1
|
Song H, Bao Y, Zhang M, Liu S, Yu C, Dai J, Wu C, Tang D, Fang W. An inactivating mutation in the vacuolar arginine exporter gene Vae results in culture degeneration in the fungus Metarhizium robertsii. Environ Microbiol 2022; 24:2924-2937. [PMID: 35352870 DOI: 10.1111/1462-2920.15982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 03/03/2022] [Accepted: 03/20/2022] [Indexed: 02/04/2023]
Abstract
Culture degeneration usually results in great commercial losses in the economically important filamentous fungi, but the genetic causes of the degeneration remain elusive. In the fungus Metarhizium robertsii, we found that deletion of the vacuolar arginine exporter gene Vae caused culture degeneration. Compared to the WT strain, the mutant showed increased apoptosis, reactive oxygen species (ROS) level and mitochondrial membrane potential collapse, reduced conidial yield and abnormal lipid droplet formation. The extent of the degeneration in the mutant gradually increased over the successive subculturing, which eventually became irreversible; compared to the third subculture of the mutant, the seventh subculture showed a lower conidial yield and pathogenicity to insects, stronger apoptosis, higher ROS level and a smaller number of conidial lipid droplets. Incorporation of the genomic clone of Vae could not restore the WT phenotypes in the seventh subculture, but could in the third one. Loss-of-function in Vae resulted in vacuolar arginine accumulation and reduction in the cytosolic arginine. This downregulated the expression of the regulator CAG9 of G protein signalling pathway, which accounted for most of the phenotypic changes associated with the degeneration of the mutant. We identified a deleterious mutation that causes culture degeneration in a filamentous fugus.
Collapse
Affiliation(s)
- Hui Song
- MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, China
| | - Yuting Bao
- MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, China
| | - Mingxiang Zhang
- MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, China
| | - Shuxing Liu
- MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, China
| | - Chaonan Yu
- MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, China
| | - Jin Dai
- MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, China
| | - Congcong Wu
- MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, China
| | - Dan Tang
- MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, China
| | - Weiguo Fang
- MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, China
| |
Collapse
|
2
|
Kawano-Kawada M, Ichimura H, Ohnishi S, Yamamoto Y, Kawasaki Y, Sekito T. Ygr125w/Vsb1-dependent accumulation of basic amino acids into vacuoles of Saccharomyces cerevisiae. Biosci Biotechnol Biochem 2021; 85:1157-1164. [PMID: 33704406 DOI: 10.1093/bbb/zbab015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 01/20/2021] [Indexed: 01/23/2023]
Abstract
The Ygr125w was previously identified as a vacuolar membrane protein by a proteomic analysis. We found that vacuolar levels of basic amino acids drastically decreased in ygr125wΔ cells. Since N- or C-terminally tagged Ygr125w was not functional, an expression plasmid of YGR125w with HA3-tag inserted in its N-terminal hydrophilic region was constructed. Introduction of this plasmid into ygr125w∆ cells restored the vacuolar levels of basic amino acids. We successfully detected the uptake activity of arginine by the vacuolar membrane vesicles depending on HA3-YGR125w expression. A conserved aspartate residue in the predicted first transmembrane helix (D223) was indispensable for the accumulation of basic amino acids. YGR125w has been recently reported as a gene involved in vacuolar storage of arginine; and it is designated as VSB1. Taken together, our findings indicate that Ygr125w/Vsb1 contributes to the uptake of arginine into vacuoles and vacuolar compartmentalization of basic amino acids.
Collapse
Affiliation(s)
- Miyuki Kawano-Kawada
- Laboratory of Molecular Physiology and Genetics, Graduate School of Agriculture, Ehime University, Matsuyama, Japan.,Division of Cell-Free Life Sciences, Proteo-Science Center, Ehime University, Matsuyama, Japan.,Advanced Research Support Center (ADRES), Ehime University, Matsuyama, Japan
| | - Haruka Ichimura
- Laboratory of Molecular Physiology and Genetics, Graduate School of Agriculture, Ehime University, Matsuyama, Japan
| | - Shota Ohnishi
- Laboratory of Molecular Physiology and Genetics, Faculty of Agriculture, Ehime University, Matsuyama, Japan
| | - Yusuke Yamamoto
- Laboratory of Molecular Physiology and Genetics, Faculty of Agriculture, Ehime University, Matsuyama, Japan
| | - Yumi Kawasaki
- Laboratory of Molecular Physiology and Genetics, Graduate School of Agriculture, Ehime University, Matsuyama, Japan
| | - Takayuki Sekito
- Laboratory of Molecular Physiology and Genetics, Graduate School of Agriculture, Ehime University, Matsuyama, Japan.,Division of Cell-Free Life Sciences, Proteo-Science Center, Ehime University, Matsuyama, Japan
| |
Collapse
|