Heat Shock Factor 1 (Heat Shock Transcription Factor 1, HSF1, HSTF1)

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.\n\nApplications: \nSuitable for use in GS, Western Blot and Immunoprecipitation. Other applications not tested.\n\nRecommended Dilution:\nOptimal dilutions to be determined by the researcher.\n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. For long-term storage and to avoid repeated freezing and thawing, aliquot Store at -20 degrees C. Aliquots are stable for at least 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

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SPECIFICATIONS

Catalog Number

H1830-44B

Size

100ul

Applications

IP, WB

Hosts

Rabbit

Reactivities

Hum, Mouse, Rat

Form

Supplied as a liquid in PBS, pH 7.2, 0.05% sodium azide.

P Type

Pab

Purity

Whole antisera

Isotype

IgG

References

This product has been used in:Sun L et al. Activation of HSF and selective increase in heat-shock proteins by acute dexamethasone treatment. Am J Physiol Heart Circ Physiol 278:H1091-7 (2000). <PUBMED:10749702> Human heat shock factors 1 and 2 are differentially activated and can synergistically induce hsp70 gene transcription. Mol Cell Biol 14:2087-99 (1994). <PUBMED:8114740>Jurivich DA et al. Arachidonate is a potent modulator of human heat shock gene transcription. Proc Natl Acad Sci U S A 91:2280-4 (1994). <PUBMED:8134388>Rabindran SK et al. Regulation of heat shock factor trimer formation: role of a conserved leucine zipper. Science 259:230-4 (1993). <PUBMED:8421783>Sorger PK Heat shock factor and the heat shock response. Cell 65:363-6 (1991). <PUBMED:2018972>Rabindran SK et al. Molecular cloning and expression of a human heat shock factor, HSF1. Proc Natl Acad Sci U S A 88:6906-10 (1991). <PUBMED:1871105>

Additional Info

Species Crossreactivity: Crossreacts with Human, Rat and Mouse.