Hsp100

Hsp100 refers to a family of molecular chaperones found in all domains of life. These proteins are a subgroup of the heat shock proteins (HSPs) and play a crucial role in cellular protein homeostasis. Hsp100s are characterized by their AAA+ (ATPases Associated with diverse cellular Activities) domain, which is essential for their function. They typically exist as hexameric ring-like structures that utilize the energy from ATP hydrolysis to refold misfolded proteins, disaggregate protein aggregates, or assist in the degradation of damaged proteins.

The precise mechanisms by which Hsp100s operate are complex and often involve interaction with other chaperone proteins, such as Hsp70 and Hsp40. In bacteria, the Hsp100 homolog ClpB works in conjunction with Hsp70 to solubilize protein aggregates. In eukaryotes, Hsp100s are involved in various cellular processes including protein translocation across membranes, DNA repair, and stress response. For example, the human Hsp104 homolog is involved in disaggregating damaged proteins, which is critical for cellular survival under stress conditions. Mutations or dysregulation of Hsp100 activity have been linked to various diseases, including neurodegenerative disorders, highlighting their importance in maintaining cellular health.