Anti-HSF1 (phospho S303 + S307) antibody [EP1711Y] (ab81281)


  • Product nameAnti-HSF1 (phospho S303 + S307) antibody [EP1711Y]
    See all HSF1 primary antibodies
  • Description
    Rabbit monoclonal [EP1711Y] to HSF1 (phospho S303 + S307)
  • Specificityab81281 antibody recognises HSF1 (phospho S303 + S307)
  • Tested applicationsSuitable for: WB, IHC-P, ICC/IFmore details
    Unsuitable for: Flow Cyt or IP
  • Species reactivity
    Reacts with: Human
  • Immunogen

    Synthetic peptide (the amino acid sequence is considered to be commercially sensitive)

  • Positive control
    • HeLa cell lysates, Human breast carcinoma.
  • General notes

    Produced using Abcam’s RabMAb® technology. RabMAb® technology is covered by the following U.S. Patents, No. 5,675,063 and/or 7,429,487.

    Mouse, Rat: We have preliminary internal testing data to indicate this antibody may not react with these species. Please contact us for more information.



Our Abpromise guarantee covers the use of ab81281 in the following tested applications.

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

Application Abreviews Notes
WB 1/5000 - 1/50000. Predicted molecular weight: 57 kDa.
IHC-P 1/100 - 1/250. Perform heat mediated antigen retrieval before commencing with IHC staining protocol.
ICC/IF 1/250 - 1/500.
  • Application notesIs unsuitable for Flow Cyt or IP.
  • Target

    • FunctionDNA-binding protein that specifically binds heat shock promoter elements (HSE) and activates transcription. In higher eukaryotes, HSF is unable to bind to the HSE unless the cells are heat shocked.
    • Sequence similaritiesBelongs to the HSF family.
    • Domainthe 9aaTAD motif is a transactivation domain present in a large number of yeast and animal transcription factors.
    • Post-translational
      Phosphorylated on multiple serine residues, a subset of which are involved in stress-related regulation of transcription activation. Constitutive phosphorylation represses transcriptional activity at normal temperatures. Levels increase on specific residues heat-shock and enhance HSF1 transactivation activity. Phosphorylation on Ser-307 derepresses activation on heat-stress and in combination with Ser-303 phosphorylation appears to be involved in recovery after heat-stress. Phosphorylated on Ser-230 by CAMK2, in vitro. Cadmium also enhances phosphorylation at this site. Phosphorylation on Ser-303 is a prerequisite for HSF1 sumoylation. Phosphorylation on Ser-121 inhibits transactivation and promotes HSP90 binding. Phosphorylation on Thr-142 also mediates transcriptional activity induced by heat. Phosphorylation on Ser-326 plays an important role in heat activation of HSF1 transcriptional activity.
      Sumoylated with SUMO1 and SUMO2 on heat-shock. Heat-inducible sumoylation occurs after 15 min of heat-shock, after which levels decrease and at 4 hours, levels return to control levels. Sumoylation has no effect on HSE binding nor on transcriptional activity. Phosphorylation on Ser-303 is a prerequisite for sumoylation.
    • Cellular localizationCytoplasm. Nucleus. Cytoplasmic during normal growth. On activation, translocates to nuclear stress granules. Colocalizes with SUMO1 in nuclear stress granules.
    • Information by UniProt
    • Database links
    • Alternative names
      • Heat shock factor 1 antibody
      • Heat shock factor protein 1 antibody
      • Heat shock transcription factor 1 antibody
      • HSF 1 antibody
      • hsf1 antibody
      • HSF1_HUMAN antibody
      • HSTF 1 antibody
      • HSTF1 antibody
      see all

    Anti-HSF1 (phospho S303 + S307) antibody [EP1711Y] images

    • All lanes : Anti-HSF1 (phospho S303 + S307) antibody [EP1711Y] (ab81281) at 1/50000 dilution

      Lane 1 : HeLa cell lysate untreated
      Lane 2 : HeLa cell lysate AP treated

      Lysates/proteins at 10 µg per lane.

      HRp labelled goat anti rabbit at 1/2000 dilution

      Predicted band size : 57 kDa
      Observed band size : 80 kDa (why is the actual band size different from the predicted?)
    • Immunohistochemical analysis of paraffin-embedded human breast carcinoma using 1/100 ab81281

    References for Anti-HSF1 (phospho S303 + S307) antibody [EP1711Y] (ab81281)

    This product has been referenced in:
    • Zhao J  et al. Correlation between the expression of Id-1 and hyperthermia-associated molecules in oral squamous cell carcinoma. J Clin Pathol 66:758-63 (2013). IHC ; Human . Read more (PubMed: 23723304) »

    See 1 Publication for this product

    Product Wall

    Thank you for contacting us and bringing this to our attention.

    We have tested both products (ab76076 and ab81281) in mouse and rat samples, via WB.
    The samples we tested were brain, heart, kidney and spleen for each, in mouse and r...

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