Dimerization of Hsp90 is required for in vivo function. Design and analysis of monomers and dimers

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology

Publication Date


Document Type



Adenosine Triphosphatases; Adenosine Triphosphate; Circular Dichroism; Dimerization; Fluorescent Dyes; HSP90 Heat-Shock Proteins; Humans; Hydrolysis; Models, Molecular; Protein Binding; Protein Engineering; Protein Structure, Tertiary; Proteins; Saccharomyces cerevisiae; Substrate Specificity


Life Sciences | Medicine and Health Sciences


Heat shock protein 90 (Hsp90) plays a central role in signal transduction and has emerged as a promising target for anti-cancer therapeutics, but its molecular mechanism is poorly understood. At physiological concentration, Hsp90 predominantly forms dimers, but the function of full-length monomers in cells is not clear. Hsp90 contains three domains: the N-terminal and middle domains contribute directly to ATP binding and hydrolysis and the C domain mediates dimerization. To study the function of Hsp90 monomers, we used a single-chain strategy that duplicated the C-terminal dimerization domain. This novel monomerization strategy had the dual effect of stabilizing the C domain to denaturation and hindering intermolecular association of the ATPase domain. The resulting construct was predominantly monomeric at physiological concentration and did not function to support yeast viability as the sole Hsp90. The monomeric construct was also defective at ATP hydrolysis and the activation of a kinase and steroid receptor substrate in yeast cells. The ability to support yeast growth was rescued by the addition of a coiled-coil dimerization domain, indicating that the parental single-chain construct is functionally defective because it is monomeric.

DOI of Published Version



J Biol Chem. 2007 Nov 30;282(48):35386-95. Epub 2007 Oct 1. Link to article on publisher's site

Journal/Book/Conference Title

The Journal of biological chemistry

Related Resources

Link to Article in PubMed

PubMed ID