HSF1 (phosphorylated) (human), (recombinant) (His-tag)

In response to adverse changes in their environment, cells from many organisms increase the expression of a class of proteins referred to as heat shock or stress proteins. The expression of heat shock proteins is mediated by the binding of a heat shock transcriptional factor (HSF) to a heat shock response element (HSE) which is located upstream of heat shock protein genes. Two heat shock transcriptional factors, termed HSF1 and HSF2, have been identified in mice and humans. In unstressed cells, HSF1 is a non-DNA binding monomeric protein present in the cytosol and nuclear compartments. However, in response to heat and heavy metals, HSF1 rapidly converts to a transcriptionally active form – a process requiring oligomerization to a trimer, serine phosphorylation, and translocation to the nucleus. HSF2, on the other hand, is not activated by heat, but is involved in regulating heat shock gene transcription during cell differentiation and development.