Functional analysis of the gene controlling hydroxylation of festuclavine in the ergot alkaloid pathway of Neosartorya fumigata
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- 作者：Yulia Bilovol ; Daniel G. Panaccione
- 关键词：Mycotoxin ; Clavines ; P450 monooxygenase ; Gene cluster ; Aspergillus fumigatus
- 刊名：Current Genetics
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：62
- 期：4
- 页码：853-860
- 全文大小：727 KB
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Life Sciences
Microbial Genetics and Genomics
Microbiology
Biochemistry
Cell Biology
Plant Sciences
Proteomics - 出版者：Springer Berlin / Heidelberg
- ISSN：1432-0983
- 卷排序：62
文摘
Bioactive ergot alkaloids produced by several species of fungi are important molecules in agriculture and medicine. Much of the ergot alkaloid pathway has been elucidated, but a few steps, including the gene controlling hydroxylation of festuclavine to fumigaclavine B, remain unsolved. Festuclavine is a key intermediate in the fumigaclavine branch of the ergot alkaloid pathway of the opportunistic pathogen Neosartorya fumigata and also in the dihydrolysergic acid-based ergot alkaloid pathway of certain Claviceps species. Based on several lines of evidence, the N. fumigata gene easM is a logical candidate to encode the festuclavine-hydroxylating enzyme. To test this hypothesis we disrupted easM function by replacing part of its coding sequences with a hygromycin resistance gene and transforming N. fumigata with this construct. High-pressure liquid chromatography analysis demonstrated that easM deletion mutants were blocked in the ergot alkaloid pathway at festuclavine, and downstream products were eliminated. An additional alkaloid, proposed to be a prenylated form of festuclavine on the basis of mass spectral data, also accumulated to higher concentrations in the easM knockout. Complementation with the wild-type allele of easM gene restored the ability of the fungus to produce downstream compounds. These results indicate that easM encodes an enzyme required for fumigaclavine B synthesis likely by hydroxylating festuclavine. The festuclavine-accumulating strain of N. fumigata may facilitate future investigations of the biosynthesis of dihydrolysergic acid derivatives, which are derived from festuclavine and are the basis for several important drugs.