• Product name
  • Description
    Rabbit polyclonal to HSF1
  • Host species
  • Tested applications
    Suitable for: EMSA, IP, WB, ELISA, ICC/IF, Inhibition Assaymore details
  • Species reactivity
    Reacts with: Mouse, Rat, Human
  • Immunogen

    Other Immunogen Type corresponding to Human HSF1. Recombinant human HSF1 expressed in E. coli.

  • Positive control
    • 3T3 cell lysate.


  • Form
  • Storage instructions
    Shipped at 4°C. Store at +4°C short term (1-2 weeks). Upon delivery aliquot. Store at -20°C. Avoid freeze / thaw cycle.
  • Storage buffer
    Preservative: 0.05% Sodium azide
    Constituent: 99% PBS
  • Purity
    Whole antiserum
  • Primary antibody notes
    All organisms respond to elevated temperatures and a variety of environmental stresses by rapid synthesis of heat shock RNAs and proteins. The regulation of heat shock gene transcription is mediated by the transcriptional activator, heat shock factor (HSF), which binds to heat shock response elements (HSEs). These HSEs are found as three repeats of a 5-nucleotide {nGAAn} module, arranged in alternating orientation and present upstream of all heat shock genes. The HSEs are highly conserved among species yet HSF purified from yeast, Drosophila and human have different molecular weights and the proteins do not show significant immunological cross reaction. Two HSFs have been identified in human cells, HSF 1 and HSF 2, which bind to the same HSEs and have 38% sequence identity. These factors are activated by distinct stimuli, HSF 1 is responsive to classical stress signals such as heat, heavy metals and oxidative reagents, whereas HSF 2 is activated during hemin-mediated differentiation of human erythroleukemia cells. HSF 1 exists constitutively in the cytoplasm and the nucleus of unstressed cells as a monomer which lacks DNA binding activity. Through an unknown signal generated during stress, HSF 1 becomes activated to a nuclear localized, trimeric state which binds to DNA. The phosphorylation of HSF 1 is necessary for maximal transcription of heat shock genes.
  • Clonality
  • Isotype
  • Research areas


Our Abpromise guarantee covers the use of ab2923 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
EMSA Use at an assay dependent concentration. PubMed: 18429957
EMSA Use at an assay dependent concentration.
IP Use at an assay dependent concentration.

2 μg

WB 1/1000 - 1/10000. Detects a band of approximately 83 kDa (predicted molecular weight: 57 kDa).
ELISA Use at an assay dependent concentration.
ICC/IF 1/50.
Inhibition Assay 1/1000.


  • Function
    DNA-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 similarities
    Belongs to the HSF family.
  • Domain
    the 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 localization
    Cytoplasm. 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


  • Immunocytochemistry/Immunofluorescence analysis of HSF1 (green) in HeLa and NIH3T3 cells. Formalin fixed cells were permeabilized with 0.1% Triton X-100 in TBS for 10 minutes at room temperature and blocked with 1% BSA for 15 minutes at room temperature. Cells were probed with ab2923 (1:50) for at least 1 hour at room temperature, washed with PBS, and incubated with a DyLight 488-conjugated goat-anti rabbit IgG secondary antibody (1:400) for 30 minutes at room temperature. Nuclei (blue) were stained with Hoechst 33342 dye. Images were taken at 20X magnification.

  • Immunoprecipitation of HSF1 was performed on HeLa cells. Antigen:antibody complexes were formed by incubating 500µg whole cell lysate with 2µg of ab2923 overnight on a rocking platform at 4°C. Immune complexes were captured on 50µl Protein A/G Plus Agarose, washed extensively, and eluted with buffer. Samples were resolved on a 4-20% Tris-HCl polyacrylamide gel, transferred to a PVDF membrane, and blocked with 5% BSA/TBST for at least 1 hour. The membrane was incubated with ab2923 (1:1000) overnight rotating at 4°C, washed in TBST, and probed with detection reagent (1:1000) for at least one hour. Chemiluminescent detection was performed.

  • Western blot analysis of Heat Shock Factor 1 (HSF1) was performed by loading 50µg of the indicated whole cell lysates per well onto a 4-20% Tris-HCl polyacrylamide gel. Proteins were transferred to a PVDF membrane and blocked with 5% BSA/TBST for at least 1 hour. The membrane was incubated with ab2923 (1/1000) overnight at 4°C on a rocking platform, washed in TBS-0.1% Tween 20, and probed with a HRP-conjugated goat anti-rabbit IgG secondary antibody (1/20,000) for at least one hour. Chemiluminescent detection was performed.


This product has been referenced in:
  • Neueder A  et al. Novel Isoforms of Heat Shock Transcription Factor 1, HSF1?a and HSF1?ß, Regulate Chaperone Protein Gene Transcription. J Biol Chem 289:19894-906 (2014). Read more (PubMed: 24855652) »
  • Zhang L  et al. Hsp70 inhibition induces myeloma cell death via the intracellular accumulation of immunoglobulin and the generation of proteotoxic stress. Cancer Lett 339:49-59 (2013). WB ; Human . Read more (PubMed: 23887058) »

See all 9 Publications for this product

Customer reviews and Q&As

Thank you for contacting us regaridng testing of these product in C.elegans. I have created two codes for you. Please be aware that each code is linked to a specific antibody. I am very pleased to hear you would like to accept our offer and test the...

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Thank you for contacting Abcam. I have processed a free of charge replacement for ab2923. If there is anything else I can help with, please let me know.

The cells were heat shocked at ~44 degrees celcius at different time points from 0-6 hours. We unfortunately don't have anymore exact information. If you have any additional questions, please contact us again.

Thank you for your enquiry. I am sorry to hear that you are having problems with your anti-HSF1 (ab2923) antibody. Following on from your on line submission. It seems that you are obtaining good quality results with your GST-HSF1 fusion positiv...

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Thank you for your enquiry regarding ab2923. I am sorry to hear that you have had problems with this antibody. You have done alot of work to optimize it and your procedure looks very good. I can send you a replacement vial of a different lot numbe...

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