PMID: 25785725

Authors:

Lee C, Park HK, Jeong H, Lim J, Lee AJ, Cheon KY, Kim CS, Thomas AP, Bae B, Kim ND, Kim SH, Suh PG, Ryu JH, Kang BH

Title:

Development of a Mitochondria-Targeted Hsp90 Inhibitor Based on the Crystal Structures of Human TRAP1.

Journal:

J Am Chem Soc. 2015 Apr 8;137(13):4358-67. doi: 10.1021/ja511893n. Epub 2015 Mar , 30.

Abstract:

The mitochondrial pool of Hsp90 and its mitochondrial paralogue, TRAP1, suppresses cell death and reprograms energy metabolism in cancer cells; therefore, Hsp90 and TRAP1 have been suggested as target proteins for anticancer drug development. Here, we report that the actual target protein in cancer cell mitochondria is TRAP1, and current Hsp90 inhibitors cannot effectively inactivate TRAP1 because of their insufficient accumulation in the mitochondria. To develop mitochondrial TRAP1 inhibitors, we determined the crystal structures of human TRAP1 complexed with Hsp90 inhibitors. The isopropyl amine of the Hsp90 inhibitor PU-H71 was replaced with the mitochondria-targeting moiety triphenylphosphonium to produce SMTIN-P01. SMTIN-P01 showed a different mode of action from the nontargeted PU-H71, as well as much improved cytotoxicity to cancer cells. In addition, we determined the structure of a TRAP1-adenylyl-imidodiphosphate (AMP-PNP) complex. On the basis of comparative analysis of TRAP1 structures, we propose a molecular mechanism of ATP hydrolysis that is crucial for chaperone function.