Intermolecular Interactions between Hsp90 and Hsp70

Publication date: Available online 22 May 2019Source: Journal of Molecular BiologyAuthor(s): Shannon M. Doyle, Joel R. Hoskins, Andrea N. Kravats, Audrey L. Heffner, Srilakshmi Garikapati, Sue WicknerAbstractMembers of the Hsp90 and Hsp70 families of molecular chaperones are important for the maintenance of protein homeostasis and cellular recovery following environmental stresses, such as heat and oxidative stress. Moreover, the two chaperones can collaborate in protein remodeling and activation. In higher eukaryotes, Hsp90 and Hsp70 form a functionally active complex with Hop (Hsp90-Hsp70 organizing protein) acting as a bridge between the two chaperones. In bacteria, which do not contain a Hop homolog, Hsp90 and Hsp70, DnaK, directly interact during protein remodeling. Although yeast possess a Hop-like protein, Sti1, Hsp90 and Hsp70 can directly interact in yeast in the absence of Sti1. Previous studies showed that residues in the middle domain of Escherichia coli Hsp90 are important for interaction with the J-protein binding region of DnaK. The results did not distinguish between the possibility that i) these sites were involved in direct interaction and ii) the residues in these sites participate in conformational changes which are transduced to other sites on Hsp90 and DnaK that are involved in the direct interaction. Here we show by crosslinking experiments that the direct interaction is between a site in the middle domain of Hsp90 and the J-protein binding site of Hsp7...
Source: Journal of Molecular Biology - Category: Molecular Biology Source Type: research