HSF1 Monoclonal Antibody (4B4), PerCP, Invitrogen™

Description

• 1 μg/mL of MA5-45714 was sufficient for detection of HSF1 in 20 μg of heat shocked HeLa cell lysate by colorimetric immunoblot analysis using Rabbit anti-rat IgG: AP as the secondary antibody.∣Detects approximately 85kDa (unstressed cell lysates) and approximately 95kDa (heat shocked cell lysates)
• 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, HSF1 and HSF2, which bind to the same HSEs and have 38% sequence identity
• These factors are activated by distinct stimuli, HSF1 is responsive to classical stress signals such as heat, heavy metals and oxidative reagents, whereas HSF2 is activated during hemin-mediated differentiation of human erythroleukemia cells
• HSF1 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, HSF1 becomes activated to a nuclear localized, trimeric state which binds to DNA
• The phosphorylation of HSF1 is necessary for maximal transcription of heat shock genes.