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Gong X, Srivastava V, Naicker P, Khan A, Ahmad A. Candida parapsilosis Cell Wall Proteome Characterization and Effectiveness against Hematogenously Disseminated Candidiasis in a Murine Model. Vaccines (Basel) 2023; 11:vaccines11030674. [PMID: 36992262 DOI: 10.3390/vaccines11030674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 03/19/2023] Open
Abstract
Candida parapsilosis poses huge treatment challenges in the clinical settings of South Africa, and often causes infections among immunocompromised patients and underweight neonates. Cell wall proteins have been known to play vital roles in fungal pathogenesis, as these are the first points of contact toward environments, the host, and the immune system. This study characterized the cell wall immunodominant proteins of pathogenic yeast C. parapsilosis and evaluated their protective effects in mice, which could add value in vaccine development against the rising C. parapsilosis infections. Among different clinical strains, the most pathogenic and multidrug-resistant C. parapsilosis isolate was selected based on their susceptibility towards antifungal drugs, proteinase, and phospholipase secretions. Cell wall antigens were prepared by β-mercaptoethanol/ammonium bicarbonate extraction from selected C. parapsilosis strains. Antigenic proteins were identified using LC–MS/MS, where 933 proteins were found, with 34 being immunodominant. The protective effect of the cell wall immunodominant proteins was observed by immunizing BALB/c mice with cell wall protein extracts. After the immunization and booster, the BALC/c mice were challenged with a lethal dose of C. parapsilosis. In vivo results demonstrated increased survival rates and lower fungal burden in vital organs in the immunized mice compared to the unimmunized mice, thereby confirming the immunogenic property of cell wall-associated proteins of C. parapsilosis. Therefore, these results advocated the potential of these cell wall proteins to act as biomarkers for the development of diagnostic assays and/or vaccines against infections caused by C. parapsilosis.
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Affiliation(s)
- Xiaolong Gong
- Clinical Microbiology and Infectious Diseases, School of Pathology, Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Vartika Srivastava
- Clinical Microbiology and Infectious Diseases, School of Pathology, Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Previn Naicker
- NextGen Health, Council for Scientific and Industrial Research, Pretoria 0184, South Africa
| | - Amber Khan
- The Scintillon Institute, 6404 Nancy Ridge Drive, San Diego, CA 92121, USA
| | - Aijaz Ahmad
- Clinical Microbiology and Infectious Diseases, School of Pathology, Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
- Infection Control, Charlotte Maxeke Johannesburg Academic Hospital, National Health Laboratory Service, Johannesburg 2193, South Africa
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Mercado-Flores Y, Hernández-Rodríguez C, Ruiz-Herrera J, Villa-Tanaca L. Proteinases and exopeptidases from the phytopathogenic fungusUstilago maydis. Mycologia 2017. [DOI: 10.1080/15572536.2004.11833118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - César Hernández-Rodríguez
- Departamento de Microbiología. Escuela Nacional de Ciencias Biológicas, IPN. Casco de Santo Tomás. México DF
| | - José Ruiz-Herrera
- Departamento de Ingeniería Genética, Unidad Irapuato, Centro de Investigación y Estudios Avanzados, IPN. Irapuato, Guanajuato, México
| | - Lourdes Villa-Tanaca
- Departamento de Microbiología. Escuela Nacional de Ciencias Biológicas, IPN. Casco de Santo Tomás. México DF
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Møller TSB, Hay J, Saxton MJ, Bunting K, Petersen EI, Kjærulff S, Finnis CJA. Human β-defensin-2 production from S. cerevisiae using the repressible MET17 promoter. Microb Cell Fact 2017; 16:11. [PMID: 28100236 PMCID: PMC5241953 DOI: 10.1186/s12934-017-0627-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 01/08/2017] [Indexed: 11/25/2022] Open
Abstract
Background Baker’s yeast Saccharomyces cerevisiae is a proven host for the commercial production of recombinant biopharmaceutical proteins. For the manufacture of heterologous proteins with activities deleterious to the host it can be desirable to minimise production during the growth phase and induce production late in the exponential phase. Protein expression by regulated promoter systems offers the possibility of improving productivity in this way by separating the recombinant protein production phase from the yeast growth phase. Commonly used inducible promoters do not always offer convenient solutions for industrial scale biopharmaceutical production with engineered yeast systems. Results Here we show improved secretion of the antimicrobial protein, human β-defensin-2, (hBD2), using the S. cerevisiae MET17 promoter by repressing expression during the growth phase. In shake flask culture, a higher final concentration of human β-defensin-2 was obtained using the repressible MET17 promoter system than when using the strong constitutive promoter from proteinase B (PRB1) in a yeast strain developed for high-level commercial production of recombinant proteins. Furthermore, this was achieved in under half the time using the MET17 promoter compared to the PRB1 promoter. Cell density, plasmid copy-number, transcript level and protein concentration in the culture supernatant were used to study the effects of different initial methionine concentrations in the culture media for the production of human β-defensin-2 secreted from S. cerevisiae. Conclusions The repressible S. cerevisiae MET17 promoter was more efficient than a strong constitutive promoter for the production of human β-defensin-2 from S. cerevisiae in small-scale culture and offers advantages for the commercial production of this and other heterologous proteins which are deleterious to the host organism. Furthermore, the MET17 promoter activity can be modulated by methionine alone, which has a safety profile applicable to biopharmaceutical manufacturing.
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Affiliation(s)
- Thea S B Møller
- Novozymes Biopharma UK Limited, Castle Court, 59 Castle Boulevard, Nottingham, NG7 1FD, UK.,Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, Aalborg East, 9220, Aalborg, Denmark
| | - Joanna Hay
- Novozymes Biopharma UK Limited, Castle Court, 59 Castle Boulevard, Nottingham, NG7 1FD, UK
| | - Malcolm J Saxton
- Novozymes Biopharma UK Limited, Castle Court, 59 Castle Boulevard, Nottingham, NG7 1FD, UK
| | - Karen Bunting
- Novozymes Biopharma UK Limited, Castle Court, 59 Castle Boulevard, Nottingham, NG7 1FD, UK
| | - Evamaria I Petersen
- Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, Aalborg East, 9220, Aalborg, Denmark
| | - Søren Kjærulff
- Novozymes Biopharma UK Limited, Castle Court, 59 Castle Boulevard, Nottingham, NG7 1FD, UK
| | - Christopher J A Finnis
- Novozymes Biopharma UK Limited, Castle Court, 59 Castle Boulevard, Nottingham, NG7 1FD, UK.
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Tran LM, Bang SH, Yoon J, Kim Y, Min J. Effect of GTP-binding protein (YPT1 protein) on the enhanced yeast vacuolar activity. Mol Cell Biochem 2016; 414:179-86. [DOI: 10.1007/s11010-016-2670-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 02/13/2016] [Indexed: 10/22/2022]
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Abstract
Meiosis, the developmental programme generating haploid gametes from diploid precursors, requires two cell divisions and many innovations. In budding yeast, a large number of genes are expressed exclusively during meiosis while others are repressed compared to vegetative growth. Microarray analysis has shown that gene expression during meiosis is highly regulated, and has been used to classify yeast genes according to meiotic temporal expression pattern. In this study, we have begun to investigate the kinetics of meiotic protein expression using a proteomics approach. 2-D DIGE was used to characterise the temporal protein expression patterns of the budding yeast pH 4-7 proteome in meiosis. More than 1400 meiotic protein spots were visualised and at least 63 spots were temporally regulated during meiosis in a statistically significant manner. Gel spots with significant expression changes were excised and 26 unique proteins were identified using LC-MS/MS. The identified proteins could be classified into functional categories and the genes encoding a number of these were previously shown to be involved in yeast sporulation and meiosis. This data set was used to assemble the first differential 2-D PAGE map of budding yeast meiosis, which can be accessed through a web server. This work represents one of the first quantitative proteomic analyses of meiosis in yeast and will provide a valuable resource for future investigations.
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Affiliation(s)
- Julia Grassl
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland.
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Rékangalt D, Pépin R, Verner MC, Debaud JC, Marmeisse R, Fraissinet-Tachet L. Expression of the nitrate transporter nrt2 gene from the symbiotic basidiomycete Hebeloma cylindrosporum is affected by host plant and carbon sources. Mycorrhiza 2009; 19:143-148. [PMID: 19125303 DOI: 10.1007/s00572-008-0221-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 12/10/2008] [Indexed: 05/27/2023]
Abstract
Although the function of the extramatrical mycelium of ectomycorrhizal fungi is considered essential for the acquisition of nitrogen by forest trees, gene regulation in this fungal compartment is poorly characterized. In this study, the expression of the nitrate transporter gene nrt2 from the ectomycorrhizal basidiomycete Hebeloma cylindrosporum was shown to be regulated by plant host and carbon sources. In the presence of a low fructose concentration, nrt2 expression could not be detected in the free-living mycelium but was high in the extramatrical symbiotic mycelium associated to the host plant Pinus pinaster. In the absence of nitrogen or in the presence of nitrate, high sugar concentrations in the medium were able to enhance nrt2 expression. Nevertheless, in the presence of high fructose concentration, high ammonium concentration still completely repressed nrt2 expression indicating that the nitrogen repression overrides sugar stimulation. This is the first report revealing an effect of host plant and of carbon sources on the expression of a fungal nitrate transporter-encoding gene.
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Affiliation(s)
- David Rékangalt
- Université de Lyon, 69622, Lyon, France
- CNRS, UMR5557, INRA, USC 1193, Ecologie Microbienne, Bât. Lwoff, Université Lyon 1, 43 boulevard du 11 novembre 1918, 69622, Villeurbanne Cedex, France
| | - Régis Pépin
- Université de Lyon, 69622, Lyon, France
- CNRS, UMR5557, INRA, USC 1193, Ecologie Microbienne, Bât. Lwoff, Université Lyon 1, 43 boulevard du 11 novembre 1918, 69622, Villeurbanne Cedex, France
| | - Marie-Christine Verner
- Université de Lyon, 69622, Lyon, France
- CNRS, UMR5557, INRA, USC 1193, Ecologie Microbienne, Bât. Lwoff, Université Lyon 1, 43 boulevard du 11 novembre 1918, 69622, Villeurbanne Cedex, France
| | - Jean-Claude Debaud
- Université de Lyon, 69622, Lyon, France
- CNRS, UMR5557, INRA, USC 1193, Ecologie Microbienne, Bât. Lwoff, Université Lyon 1, 43 boulevard du 11 novembre 1918, 69622, Villeurbanne Cedex, France
| | - Roland Marmeisse
- Université de Lyon, 69622, Lyon, France
- CNRS, UMR5557, INRA, USC 1193, Ecologie Microbienne, Bât. Lwoff, Université Lyon 1, 43 boulevard du 11 novembre 1918, 69622, Villeurbanne Cedex, France
| | - Laurence Fraissinet-Tachet
- Université de Lyon, 69622, Lyon, France.
- CNRS, UMR5557, INRA, USC 1193, Ecologie Microbienne, Bât. Lwoff, Université Lyon 1, 43 boulevard du 11 novembre 1918, 69622, Villeurbanne Cedex, France.
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Abstract
Heterologous protein production late in Saccharomyces cerevisiae fermentations is often desirable because it may help avoid the unintentional selection of more rapidly growing, non-protein-expressing cells or allow for the expression of toxic proteins. Here, we describe the use of the MET25 promoter for the production of human serum albumin (HSA) and HSA-fusion proteins in S. cerevisiae. In media lacking methionine, the MET25 promoter yielded high expression levels of HSA and HSA fused to human glucagon, human growth hormone, human interferon alpha, and human interleukin-2. More importantly, we have shown that this system can be used to delay heterologous protein production until late log phase of the growth of the culture and does not require the addition of an exogenous inducer.
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Affiliation(s)
- Steven P Solow
- Human Genome Sciences, Inc., Rockville, Maryland 20850, USA.
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Liu Y, Xu X, Singh-Rodriguez S, Zhao Y, Kuo MH. Histone H3 Ser10 phosphorylation-independent function of Snf1 and Reg1 proteins rescues a gcn5- mutant in HIS3 expression. Mol Cell Biol 2005; 25:10566-79. [PMID: 16287868 PMCID: PMC1291248 DOI: 10.1128/mcb.25.23.10566-10579.2005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gcn5 protein is a prototypical histone acetyltransferase that controls transcription of multiple yeast genes. To identify molecular functions that act downstream of or in parallel with Gcn5 protein, we screened for suppressors that rescue the transcriptional defects of HIS3 caused by a catalytically inactive mutant Gcn5, the E173H mutant. One bypass of Gcn5 requirement gene (BGR) suppressor was mapped to the REG1 locus that encodes a semidominant mutant truncated after amino acid 740. Reg1(1-740) protein does not rescue the complete knockout of GCN5, nor does it suppress other gcn5- defects, including the inability to utilize nonglucose carbon sources. Reg1(1-740) enhances HIS3 transcription while HIS3 promoter remains hypoacetylated, indicating that a noncatalytic function of Gcn5 is targeted by this suppressor protein. Reg1 protein is a major regulator of Snf1 kinase that phosphorylates Ser10 of histone H3. However, whereas Snf1 protein is important for HIS3 expression, replacing Ser10 of H3 with alanine or glutamate neither attenuates nor augments the BGR phenotypes. Overproduction of Snf1 protein also preferentially rescues the E173H allele. Biochemically, both Snf1 and Reg1(1-740) proteins copurify with Gcn5 protein. Snf1 can phosphorylate recombinant Gcn5 in vitro. Together, these data suggest that Reg1 and Snf1 proteins function in an H3 phosphorylation-independent pathway that also involves a noncatalytic role played by Gcn5 protein.
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Affiliation(s)
- Yang Liu
- 401 BCH Building, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824.
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Abstract
Known prions (infectious proteins) are self-propagating amyloids or conformationally altered proteins, but in theory an enzyme necessary for its own activation could also be a prion (or a gene composed of protein). We show that yeast protease B is such a prion, called [beta].[beta] is infectious, reversibly curable, and its de novo generation is induced by overexpression of the pro-protease. Present in normal cells but masked by the functionally redundant protease A, [beta] is advantageous during starvation and necessary for sporulation. We propose that other enzymes whose active, modified, form is necessary for their maturation might also be prions.
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Affiliation(s)
- B Tibor Roberts
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA
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Dementhon K, Paoletti M, Pinan-Lucarré B, Loubradou-Bourges N, Sabourin M, Saupe SJ, Clavé C. Rapamycin mimics the incompatibility reaction in the fungus Podospora anserina. Eukaryot Cell 2003; 2:238-46. [PMID: 12684373 PMCID: PMC154840 DOI: 10.1128/ec.2.2.238-246.2003] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2002] [Accepted: 01/07/2003] [Indexed: 01/30/2023]
Abstract
In filamentous fungi, a programmed cell death (PCD) reaction occurs when cells of unlike genotype fuse. This reaction is caused by genetic differences at specific loci termed het loci (for heterokaryon incompatibility). Although several het genes have been characterized, the mechanism of this cell death reaction and its relation to PCD in higher eukaryotes remains largely unknown. In Podospora anserina, genes induced during the cell death reaction triggered by the het-R het-V interaction have been identified and termed idi genes. Herein, we describe the functional characterization of one idi gene (idi-1) and explore the connection between incompatibility and the response to nutrient starvation. We show that IDI-1 is a cell wall protein which localizes at the septum during normal growth. We found that induction of idi-1 and of the other known idi genes is not specific of the incompatibility reaction. The idi genes are induced upon nitrogen and carbon starvation and by rapamycin, a specific inhibitor of the TOR kinase pathway. The cytological hallmarks of het-R het-V incompatibility (increased septation, vacuolization, coalescence of lipid droplets, induction of autophagy, and cell death) are also observed during rapamycin treatment. Globally the cytological alterations and modifications in gene expression occurring during the incompatibility reaction are similar to those observed during starvation or rapamycin treatment.
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Affiliation(s)
- Karine Dementhon
- Laboratoire de Génétique Moléculaire des Champignons, Institut de Biochimie et de Génétique Cellulaires, UMR 5095 CNRS-Université de Bordeaux 2, Bordeaux, France
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Affiliation(s)
- Elizabeth W Jones
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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Bailleul PA, Newnam GP, Steenbergen JN, Chernoff YO. Genetic study of interactions between the cytoskeletal assembly protein sla1 and prion-forming domain of the release factor Sup35 (eRF3) in Saccharomyces cerevisiae. Genetics 1999; 153:81-94. [PMID: 10471702 PMCID: PMC1460745 DOI: 10.1093/genetics/153.1.81] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Striking similarities between cytoskeletal assembly and the "nucleated polymerization" model of prion propagation suggest that similar or overlapping sets of proteins may assist in both processes. We show that the C-terminal domain of the yeast cytoskeletal assembly protein Sla1 (Sla1C) specifically interacts with the N-terminal prion-forming domain (Sup35N) of the yeast release factor Sup35 (eRF3) in the two-hybrid system. Sla1C and several other Sup35N-interacting proteins also exhibit two-hybrid interactions with the poly-Gln-expanded N-proximal fragment of human huntingtin, which promotes Huntington disease-associated aggregation. The Sup35N-Sla1C interaction is inhibited by Sup35N alterations that make Sup35 unable to propagate the [PSI(+)] state and by the absence of the chaperone protein Hsp104, which is essential for [PSI] propagation. In a Sla1(-) background, [PSI] curing by dimethylsulfoxide or excess Hsp104 is increased, while translational readthrough and de novo [PSI] formation induced by excess Sup35 or Sup35N are decreased. These data show that, in agreement with the proposed function of Sla1 during cytoskeletal formation, Sla1 assists in [PSI] formation and propagation, but is not required for these processes. Sla1(-) strains are sensitive to some translational inhibitors, and some sup35 mutants, obtained in a Sla1(-) background, are sensitive to Sla1, suggesting that the interaction between Sla1 and Sup35 proteins may play a role in the normal function of the translational apparatus. We hypothesize that Sup35N is involved in regulatory interactions with intracellular structural networks, and [PSI] prion may be formed as a by-product of this process.
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Affiliation(s)
- P A Bailleul
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332-0230, USA
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14
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Abstract
In Saccharomyces cerevisiae the expression of all known nitrogen catabolite pathways are regulated by four regulators known as Gln3, Gat1, Dal80, and Deh1. This is known as nitrogen catabolite repression (NCR). They bind to motifs in the promoter region to the consensus sequence 5'GATAA 3'. Gln3 and Gat1 act positively on gene expression whereas Dal80 and Deh1 act negatively. Expression of nitrogen catabolite pathway genes known to be regulated by these four regulators are glutamine, glutamate, proline, urea, arginine. GABA, and allantonie. In addition, the expression of the genes encoding the general amino acid permease and the ammonium permease are also regulated by these four regulatory proteins. Another group of genes whose expression is also regulated by Gln3, Gat1, Dal80, and Deh1 are some proteases, CPS1, PRB1, LAP1, and PEP4, responsible for the degradation of proteins into amino acids thereby providing a nitrogen source to the cell. In this review, all known promoter sequences related to expression of nitrogen catabolite pathways are discussed as well as other regulatory proteins. Overview of metabolic pathways and promotors are presented.
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Affiliation(s)
- J Hofman-Bang
- Department of Biotechnology, Technical University of Denmark, Lyngby, Denmark.
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15
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Ouyang Q, Ruiz-Noriega M, Henry SA. The REG1 gene product is required for repression of INO1 and other inositol-sensitive upstream activating sequence-containing genes of yeast. Genetics 1999; 152:89-100. [PMID: 10224245 PMCID: PMC1460607 DOI: 10.1093/genetics/152.1.89] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A search was conducted for suppressors of the inositol auxotrophic phenotype of the ino4-8 mutant of yeast. The ino4-8 mutation is a single base pair change that results in substitution of lysine for glutamic acid at position 79 in the bHLH domain of the yeast regulatory protein, Ino4p. Ino4p dimerizes with a second bHLH protein, Ino2p, to form a complex that binds to the promoter of the INO1 gene, activating transcription. Of 31 recessive suppressors of ino4-8 isolated, 29 proved to be alleles of a single locus, identified as REG1, which encodes a regulatory subunit of a protein phosphatase involved in the glucose response pathway. The suppressor mutation, sia1-1, identified as an allele of REG1, caused constitutive INO1 expression and was capable of suppressing the inositol auxotrophy of a second ino4 missense mutant, ino4-26, as well as ino2-419, a missense mutation of INO2. The suppressors analyzed were unable to suppress ino2 and ino4 null mutations, but the reg1 deletion mutation could suppress ino4-8. A deletion mutation in the OPI1 negative regulator was incapable of suppressing ino4-8. The relative roles of the OPI1 and REG1 gene products in control of INO1 expression are discussed.
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Affiliation(s)
- Q Ouyang
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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Naik RR, Jones EW. The PBN1 gene of Saccharomyces cerevisiae: an essential gene that is required for the post-translational processing of the protease B precursor. Genetics 1998; 149:1277-92. [PMID: 9649520 PMCID: PMC1460229 DOI: 10.1093/genetics/149.3.1277] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The vacuolar hydrolase protease B in Saccharomyces cerevisiae is synthesized as an inactive precursor (Prb1p). The precursor undergoes post-translational modifications while transiting the secretory pathway. In addition to N- and O-linked glycosylations, four proteolytic cleavages occur during the maturation of Prb1p. Removal of the signal peptide by signal peptidase and the autocatalytic cleavage of the large amino-terminal propeptide occur in the endoplasmic reticulum (ER). Two carboxy-terminal cleavages of the post regions occur in the vacuole: the first cleavage is catalyzed by protease A and the second results from autocatalysis. We have isolated a mutant, pbn1-1, that exhibits a defect in the ER processing of Prb1p. The autocatalytic cleavage of the propeptide from Prb1p does not occur and Prb1p is rapidly degraded in the cytosol. PBN1 was cloned and is identical to YCL052c on chromosome III. PBN1 is an essential gene that encodes a novel protein. Pbn1p is predicted to contain a sub-C-terminal transmembrane domain but no signal sequence. A functional HA epitope-tagged Pbn1p fusion localizes to the ER. Pbn1p is N-glycosylated in its amino-terminal domain, indicating a lumenal orientation despite the lack of a signal sequence. Based on these results, we propose that one of the functions of Pbn1p is to aid in the autocatalytic processing of Prb1p.
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Affiliation(s)
- R R Naik
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
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Abstract
The expression of most nitrogen catabolic genes in Saccharomyces cerevisiae is regulated at the level of transcription in response to the quality of nitrogen source available. This regulation is accomplished through four GATA-family transcription factors: two positively acting factors capable of transcriptional activation (Gln3p and Gat1p) and two negatively acting factors capable of down-regulating Gln3p- and/or Gat1p-dependent transcription (Dal80p and Deh1p). Current understanding of nitrogen-responsive transcriptional regulation is the result of extensive analysis of genes required for the catabolism of small molecules, e.g., amino acids, allantoin, or ammonia. However, cells contain another, equally important source of nitrogen, intracellular protein, which undergoes rapid turnover during special circumstances such as entry into stationary phase, and during sporulation. Here we show that the expression of some (CPS1, PEP4, PRB1, and LAP4) but not all (PRC1) vacuolar protease genes is nitrogen catabolite repression sensitive and is regulated by the GATA-family proteins Gln3p, Gat1p, and Dal80p. These observations extend the global participation of GATA-family transcription factors to include not only well-studied genes associated with the catabolism of small nitrogenous compounds but also genes whose products are responsible for the turnover of intracellular macromolecules. They also point to the usefulness of considering control of the nitrogen-responsive GATA factors when studying the regulation of the protein turnover machinery.
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Affiliation(s)
- J A Coffman
- Department of Microbiology and Immunology, University of Tennessee, Memphis 38163, USA
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