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Zheng JX, Du TY, Shao GC, Ma ZH, Jiang ZD, Hu W, Suo F, He W, Dong MQ, Du LL. Ubiquitination-mediated Golgi-to-endosome sorting determines the toxin-antidote duality of fission yeast wtf meiotic drivers. Nat Commun 2023; 14:8334. [PMID: 38097609 PMCID: PMC10721834 DOI: 10.1038/s41467-023-44151-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 12/01/2023] [Indexed: 12/17/2023] Open
Abstract
Killer meiotic drivers (KMDs) skew allele transmission in their favor by killing meiotic progeny not inheriting the driver allele. Despite their widespread presence in eukaryotes, the molecular mechanisms behind their selfish behavior are poorly understood. In several fission yeast species, single-gene KMDs belonging to the wtf gene family exert selfish killing by expressing a toxin and an antidote through alternative transcription initiation. Here we investigate how the toxin and antidote products of a wtf-family KMD gene can act antagonistically. Both the toxin and the antidote are multi-transmembrane proteins, differing only in their N-terminal cytosolic tails. We find that the antidote employs PY motifs (Leu/Pro-Pro-X-Tyr) in its N-terminal cytosolic tail to bind Rsp5/NEDD4 family ubiquitin ligases, which ubiquitinate the antidote. Mutating PY motifs or attaching a deubiquitinating enzyme transforms the antidote into a toxic protein. Ubiquitination promotes the transport of the antidote from the trans-Golgi network to the endosome, thereby preventing it from causing toxicity. A physical interaction between the antidote and the toxin enables the ubiquitinated antidote to translocate the toxin to the endosome and neutralize its toxicity. We propose that post-translational modification-mediated protein localization and/or activity changes may be a common mechanism governing the antagonistic duality of single-gene KMDs.
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Affiliation(s)
- Jin-Xin Zheng
- National Institute of Biological Sciences, Beijing, 102206, China
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Tong-Yang Du
- National Institute of Biological Sciences, Beijing, 102206, China
- College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Guang-Can Shao
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Zhu-Hui Ma
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Zhao-Di Jiang
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Wen Hu
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Fang Suo
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Wanzhong He
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, 102206, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, 102206, China.
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, 102206, China.
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2
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Farini D, De Felici M. The Beginning of Meiosis in Mammalian Female Germ Cells: A Never-Ending Story of Intrinsic and Extrinsic Factors. Int J Mol Sci 2022; 23:ijms232012571. [PMID: 36293427 PMCID: PMC9604137 DOI: 10.3390/ijms232012571] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/06/2022] [Accepted: 10/18/2022] [Indexed: 11/16/2022] Open
Abstract
Meiosis is the unique division of germ cells resulting in the recombination of the maternal and paternal genomes and the production of haploid gametes. In mammals, it begins during the fetal life in females and during puberty in males. In both cases, entering meiosis requires a timely switch from the mitotic to the meiotic cell cycle and the transition from a potential pluripotent status to meiotic differentiation. Revealing the molecular mechanisms underlying these interrelated processes represents the essence in understanding the beginning of meiosis. Meiosis facilitates diversity across individuals and acts as a fundamental driver of evolution. Major differences between sexes and among species complicate the understanding of how meiosis begins. Basic meiotic research is further hindered by a current lack of meiotic cell lines. This has been recently partly overcome with the use of primordial-germ-cell-like cells (PGCLCs) generated from pluripotent stem cells. Much of what we know about this process depends on data from model organisms, namely, the mouse; in mice, the process, however, appears to differ in many aspects from that in humans. Identifying the mechanisms and molecules controlling germ cells to enter meiosis has represented and still represents a major challenge for reproductive medicine. In fact, the proper execution of meiosis is essential for fertility, for maintaining the integrity of the genome, and for ensuring the normal development of the offspring. The main clinical consequences of meiotic defects are infertility and, probably, increased susceptibility to some types of germ-cell tumors. In the present work, we report and discuss data mainly concerning the beginning of meiosis in mammalian female germ cells, referring to such process in males only when pertinent. After a brief account of this process in mice and humans and an historical chronicle of the major hypotheses and progress in this topic, the most recent results are reviewed and discussed.
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Meiosis initiation: a story of two sexes in all creatures great and small. Biochem J 2021; 478:3791-3805. [PMID: 34709374 PMCID: PMC8589329 DOI: 10.1042/bcj20210412] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/29/2021] [Accepted: 10/06/2021] [Indexed: 12/22/2022]
Abstract
Meiosis facilitates diversity across individuals and serves as a major driver of evolution. However, understanding how meiosis begins is complicated by fundamental differences that exist between sexes and species. Fundamental meiotic research is further hampered by a current lack of human meiotic cells lines. Consequently, much of what we know relies on data from model organisms. However, contextualising findings from yeast, worms, flies and mice can be challenging, due to marked differences in both nomenclature and the relative timing of meiosis. In this review, we set out to combine current knowledge of signalling and transcriptional pathways that control meiosis initiation across the sexes in a variety of organisms. Furthermore, we highlight the emerging links between meiosis initiation and oncogenesis, which might explain the frequent re-expression of normally silent meiotic genes in a variety of human cancers.
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4
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Regulation of inorganic polyphosphate is required for proper vacuolar proteolysis in fission yeast. J Biol Chem 2021; 297:100891. [PMID: 34147496 PMCID: PMC8294586 DOI: 10.1016/j.jbc.2021.100891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 06/07/2021] [Accepted: 06/16/2021] [Indexed: 02/08/2023] Open
Abstract
Regulation of cellular proliferation and quiescence is a central issue in biology that has been studied using model unicellular eukaryotes, such as the fission yeast Schizosaccharomyces pombe. We previously reported that the ubiquitin/proteasome pathway and autophagy are essential to maintain quiescence induced by nitrogen deprivation in S. pombe; however, specific ubiquitin ligases that maintain quiescence are not fully understood. Here we investigated the SPX-RING-type ubiquitin ligase Pqr1, identified as required for quiescence in a genetic screen. Pqr1 is found to be crucial for vacuolar proteolysis, the final step of autophagy, through proper regulation of phosphate and its polymer polyphosphate. Pqr1 restricts phosphate uptake into the cell through ubiquitination and subsequent degradation of phosphate transporters on plasma membranes. We hypothesized that Pqr1 may act as the central regulator for phosphate control in S. pombe, through the function of the SPX domain involved in phosphate sensing. Deletion of pqr1+ resulted in hyperaccumulation of intracellular phosphate and polyphosphate and in improper autophagy-dependent proteolysis under conditions of nitrogen starvation. Polyphosphate hyperaccumulation in pqr1+-deficient cells was mediated by the polyphosphate synthase VTC complex in vacuoles. Simultaneous deletion of VTC complex subunits rescued Pqr1 mutant phenotypes, including defects in proteolysis and loss of viability during quiescence. We conclude that excess polyphosphate may interfere with proteolysis in vacuoles by mechanisms that as yet remain unknown. The present results demonstrate a connection between polyphosphate metabolism and vacuolar functions for proper autophagy-dependent proteolysis, and we propose that polyphosphate homeostasis contributes to maintenance of cellular viability during quiescence.
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5
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Lin J, Yan H, Zhao L, Li Y, Nahidian B, Zhu M, Hu Q, Han D. Interaction between the cell walls of microalgal host and fungal carbohydrate-activate enzymes is essential for the pathogenic parasitism process. Environ Microbiol 2021; 23:5114-5130. [PMID: 33723900 DOI: 10.1111/1462-2920.15465] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 02/07/2021] [Accepted: 03/13/2021] [Indexed: 12/22/2022]
Abstract
Fungi can parasitize microalgae, exerting profound impacts on both the aquatic ecosystems and microalgal mass cultures. In this study, the unicellular green alga Haematococcus pluvialis and the blastocladialean fungus Paraphysoderma sedebokerense were used as a model system to address the mechanisms underlying the fungal parasitism on the algal host. High-throughput metabolic assay indicated that P. sedebokerense can utilize several carbon sources with a preference for mannose, glucose and their oligosaccharides, which was compatible with the profile of the host algal cell walls enriched with glucan and mannan. The results of dual transcriptomics analysis suggested that P. sedebokerense can upregulate a large number of putative carbohydrate-activate enzymes (CAZymes) encoding genes, including those coding for the endo-1,4-β-glucanase and endo-1,4-β-mannanase during the infection process. The cell walls of H. pluvialis can be decomposed by both P. sedebokerense and commercial CAZymes (e.g. cellulase and endo-1,4-β-mannanase) to produce mannooligomers, while several putative parasitism-related genes of P. sedebokerense can be in turn upregulated by mannooligomers. In addition, the parasitism can be blocked by interfering the selected CAZymes including glucanase, mannanase and lysozyme with the specific inhibitors, which provided a framework for screening suitable compounds for pathogen mitigation in algal mass culture.
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Affiliation(s)
- Juan Lin
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.,State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.,Poyang Lake Eco-economy Research Center, Jiujiang University, Jiujiang, 332005, China
| | - Hailong Yan
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Liang Zhao
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Yanhua Li
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Bahareh Nahidian
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Mianmian Zhu
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qiang Hu
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.,State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.,Institute for Advanced Study, Shenzhen University, Shenzhen, 51806, China.,Key Laboratory for Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Danxiang Han
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.,Key Laboratory for Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
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6
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Jiang G, Liu Q, Kato T, Miao H, Gao X, Liu K, Chen S, Sakamoto N, Kuno T, Fang Y. Role of mitochondrial complex III/IV in the activation of transcription factor Rst2 in Schizosaccharomyces pombe. Mol Microbiol 2021; 115:1323-1338. [PMID: 33400299 DOI: 10.1111/mmi.14678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/31/2020] [Accepted: 12/31/2020] [Indexed: 11/30/2022]
Abstract
Mitochondria play essential roles in eukaryotic cells for glucose metabolism to produce ATP. In Schizosaccharomyces pombe, transcription factor Rst2 can be activated upon glucose deprivation. However, the link between Rst2 and mitochondrial function remains elusive. Here, we monitored Rst2 transcriptional activity in living cells using a Renilla luciferase reporter system, and found that inhibition of mitochondrial complex III/IV caused cells to produce reactive oxygen species (ROS) and nitric oxide (NO), which in turn activated Rst2. Furthermore, Rst2-GFP was observed to translocate from cytoplasm to nucleus upon mitochondrial complex III/IV inhibitors treatment, and deletion of genes associated with complex III/IV resulted in delayed process of Rst2-GFP nuclear exportation under glucose-rich condition. In particular, we found that Rst2 was phosphorylated following the treatment of complex III/IV inhibitors or SNAP. Altogether, our findings suggest that mitochondrial complex III/IV participates in the activation of Rst2 through ROS and NO generation in Schizosaccharomyces pombe.
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Affiliation(s)
- Guanglie Jiang
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, China Medical University, Shenyang, China
| | - Qiannan Liu
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, China Medical University, Shenyang, China
| | - Toshiaki Kato
- Division of Food and Drug Evaluation Science, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hao Miao
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, China Medical University, Shenyang, China
| | - Xiang Gao
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, China Medical University, Shenyang, China
| | - Kun Liu
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, China Medical University, Shenyang, China
| | - Si Chen
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, China Medical University, Shenyang, China
| | - Norihiro Sakamoto
- Division of Food and Drug Evaluation Science, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Takayoshi Kuno
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, China Medical University, Shenyang, China.,Division of Food and Drug Evaluation Science, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yue Fang
- Department of Microbial and Biochemical Pharmacy, School of Pharmacy, China Medical University, Shenyang, China
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7
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Hu YM, Boehm DM, Chung H, Wilson S, Bird AJ. Zinc-dependent activation of the Pho8 alkaline phosphatase in Schizosaccharomyces pombe. J Biol Chem 2019; 294:12392-12404. [PMID: 31239353 PMCID: PMC6699849 DOI: 10.1074/jbc.ra119.007371] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 06/20/2019] [Indexed: 01/23/2023] Open
Abstract
Genome-wide analyses have revealed that during metal ion starvation, many cells undergo programmed changes in their transcriptome or proteome that lower the levels of abundant metalloproteins, conserving metal ions for more critical functions. Here we investigated how changes in cellular zinc status affect the expression and activity of the zinc-requiring Pho8 alkaline phosphatase from fission yeast (Schizosaccharomyces pombe). In S. pombe, Pho8 is a membrane-tethered and processed glycoprotein that resides in the vacuole. Using alkaline phosphatase activity assays along with various biochemical analyses, we found that Pho8 is active when zinc is plentiful and inactive when zinc is limited. Although Pho8 activity depended on zinc, we also found that higher levels of pho8 mRNAs and Pho8 protein accumulate in zinc-deficient cells. To gain a better understanding of the inverse relationship between pho8 mRNA levels and Pho8 activity, we examined the effects of zinc on the stability and processing of the Pho8 protein. We show that Pho8 is processed regardless of zinc status and that mature Pho8 accumulates under all conditions. We also noted that alkaline phosphatase activity is rapidly restored when zinc is resupplied to cells, even in the presence of the protein synthesis inhibitor cycloheximide. Our results suggest that S. pombe cells maintain inactive pools of Pho8 proteins under low-zinc conditions and that these pools facilitate rapid restoration of Pho8 activity when zinc ions become available.
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Affiliation(s)
- Ya-Mei Hu
- Department of Human Nutrition, Ohio State University, Columbus, Ohio 43210
| | - Derek M Boehm
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Hak Chung
- Ohio State University Interdisciplinary Nutrition Program, Ohio State University, Columbus, Ohio 43210
| | - Stevin Wilson
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Amanda J Bird
- Department of Human Nutrition, Ohio State University, Columbus, Ohio 43210; Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210; Center for RNA Biology, Ohio State University, Columbus, Ohio 43210.
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8
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Yanguas F, Moscoso-Romero E, Valdivieso MH. Ent3 and GGA adaptors facilitate diverse anterograde and retrograde trafficking events to and from the prevacuolar endosome. Sci Rep 2019; 9:10747. [PMID: 31341193 PMCID: PMC6656748 DOI: 10.1038/s41598-019-47035-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 07/09/2019] [Indexed: 11/09/2022] Open
Abstract
Carboxypeptidases Y (Cpy1) and S (Cps1), the receptor Vps10, and the ATPase subunit Vph1 follow the carboxypeptidase Y (CPY) pathway from the trans-Golgi network (TGN) to the prevacuolar endosome (PVE). Using Schizosaccharomyces pombe quantitative live-cell imaging, biochemical and genetic analyses, we extended the previous knowledge and showed that collaboration between Gga22, the dominant Golgi-localized Gamma-ear-containing ARF-binding (GGA) protein, and Gga21, and between Gga22 and the endosomal epsin Ent3, was required for efficient: i) Vps10 anterograde trafficking from the TGN to the PVE; ii) Vps10 retrograde trafficking from the PVE to the TGN; iii) Cps1 exit from the TGN, and its sorting in the PVE en route to the vacuole; and iv) Syb1/Snc1 recycling to the plasma membrane through the PVE. Therefore, monomeric clathrin adaptors facilitated the trafficking of Vps10 in both directions of the CPY pathway, and facilitated trafficking events of Cps1 in different organelles. By contrast, they were dispensable for Vph1 trafficking. Thus, these adaptors regulated the traffic of some, but not all, of the cargo of the CPY pathway, and regulated the traffic of cargoes that do not follow this pathway. Additionally, this collaboration was required for PVE organization and efficient growth under stress.
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Affiliation(s)
- Francisco Yanguas
- Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain.,Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas (CSIC), Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Esteban Moscoso-Romero
- Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain.,Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas (CSIC), Calle Zacarías González 2, 37007, Salamanca, Spain
| | - M-Henar Valdivieso
- Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain. .,Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas (CSIC), Calle Zacarías González 2, 37007, Salamanca, Spain.
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9
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Paulus JK, Van der Hoorn RAL. Do proteolytic cascades exist in plants? JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1997-2002. [PMID: 30668744 PMCID: PMC6460957 DOI: 10.1093/jxb/erz016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/15/2018] [Accepted: 01/08/2019] [Indexed: 05/10/2023]
Affiliation(s)
- Judith K Paulus
- The Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, Oxford, UK
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10
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Liu Q, Ma Y, Zhou X, Furuyashiki T. Constitutive Tor2 Activity Promotes Retention of the Amino Acid Transporter Agp3 at Trans-Golgi/Endosomes in Fission Yeast. PLoS One 2015; 10:e0139045. [PMID: 26447710 PMCID: PMC4598100 DOI: 10.1371/journal.pone.0139045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/07/2015] [Indexed: 12/13/2022] Open
Abstract
Amino acid transporters are located at specific subcellular compartments, and their localizations are regulated by the extracellular availability of amino acids. In yeast, target of rapamycin (TOR) activation induces the internalization of amino acid transporters located at the plasma membrane. However, whether and how TOR signaling regulates other amino acid transporters located at intracellular compartments remains unknown. Here, we demonstrate that in the fission yeast, the TOR inhibitor Torin-1 induces the transfer of several yellow fluorescent protein (YFP)-fused intracellular amino acid transporters, including Agp3, Isp5, Aat1, and Put4, from trans-Golgi/endosomes into the vacuoles. By contrast, the localizations of YFP-fused Can1, Fnx1, and Fnx2 transporter proteins were unaffected upon Torin-1 treatment. There are two TOR isoforms in fission yeast, Tor1 and Tor2. Whereas tor1 deletion did not affect the Torin-1-induced transfer of Agp3-YFP, Tor2 inhibition using a temperature-sensitive mutant induced the transfer of Agp3-YFP to the vacuolar lumen, similar to the effects of Torin-1 treatment. Tor2 inhibition also induced the transfer of the YFP-fused Isp5, Aat1, and Put4 transporter proteins to the vacuoles, although only partial transfer of the latter two transporters was observed. Under nitrogen depletion accompanied by reduced Tor2 activity, Agp3-YFP was transferred from the trans-Golgi/endosomes to the plasma membrane and then to the vacuoles, where it was degraded by the vacuolar proteases Isp6 and Psp3. Mutants with constitutively active Tor2 showed delayed transfer of Agp3-YFP to the plasma membrane upon nitrogen depletion. Cells lacking Tsc2, a negative regulator of Tor2, also showed a delay in this process in a Tor2-dependent manner. Taken together, these findings suggest that constitutive Tor2 activity is critical for the retention of amino acid transporters at trans-Golgi/endosomes. Moreover, nitrogen depletion suppresses Tor2 activity through Tsc2, thereby promoting the surface expression of these transporters.
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Affiliation(s)
- Qingbin Liu
- Division of Pharmacology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yan Ma
- Division of Pharmacology, Kobe University Graduate School of Medicine, Kobe, Japan
- * E-mail:
| | - Xin Zhou
- Department of Oncology, the First Affiliated Hospital of Liaoning Medical University, Jinzhou, China
| | - Tomoyuki Furuyashiki
- Division of Pharmacology, Kobe University Graduate School of Medicine, Kobe, Japan
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Sepúlveda-González ME, Parra-Ortega B, Betancourt-Cervantes Y, Hernández-Rodríguez C, Xicohtencatl-Cortes J, Villa-Tanaca L. Vacuolar proteases from Candida glabrata: Acid aspartic protease PrA, neutral serine protease PrB and serine carboxypeptidase CpY. The nitrogen source influences their level of expression. Rev Iberoam Micol 2015; 33:26-33. [PMID: 26422323 DOI: 10.1016/j.riam.2014.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 08/25/2014] [Accepted: 10/17/2014] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND The Saccharomyces cerevisiae vacuole is actively involved in the mechanism of autophagy and is important in homeostasis, degradation, turnover, detoxification and protection under stressful conditions. In contrast, vacuolar proteases have not been fully studied in phylogenetically related Candida glabrata. AIMS The present paper is the first report on proteolytic activity in the C. glabrata vacuole. METHODS Biochemical studies in C. glabrata have highlighted the presence of different kinds of intracellular proteolytic activity: acid aspartyl proteinase (PrA) acts on substrates such as albumin and denatured acid hemoglobin, neutral serine protease (PrB) on collagen-type hide powder azure, and serine carboxypeptidase (CpY) on N-benzoyl-tyr-pNA. RESULTS Our results showed a subcellular fraction with highly specific enzymatic activity for these three proteases, which allowed to confirm its vacuolar location. Expression analyses were performed in the genes CgPEP4 (CgAPR1), CgPRB1 and CgCPY1 (CgPRC), coding for vacuolar aspartic protease A, neutral protease B and carboxypeptidase Y, respectively. The results show a differential regulation of protease expression depending on the nitrogen source. CONCLUSIONS The proteases encoded by genes CgPEP4, CgPRB1 and CgCPY1 from C. glabrata could participate in the process of autophagy and survival of this opportunistic pathogen.
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Affiliation(s)
- M Eugenia Sepúlveda-González
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico; Laboratorio de Investigación en Bacteriología Intestinal, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez, Delegación Cuauhtémoc, México, D.F., Mexico
| | - Berenice Parra-Ortega
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico
| | - Yuliana Betancourt-Cervantes
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico
| | - César Hernández-Rodríguez
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico
| | - Juan Xicohtencatl-Cortes
- Laboratorio de Investigación en Bacteriología Intestinal, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez, Delegación Cuauhtémoc, México, D.F., Mexico.
| | - Lourdes Villa-Tanaca
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico.
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12
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Revuelta MV, van Kan JAL, Kay J, Ten Have A. Extensive expansion of A1 family aspartic proteinases in fungi revealed by evolutionary analyses of 107 complete eukaryotic proteomes. Genome Biol Evol 2015; 6:1480-94. [PMID: 24869856 PMCID: PMC4079213 DOI: 10.1093/gbe/evu110] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The A1 family of eukaryotic aspartic proteinases (APs) forms one of the 16 AP families. Although one of the best characterized families, the recent increase in genome sequence data has revealed many fungal AP homologs with novel sequence characteristics. This study was performed to explore the fungal AP sequence space and to obtain an in-depth understanding of fungal AP evolution. Using a comprehensive phylogeny of approximately 700 AP sequences from the complete proteomes of 87 fungi and 20 nonfungal eukaryotes, 11 major clades of APs were defined of which clade I largely corresponds to the A1A subfamily of pepsin-archetype APs. Clade II largely corresponds to the A1B subfamily of nepenthesin-archetype APs. Remarkably, the nine other clades contain only fungal APs, thus indicating that fungal APs have undergone a large sequence diversification. The topology of the tree indicates that fungal APs have been subject to both “birth and death” evolution and “functional redundancy and diversification.” This is substantiated by coclustering of certain functional sequence characteristics. A meta-analysis toward the identification of Cluster Determining Positions (CDPs) was performed in order to investigate the structural and biochemical basis for diversification. Seven CDPs contribute to the secondary structure of the enzyme. Three other CDPs are found in the vicinity of the substrate binding cleft. Tree topology, the large sequence variation among fungal APs, and the apparent functional diversification suggest that an amendment to update the current A1 AP classification based on a comprehensive phylogenetic clustering might contribute to refinement of the classification in the MEROPS peptidase database.
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Affiliation(s)
- María V Revuelta
- Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Jan A L van Kan
- Laboratory of Phytopathology, Wageningen University, The Netherlands
| | - John Kay
- School of Biosciences, Cardiff University, United Kingdom
| | - Arjen Ten Have
- Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
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Núñez A, Dulude D, Jbel M, Rokeach LA. Calnexin is essential for survival under nitrogen starvation and stationary phase in Schizosaccharomyces pombe. PLoS One 2015; 10:e0121059. [PMID: 25803873 PMCID: PMC4372366 DOI: 10.1371/journal.pone.0121059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 02/06/2015] [Indexed: 12/04/2022] Open
Abstract
Cell fate is determined by the balance of conserved molecular mechanisms regulating death (apoptosis) and survival (autophagy). Autophagy is a process by which cells recycle their organelles and macromolecules through degradation within the vacuole in yeast and plants, and lysosome in metazoa. In the yeast Schizosaccharomyces pombe, autophagy is strongly induced under nitrogen starvation and in aging cells. Previously, we demonstrated that calnexin (Cnx1p), a highly conserved transmembrane chaperone of the endoplasmic reticulum (ER), regulates apoptosis under ER stress or inositol starvation. Moreover, we showed that in stationary phase, Cnx1p is cleaved into two moieties, L_Cnx1p and S_Cnx1p. Here, we show that the processing of Cnx1p is regulated by autophagy, induced by nitrogen starvation or cell aging. The cleavage of Cnx1p involves two vacuolar proteases: Isp6, which is essential for autophagy, and its paralogue Psp3. Blocking autophagy through the knockout of autophagy-related genes (atg) results in inhibition of both, the cleavage and the trafficking of Cnx1p from the ER to the vacuole. We demonstrate that Cnx1p is required for cell survival under nitrogen-starvation and in chronological aging cultures. The death of the mini_cnx1 mutant (overlapping S_cnx1p) cells is accompanied by accumulation of high levels of reactive-oxygen species (ROS), a slowdown in endocytosis and severe cell-wall defects. Moreover, mutant cells expressing only S_Cnx1p showed cell wall defects. Co-expressing mutant overlapping the L_Cnx1p and S_Cnx1p cleavage products reverses the death, ROS phenotype and cell wall defect to wild-type levels. As it is involved in both apoptosis and autophagy, Cnx1p could be a nexus for the crosstalk between these pro-death and pro-survival mechanisms. Ours, and observations in mammalian systems, suggest that the multiple roles of calnexin depend on its sub-cellular localization and on its cleavage. The use of S. pombe should assist in further shedding light on the multiple roles of calnexin.
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Affiliation(s)
- Andrés Núñez
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Dominic Dulude
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Mehdi Jbel
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Luis A. Rokeach
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
- * E-mail:
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Yu X, Zhai C, Zhong X, Tang W, Wang X, Yang H, Chen W, Ma L. High-level expression and characterization of carboxypeptidase Y from Saccharomyces cerevisiae in Pichia pastoris GS115. Biotechnol Lett 2014; 37:161-7. [DOI: 10.1007/s10529-014-1667-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 09/04/2014] [Indexed: 12/01/2022]
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GPI (glycosylphosphatidylinositol)-linked aspartyl proteases regulate vacuole homoeostasis in Candida glabrata. Biochem J 2014; 458:323-34. [PMID: 24341558 DOI: 10.1042/bj20130757] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A family of 11 GPI (glycosylphosphatidylinositol)-linked cell surface-associated aspartyl proteases (yapsins) in the human opportunistic fungal pathogen Candida glabrata is required for cell wall remodelling, pH homoeostasis, survival in macrophages and virulence in a murine model of disseminated candidiasis. In the present paper, we report new roles for yapsins in C. glabrata physiology and implicate them for the first time in the regulation of vacuole homoeostasis. In the present study we show that a C. glabrata mutant lacking all 11 yapsins, Cgyps1-11∆, possesses an enlarged vacuole and displays vma- (vacuolar membrane ATPase)-like phenotypes with elevated metal ion susceptibility in an alkaline pH medium and diminished Vma activity. The results of the present study also demonstrate a singular role for CgYps1 (C. glabrata yapsin 1) in the maintenance of ion homoeostasis under normal and calcineurin-inhibited conditions. Elevated polyphosphate levels and diminished cellular CPY (carboxypeptidase Y) activity in the Cgyps1-11∆ mutant highlight the yapsin requirement for a properly functioning vacuole. Lastly, a gross perturbation of cellular homoeostasis in the Cgyps1-11∆ mutant, even in the absence of external stressors, characterized by reduced levels of ATP and stress metabolites, elevated ROS (reactive oxygen species) levels, cell surface abnormalities, and a constitutively activated PKC (protein kinase C) signalling pathway underscore diverse physiological functions of yapsins in C. glabrata.
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pH-dependent activation of Streptomyces hygroscopicus transglutaminase mediated by intein. Appl Environ Microbiol 2013; 80:723-9. [PMID: 24242235 DOI: 10.1128/aem.02820-13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial transglutaminase (MTG) from Streptomyces is naturally secreted as a zymogen (pro-MTG), which is then activated by the removal of its N-terminal proregion by additional proteases. Inteins are protein-intervening sequences that catalyze protein splicing without cofactors. In this study, a pH-dependent Synechocystis sp. strain PCC6803 DnaB mini-intein (SDB) was introduced into pro-MTG to simplify its activation process by controlling pH. The recombinant protein (pro-SDB-MTG) was obtained, and the activation process was determined to take 24 h at pH 7 in vitro. To investigate the effect of the first residue in MTG on the activity and the cleavage time, two variants, pro-SDB-MTG(D1S) and pro-SDB-MTG(ΔD1), were expressed, and the activation time was found to be 6 h and 30 h, respectively. The enzymatic property and secondary structure of the recombinant MTG and two variants were similar to those of the wild type, indicating that the insertion of mini-intein did not affect the function of MTG. This insignificant effect was further illustrated by molecular dynamics simulations. This study revealed a controllable and effective strategy to regulate the activation process of pro-MTG mediated by a mini-intein, and it may have great potential for industrial MTG production.
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