کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2580663 1561635 2013 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Steroid toxicity and detoxification in ascomycetous fungi
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست بهداشت، سم شناسی و جهش زایی
پیش نمایش صفحه اول مقاله
Steroid toxicity and detoxification in ascomycetous fungi
چکیده انگلیسی

In the last couple of decades fungal infections have become a significant clinical problem. A major interest into fungal steroid action has been provoked since research has proven that steroid hormones are toxic to fungi and affect the host/fungus relationship. Steroid hormones were found to differ in their antifungal activity in ascomycetous fungi Hortaea werneckii, Saccharomyces cerevisiae and Aspergillus oryzae. Dehydroepiandrosterone was shown to be the strongest inhibitor of growth in all three varieties of fungi followed by androstenedione and testosterone. For their protection, fungi use several mechanisms to lower the toxic effects of steroids. The efficiency of biotransformation in detoxification depended on the microorganism and steroid substrate used. Biotransformation was a relatively slow process as it also depended on the growth phase of the fungus. In addition to biotransformation, steroid extrusion out of the cells contributed to the lowering of the active intracellular steroid concentration. Plasma membrane Pdr5 transporter was found to be the most effective, followed by Snq2 transporter and vacuolar transporters Ybt1 and Ycf1. Proteins Aus1 and Dan1 were not found to be involved in steroid import. The research of possible targets of steroid hormone action in fungi suggests that steroid hormones inhibit ergosterol biosynthesis in S. cerevisiae and H. werneckii. Results of this inhibition caused changes in the sterol content of the cellular membrane. The presence of steroid hormones most probably causes the degradation of the Tat2 permease and impairment of tryptophan import.


► Dehydroepiandrosterone was found to be the most toxic steroid to ascomycetous fungi.
► Fungi use several mechanisms of protection against toxic steroids.
► Steroid hormones inhibit ergosterol biosynthesis in Saccharomyces cerevisiae and Hortaea werneckii.
► This inhibition might result in impaired tryptophan uptake observed in S. cerevisiae.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemico-Biological Interactions - Volume 202, Issues 1–3, 25 February 2013, Pages 243–258
نویسندگان
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