HSF1 Human

Heat Shock Transcription Factor-1 (HSF1) is a highly conserved transcription factor found in eukaryotes. It plays a crucial role in the cellular response to stress, particularly heat shock, by regulating the expression of heat shock proteins (HSPs). These proteins function as molecular chaperones, aiding in the refolding of misfolded proteins and the degradation of damaged proteins. HSF1 is not only essential for stress response but also involved in various physiological processes, including development, metabolism, and aging .

HSF1 is characterized by an N-terminal helix-turn-helix DNA-binding domain and an adjacent oligomerization domain consisting of hydrophobic heptad repeats (HR-A/B). In unstressed cells, HSF1 exists in an inactive monomeric form. Upon exposure to stress, HSF1 undergoes trimerization and phosphorylation, which activates its DNA-binding ability. The activated HSF1 trimer translocates to the nucleus, where it binds to heat shock-responsive DNA elements (HSEs) to initiate the transcription of HSP genes .

The primary function of HSF1 is to mediate the transcriptional response to proteotoxic stress. When cells are exposed to elevated temperatures or other stressors, HSF1 rapidly induces the expression of HSPs. These proteins help maintain protein homeostasis (proteostasis) by preventing the aggregation of misfolded proteins and facilitating their refolding or degradation. This response is critical for cell survival under stress conditions .

Recent studies have revealed that HSF1 also plays significant roles in non-stress conditions. It is involved in various physiological processes, including metabolism, gametogenesis, and aging. HSF1’s ability to reprogram transcription extends beyond the heat shock response, influencing a wide range of cellular functions. For instance, HSF1 has been implicated in cancer progression, where it supports the survival and proliferation of cancer cells by regulating the expression of genes involved in cell growth and survival .

Recombinant HSF1 refers to the HSF1 protein that has been produced using recombinant DNA technology. This involves inserting the HSF1 gene into a suitable expression system, such as bacteria or yeast, to produce the protein in large quantities. Recombinant HSF1 is used in various research applications to study its structure, function, and role in cellular processes. It is also employed in drug discovery efforts aimed at targeting HSF1 for therapeutic purposes, particularly in diseases where HSF1 activity is dysregulated .