MW weight of the GST tag is approximately 25kDa. The FOS protein is about 53kDa. Therefore, as seen on the WB image, a 78kDa band was detected.

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