Diptoindonesin G, a new Hsp90 drug

Hsp90 is a molecular chaperone that participates in protein folding, activation, and stabilization of substrate proteins. Since many diseases, including cancer, neurodegenerative dis-eases, and metabolic diseases, are caused by protein misfolding, drugs that inhibit Hsp90 are being pursued as potential targets for treatments. In the recent JBC Editor's Pick by Donahue et al., the authors show that diptoindonesin G is a new Hsp90 inhibitor that promotes degradation of the estrogen receptor, an Hsp90 client, without inducing the heat shock response.