10.3389/fphar.2019.01160.s001 Juan Antonio Torres Acosta Juan Antonio Torres Acosta Herbert Michlmayr Herbert Michlmayr Mehrdad Shams Mehrdad Shams Wolfgang Schweiger Wolfgang Schweiger Gerlinde Wiesenberger Gerlinde Wiesenberger Rudolf Mitterbauer Rudolf Mitterbauer Ulrike Werner Ulrike Werner David Merz David Merz Marie-Theres Hauser Marie-Theres Hauser Christian Hametner Christian Hametner Elisabeth Varga Elisabeth Varga Rudolf Krska Rudolf Krska Franz Berthiller Franz Berthiller Gerhard Adam Gerhard Adam DataSheet_1_Zearalenone and ß-Zearalenol But Not Their Glucosides Inhibit Heat Shock Protein 90 ATPase Activity.pdf Frontiers 2019 Arabidopsis HSP90 wheat glycosylation Fusarium radicicol 2019-10-18 13:53:45 Dataset https://frontiersin.figshare.com/articles/dataset/DataSheet_1_Zearalenone_and_-Zearalenol_But_Not_Their_Glucosides_Inhibit_Heat_Shock_Protein_90_ATPase_Activity_pdf/10002938 <p>The mycotoxin zearalenone (ZEN) is produced by many plant pathogenic Fusarium species. It is well known for its estrogenic activity in humans and animals, but whether ZEN has a role in plant–pathogen interaction and which process it is targeting in planta was so far unclear. We found that treatment of Arabidopsis thaliana seedlings with ZEN induced transcription of the AtHSP90.1 gene. This heat shock protein (HSP) plays an important role in plant–pathogen interaction, assisting in stability and functionality of various disease resistance gene products. Inhibition of HSP90 ATPase activity impairs functionality. Because HSP90 inhibitors are known to induce HSP90 gene expression and due to the structural similarity with the known HSP90 inhibitor radicicol (RAD), we tested whether ZEN and its phase I metabolites α- and ß-zearalenol are also HSP90 ATPase inhibitors. Indeed, AtHSP90.1 and wheat TaHSP90-2 were inhibited by ZEN and ß-zearalenol, while α-zearalenol was almost inactive. Plants can efficiently glycosylate ZEN and α/ß-zearalenol. We therefore tested whether glucosylation has an effect on the inhibitory activity of these metabolites. Expression of the A. thaliana glucosyltransferase UGT73C6 conferred RAD resistance to a sensitive yeast strain. Glucosylation of RAD, ZEN, and α/ß-zearalenol abolished the in vitro inhibitory activity with recombinant HSP90 purified from Escherichia coli. In conclusion, the mycotoxin ZEN has a very prominent target in plants, HSP90, but it can be inactivated by glycosylation. This may explain why there is little evidence for a virulence function of ZEN in host plants.</p>