GSE140563 Investigating the mechanism by which the natural product compound puupehenone potentiates the antifungal drug caspofungin

In this study, we show that puupehenone (PUUP), a marine sponge-derived sesquiterpene quinone potentiates the echinocandin drug, caspofungin (CAS) in CAS-resistant fungal pathogens. We have conducted RNA-Seq analysis, followed by genetic and molecular studies, to elucidate PUUP ’s CAS-potentiating mechanism. We found that the combination of CAS and PUUP blocked the induction of CAS-responding genes required for the adaptation to cell wall stress through the cell wall integrity (CWI) pathway. Further analysis showed that PUUP inhibited the activation of Slt2 (Mpk1), the t erminal MAP kinase in this pathway. We also found that PUUP induced heat shock response genes and inhibited the activity of heat shock protein 90 (Hsp90). Molecular docking studies predicted that PUUP occupies a binding site on Hsp90 required for the interaction between Hsp90 and its co-chaperone Cd c37. Thus, we show that PUUP potentiates CAS activity by a previously undescribed mechanism which involves disruption of Hsp90 activity and the CWI pathway. Given the requirement of the Hsp90-Cdc37 complex in Slt2 activation, we suggest that inhibitors of this complex would disrupt the CWI pathway a nd synergize with echinocandins. Therefore, the identification of PUUP’s CAS-potentiating mechanism has important implications in the development of new antifungal combination therapies.
Source: GEO: Gene Expression Omnibus - Category: Genetics & Stem Cells Tags: Expression profiling by high throughput sequencing Saccharomyces cerevisiae Source Type: research