Tenellin acts as an iron chelator to prevent iron-generated reactive oxygen species toxicity in the entomopathogenic fungus Beauveria bassiana.

Jiraporn Jirakkakul, Supapon Cheevadhanarak, Juntira Punya, Chanikul Chutrakul, Jittisak Senachak, Taridaporn Buajarern, Morakot Tanticharoen, Alongkorn Amnuaykanjanasin

Index: FEMS Microbiol. Lett. 362 , 1-8, (2015)

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Abstract

Iron is an essential element for life. However, the iron overload can be toxic. Here, we investigated the significant increase of tenellin and iron-tenellin complex production in ferricrocin-deficient mutants of Beauveria bassiana. Our chemical analysis indicated that the ferricrocin-deficient mutants T1, T3 and T5 nearly abolished ferricrocin production. In turn, these mutants had significant accumulation of iron-tenellin complex in their mycelia at 247-289 mg g(-1) cell dry weight under iron-replete condition. Both tenellin and iron-tenellin complex were not detected in the wild-type under such condition. Mass analysis of the mutants' crude extracts demonstrated that tenellin formed a 3:1 complex with iron in the absence of ferricrocin. The unexpected link between ferricrocin and tenellin biosynthesis in ferricrocin-deficient mutants could be a survival strategy during iron-mediated oxidative stress. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.