Abstract
Ypts (yeast protein transports),also called as ras-associated binding 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 Monascus ypt7 homologous gene (mrypt7) from Monascus ruber M7 was investigated by combination of gene-deletion (Δmrypt7), overexpression (M7::PtrpC-mrypt7) and transcriptome analysis. Results showed that the radial growth rate of Δmrypt7 was significantly slower than M. ruber M7, little conidia and ascospores can be observed in Δmrypt7, but the yield of intracellular secondary metabolites was dramatically increased. Simultaneously, the mrypt7 overexpression strain possessed similar capacity for sporulation and secondary metabolism observed in M. ruber M7. Transcriptome results further illustrated that mrypt7 could coordinate with numerous genes involved in the vegetative growth, conidiogenesis, secondary metabolism biosynthesis and transportation of M. ruber 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 Monascus. It could also improve the understanding of Ypt7 functions in fungi.
Highlights
The largest subfamily of rat sarcoma (Ras) superfamily, ras-associated binding GTPases (Rab), called as Ypt and Sec (Gallwitz et al, 1983; Salminen and Novick, 1987), are involved in the membrane trafficking regulation in all eukaryotes (Maringer et al, 2016; Shinde and Maddika, 2016; Yun et al, 2016; Pfeffer, 2017)
The Ypt family genes in M. ruber M7 genome were blasted from NCBI, totally 7 Ypts showed highly homologous with other fungi (Table S1)
What’s interesting is that the velvet regulators, veA and velB which suppresses conidiation and activation of sexual development (Bayram and Braus, 2012; Park and Yu, 2016) were up-regulated in mrypt7-7d, but little cleistothecia could be found in mrypt7 (Figure 2B), which was different from the results found in Aspergillus nidulan (Kim et al, 2002)
Summary
The largest subfamily of rat sarcoma (Ras) superfamily, ras-associated binding GTPases (Rab), called as Ypt (yeast protein transport) and Sec (secretion) (Gallwitz et al, 1983; Salminen and Novick, 1987), are involved in the membrane trafficking regulation in all eukaryotes (Maringer et al, 2016; Shinde and Maddika, 2016; Yun et al, 2016; Pfeffer, 2017). Rab GTPase possess several conserved functional regions, including phosphate/Mg2+ binding domain(PM), GTP/GDP binding domain (G), C-terminal isoprenylation region (C), and so on. The more detailed Ypts roles for vesicle transports in animal and plant are summarized in the previous reviews (Stenmark, 2009; Ao et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
