AUTHOR=Liu Jiao , Lei Ming , Zhou Youxiang , Chen Fusheng 

TITLE=A Comprehensive Analysis of the Small GTPases Ypt7 Involved in the Regulation of Fungal Development and Secondary Metabolism in Monascus ruber M7

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.00452

DOI=10.3389/fmicb.2019.00452

ISSN=1664-302X

ABSTRACT=<p>Ypts (<italic>y</italic>east <italic>p</italic>rotein <italic>t</italic>ransport<italic>s</italic>),also called as <italic>r</italic>as-<italic>a</italic>ssociated <italic>b</italic>inding GTPases (Rab), are the largest group of the small GTPases family, which have been extensively studied in model eukaryotic cells and play a pivotal role in membane trafficking, while this study showed potential regulation role of Ypts in fungi. One of Ypts, Ypt7 may be involved in fungal development and secondary metabolism, but the exact mechanism still exists a controversy. In current study, the functions of a <italic>Monascus ypt7</italic> homologous gene (<italic>mrypt</italic>7) from <italic>Monascus ruber</italic> M7 was investigated by combination of gene-deletion (Δ<italic>mrypt</italic>7), overexpression (M7::<italic>PtrpC</italic>-<italic>mrypt</italic>7) and transcriptome analysis. Results showed that the radial growth rate of Δ<italic>mrypt</italic>7 was significantly slower than <italic>M. ruber</italic> M7, little conidia and ascospores can be observed in Δ<italic>mrypt</italic>7, but the yield of intracellular secondary metabolites was dramatically increased. Simultaneously, the <italic>mrypt</italic>7 overexpression strain possessed similar capacity for sporulation and secondary metabolism observed in <italic>M. ruber</italic> M7. Transcriptome results further illustrated that <italic>mrypt</italic>7 could coordinate with numerous genes involved in the vegetative growth, conidiogenesis, secondary metabolism biosynthesis and transportation of <italic>M. ruber</italic> M7. Combined with the similar effect of Ypt7 homologs on other fungi, we propose that Ypt7 works more like a global regulatory factor in fungi. To our knowledge, it is the first time to investigate Ypt7 functions in <italic>Monascus</italic>. It could also improve the understanding of Ypt7 functions in fungi.</p>