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Chen Y, Wang W, Liu P, Lin A, Fan X, Wu C, Li N, Wei L, Wei D. The novel repressor Rce2 competes with Ace3 to regulate cellulase gene expression in the filamentous fungus Trichoderma reesei. Mol Microbiol 2021; 116:1298-1314. [PMID: 34608686 DOI: 10.1111/mmi.14825] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/22/2021] [Accepted: 09/27/2021] [Indexed: 11/29/2022]
Abstract
The filamentous fungus Trichoderma reesei is widely used for industrial cellulase production. In T. reesei, cellulase gene expression is tightly controlled by a regulatory network involving multiple transcription factors. Here, we isolated a novel protein, Rce2, using a pull-down assay and mass spectrometry analysis, from a partial carbon catabolite de-repression mutant, T. reesei Rut-C30, cultured under glucose-repressing conditions. Deletion and overexpression of Rce2 in T. reesei wild-type QM6a and mutant Rut-C30 revealed that Rce2 acts as a repressor of cellulase gene expression. DNase I footprinting assays, electrophoretic mobility shift assays, and chromatin immunoprecipitation assays revealed that Rce2 was located in the nucleus and bound to the consensus sequences 5'-(T/A)NNNNCCG-3' and 5'-CGGNNNN(T/A)-3' in the promoters of cellulase-related genes to repress their transcription. Additionally, Rce2 antagonized Ace3 binding to the cbh1 promoter to repress its transcription. However, Rce2 was not involved in Cre1-mediated carbon catabolite repression. These results demonstrate the mechanism through which Rce2 represses the expression of cellulase genes and provide novel insights into the regulatory system of cellulases and methods that can be used for the regulation of gene expression in T. reesei.
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Affiliation(s)
- Yumeng Chen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Wei Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Pei Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Aibo Lin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Xingjia Fan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Chuan Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Ni Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Liujing Wei
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Dongzhi Wei
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
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2
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The F-box protein gene exo- 1 is a target for reverse engineering enzyme hypersecretion in filamentous fungi. Proc Natl Acad Sci U S A 2021; 118:2025689118. [PMID: 34168079 DOI: 10.1073/pnas.2025689118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Carbohydrate active enzymes (CAZymes) are vital for the lignocellulose-based biorefinery. The development of hypersecreting fungal protein production hosts is therefore a major aim for both academia and industry. However, despite advances in our understanding of their regulation, the number of promising candidate genes for targeted strain engineering remains limited. Here, we resequenced the genome of the classical hypersecreting Neurospora crassa mutant exo-1 and identified the causative point of mutation to reside in the F-box protein-encoding gene, NCU09899. The corresponding deletion strain displayed amylase and invertase activities exceeding those of the carbon catabolite derepressed strain Δcre-1, while glucose repression was still mostly functional in Δexo-1 Surprisingly, RNA sequencing revealed that while plant cell wall degradation genes are broadly misexpressed in Δexo-1, only a small fraction of CAZyme genes and sugar transporters are up-regulated, indicating that EXO-1 affects specific regulatory factors. Aiming to elucidate the underlying mechanism of enzyme hypersecretion, we found the high secretion of amylases and invertase in Δexo-1 to be completely dependent on the transcriptional regulator COL-26. Furthermore, misregulation of COL-26, CRE-1, and cellular carbon and nitrogen metabolism was confirmed by proteomics. Finally, we successfully transferred the hypersecretion trait of the exo-1 disruption by reverse engineering into the industrially deployed fungus Myceliophthora thermophila using CRISPR-Cas9. Our identification of an important F-box protein demonstrates the strength of classical mutants combined with next-generation sequencing to uncover unanticipated candidates for engineering. These data contribute to a more complete understanding of CAZyme regulation and will facilitate targeted engineering of hypersecretion in further organisms of interest.
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Laussel C, Léon S. Cellular toxicity of the metabolic inhibitor 2-deoxyglucose and associated resistance mechanisms. Biochem Pharmacol 2020; 182:114213. [PMID: 32890467 DOI: 10.1016/j.bcp.2020.114213] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/28/2020] [Accepted: 08/31/2020] [Indexed: 12/31/2022]
Abstract
Most malignant cells display increased glucose absorption and metabolism compared to surrounding tissues. This well-described phenomenon results from a metabolic reprogramming occurring during transformation, that provides the building blocks and supports the high energetic cost of proliferation by increasing glycolysis. These features led to the idea that drugs targeting glycolysis might prove efficient in the context of cancer treatment. One of these drugs, 2-deoxyglucose (2-DG), is a synthetic glucose analog that can be imported into cells and interfere with glycolysis and ATP generation. Its preferential targeting to sites of cell proliferation is supported by the observation that a derived molecule, 2-fluoro-2-deoxyglucose (FDG) accumulates in tumors and is used for cancer imaging. Here, we review the toxicity mechanisms of this drug, from the early-described effects on glycolysis to its other cellular consequences, including inhibition of protein glycosylation and endoplasmic reticulum stress, and its interference with signaling pathways. Then, we summarize the current data on the use of 2-DG as an anti-cancer agent, especially in the context of combination therapies, as novel 2-DG-derived drugs are being developed. We also show how the use of 2-DG helped to decipher glucose-signaling pathways in yeast and favored their engineering for biotechnologies. Finally, we discuss the resistance strategies to this inhibitor that have been identified in the course of these studies and which may have important implications regarding a medical use of this drug.
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Affiliation(s)
- Clotilde Laussel
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France
| | - Sébastien Léon
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France.
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Horta MAC, Thieme N, Gao Y, Burnum-Johnson KE, Nicora CD, Gritsenko MA, Lipton MS, Mohanraj K, de Assis LJ, Lin L, Tian C, Braus GH, Borkovich KA, Schmoll M, Larrondo LF, Samal A, Goldman GH, Benz JP. Broad Substrate-Specific Phosphorylation Events Are Associated With the Initial Stage of Plant Cell Wall Recognition in Neurospora crassa. Front Microbiol 2019; 10:2317. [PMID: 31736884 PMCID: PMC6838226 DOI: 10.3389/fmicb.2019.02317] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/23/2019] [Indexed: 12/26/2022] Open
Abstract
Fungal plant cell wall degradation processes are governed by complex regulatory mechanisms, allowing the organisms to adapt their metabolic program with high specificity to the available substrates. While the uptake of representative plant cell wall mono- and disaccharides is known to induce specific transcriptional and translational responses, the processes related to early signal reception and transduction remain largely unknown. A fast and reversible way of signal transmission are post-translational protein modifications, such as phosphorylations, which could initiate rapid adaptations of the fungal metabolism to a new condition. To elucidate how changes in the initial substrate recognition phase of Neurospora crassa affect the global phosphorylation pattern, phospho-proteomics was performed after a short (2 min) induction period with several plant cell wall-related mono- and disaccharides. The MS/MS-based peptide analysis revealed large-scale substrate-specific protein phosphorylation and de-phosphorylations. Using the proteins identified by MS/MS, a protein-protein-interaction (PPI) network was constructed. The variance in phosphorylation of a large number of kinases, phosphatases and transcription factors indicate the participation of many known signaling pathways, including circadian responses, two-component regulatory systems, MAP kinases as well as the cAMP-dependent and heterotrimeric G-protein pathways. Adenylate cyclase, a key component of the cAMP pathway, was identified as a potential hub for carbon source-specific differential protein interactions. In addition, four phosphorylated F-Box proteins were identified, two of which, Fbx-19 and Fbx-22, were found to be involved in carbon catabolite repression responses. Overall, these results provide unprecedented and detailed insights into a so far less well known stage of the fungal response to environmental cues and allow to better elucidate the molecular mechanisms of sensory perception and signal transduction during plant cell wall degradation.
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Affiliation(s)
- Maria Augusta C. Horta
- Holzforschung München, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Nils Thieme
- Holzforschung München, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Yuqian Gao
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | | | - Carrie D. Nicora
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Marina A. Gritsenko
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Mary S. Lipton
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Karthikeyan Mohanraj
- The Institute of Mathematical Sciences (IMSc), Homi Bhabha National Institute (HBNI), Chennai, India
| | - Leandro José de Assis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Liangcai Lin
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Chaoguang Tian
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Gerhard H. Braus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Katherine A. Borkovich
- Department of Microbiology & Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Monika Schmoll
- AIT - Austrian Institute of Technology GmbH, Center for Health & Bioresources, Tulln, Austria
| | - Luis F. Larrondo
- Millennium Institute for Integrative Biology (iBio), Departamento Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Areejit Samal
- The Institute of Mathematical Sciences (IMSc), Homi Bhabha National Institute (HBNI), Chennai, India
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- Institute for Advanced Study, Technical University of Munich, Garching, Germany
| | - J. Philipp Benz
- Holzforschung München, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
- Institute for Advanced Study, Technical University of Munich, Garching, Germany
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Cao Y, Zheng F, Wang L, Zhao G, Chen G, Zhang W, Liu W. Rce1, a novel transcriptional repressor, regulates cellulase gene expression by antagonizing the transactivator Xyr1 in Trichoderma reesei. Mol Microbiol 2017; 105:65-83. [PMID: 28378498 DOI: 10.1111/mmi.13685] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2017] [Indexed: 11/28/2022]
Abstract
Cellulase gene expression in the model cellulolytic fungus Trichoderma reesei is supposed to be controlled by an intricate regulatory network involving multiple transcription factors. Here, we identified a novel transcriptional repressor of cellulase gene expression, Rce1. Disruption of the rce1 gene not only facilitated the induced expression of cellulase genes but also led to a significant delay in terminating the induction process. However, Rce1 did not participate in Cre1-mediated catabolite repression. Electrophoretic mobility shift (EMSA) and DNase I footprinting assays in combination with chromatin immunoprecipitation (ChIP) demonstrated that Rce1 could bind directly to a cbh1 (cellobiohydrolase 1-encoding) gene promoter region containing a cluster of Xyr1 binding sites. Furthermore, competitive binding assays revealed that Rce1 antagonized Xyr1 from binding to the cbh1 promoter. These results indicate that intricate interactions exist between a variety of transcription factors to ensure tight and energy-efficient regulation of cellulase gene expression in T. reesei. This study also provides important clues regarding increased cellulase production in T. reesei.
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Affiliation(s)
- Yanli Cao
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No. 27 Shanda South Road, Jinan, Shandong, 250100, P. R. China
| | - Fanglin Zheng
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No. 27 Shanda South Road, Jinan, Shandong, 250100, P. R. China
| | - Lei Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No. 27 Shanda South Road, Jinan, Shandong, 250100, P. R. China
| | - Guolei Zhao
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No. 27 Shanda South Road, Jinan, Shandong, 250100, P. R. China
| | - Guanjun Chen
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No. 27 Shanda South Road, Jinan, Shandong, 250100, P. R. China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No. 27 Shanda South Road, Jinan, Shandong, 250100, P. R. China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No. 27 Shanda South Road, Jinan, Shandong, 250100, P. R. China
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6
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Lima JO, Pereira JF, Araújo EFD, Queiroz MVD. Pectin lyase overproduction by Penicillium griseoroseum mutants resistant to catabolite repression. Braz J Microbiol 2017; 48:602-606. [PMID: 28237679 PMCID: PMC5498439 DOI: 10.1016/j.bjm.2016.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 12/09/2016] [Accepted: 12/26/2016] [Indexed: 12/30/2022] Open
Abstract
Expression of pectinolytic genes is regulated by catabolic repression limiting the production of pectin lyase (PL) if the natural inducer, pectin, is missing from the growth medium. Here, we report the isolation of Penicillium griseoroseum mutants resistant to 2-deoxy-d-glucose (DG) that show resistance to catabolite repression and overproduce PL. Three spontaneous and nine UV-induced mutants were obtained. Some mutants produced sectors (segments morphologically different) that were also studied. The mutants were analyzed for pectinases production on pectinase-agar plates and five mutants and two sectors showing larger clearing zones than the wild type were selected for quantitative assay. Although PL production higher than the wild type has been found, phenotype instability was observed for most of the mutants and, after transfers to nonselective medium, the DG resistance was no longer present. Only mutants M03 and M04 were stable maintaining the DG-resistance phenotype. When growing for 120 h in liquid medium containing glucose with or without pectin, both mutants showed higher PL production. In the presence of glucose as sole carbon source, the mutant M03 produced 7.8-fold more PL than the wild type. Due its phenotypic stability and PL overproduction, the mutant M03 presents potential for industrial applications.
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Affiliation(s)
| | - Jorge Fernando Pereira
- Universidade Federal de Viçosa, Departamento de Microbiologia, Viçosa, MG, Brazil; Embrapa Trigo, Passo Fundo, RS, Brazil
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Wang B, Li J, Gao J, Cai P, Han X, Tian C. Identification and characterization of the glucose dual-affinity transport system in Neurospora crassa: pleiotropic roles in nutrient transport, signaling, and carbon catabolite repression. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:17. [PMID: 28115989 PMCID: PMC5244594 DOI: 10.1186/s13068-017-0705-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 01/07/2017] [Indexed: 05/07/2023]
Abstract
BACKGROUND The glucose dual-affinity transport system (low- and high-affinity) is a conserved strategy used by microorganisms to cope with natural fluctuations in nutrient availability in the environment. The glucose-sensing and uptake processes are believed to be tightly associated with cellulase expression regulation in cellulolytic fungi. However, both the identities and functions of the major molecular components of this evolutionarily conserved system in filamentous fungi remain elusive. Here, we systematically identified and characterized the components of the glucose dual-affinity transport system in the model fungus Neurospora crassa. RESULTS Using RNA sequencing coupled with functional transport analyses, we assigned GLT-1 (Km = 18.42 ± 3.38 mM) and HGT-1/-2 (Km = 16.13 ± 0.95 and 98.97 ± 22.02 µM) to the low- and high-affinity glucose transport systems, respectively. The high-affinity transporters hgt-1/-2 complemented a moderate growth defect under high glucose when glt-1 was deleted. Simultaneous deletion of hgt-1/-2 led to extensive derepression of genes for plant cell wall deconstruction in cells grown on cellulose. The suppression by HGT-1/-2 was connected to both carbon catabolite repression (CCR) and the cyclic adenosine monophosphate-protein kinase A pathway. Alteration of a residue conserved across taxa in hexose transporters resulted in a loss of glucose-transporting function, whereas CCR signal transduction was retained, indicating dual functions for HGT-1/-2 as "transceptors." CONCLUSIONS In this study, GLT-1 and HGT-1/-2 were identified as the key components of the glucose dual-affinity transport system, which plays diverse roles in glucose transport and carbon metabolism. Given the wide conservation of the glucose dual-affinity transport system across fungal species, the identification of its components and their pleiotropic roles in this study shed important new light on the molecular basis of nutrient transport, signaling, and plant cell wall degradation in fungi.
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Affiliation(s)
- Bang Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027 China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Jingfang Gao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- School of Life Sciences, Heilongjiang University, Harbin, 150080 Heilongjiang China
| | - Pengli Cai
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Xiaoyun Han
- School of Life Sciences, Heilongjiang University, Harbin, 150080 Heilongjiang China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
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Xiong Y, Sun J, Glass NL. VIB1, a link between glucose signaling and carbon catabolite repression, is essential for plant cell wall degradation by Neurospora crassa. PLoS Genet 2014; 10:e1004500. [PMID: 25144221 PMCID: PMC4140635 DOI: 10.1371/journal.pgen.1004500] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Accepted: 05/27/2014] [Indexed: 11/18/2022] Open
Abstract
Filamentous fungi that thrive on plant biomass are the major producers of hydrolytic enzymes used to decompose lignocellulose for biofuel production. Although induction of cellulases is regulated at the transcriptional level, how filamentous fungi sense and signal carbon-limited conditions to coordinate cell metabolism and regulate cellulolytic enzyme production is not well characterized. By screening a transcription factor deletion set in the filamentous fungus Neurospora crassa for mutants unable to grow on cellulosic materials, we identified a role for the transcription factor, VIB1, as essential for cellulose utilization. VIB1 does not directly regulate hydrolytic enzyme gene expression or function in cellulosic inducer signaling/processing, but affects the expression level of an essential regulator of hydrolytic enzyme genes, CLR2. Transcriptional profiling of a Δvib-1 mutant suggests that it has an improper expression of genes functioning in metabolism and energy and a deregulation of carbon catabolite repression (CCR). By characterizing new genes, we demonstrate that the transcription factor, COL26, is critical for intracellular glucose sensing/metabolism and plays a role in CCR by negatively regulating cre-1 expression. Deletion of the major player in CCR, cre-1, or a deletion of col-26, did not rescue the growth of Δvib-1 on cellulose. However, the synergistic effect of the Δcre-1; Δcol-26 mutations circumvented the requirement of VIB1 for cellulase gene expression, enzyme secretion and cellulose deconstruction. Our findings support a function of VIB1 in repressing both glucose signaling and CCR under carbon-limited conditions, thus enabling a proper cellular response for plant biomass deconstruction and utilization.
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Affiliation(s)
- Yi Xiong
- Plant and Microbial Biology Department and The Energy Biosciences Institute, The University of California, Berkeley, Berkeley, California, United States of America
| | - Jianping Sun
- Plant and Microbial Biology Department and The Energy Biosciences Institute, The University of California, Berkeley, Berkeley, California, United States of America
| | - N. Louise Glass
- Plant and Microbial Biology Department and The Energy Biosciences Institute, The University of California, Berkeley, Berkeley, California, United States of America
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9
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D'Amore T. CAMBRIDGE PRIZE LECTURE IMPROVING YEAST FERMENTATION PERFORMANCE. JOURNAL OF THE INSTITUTE OF BREWING 2013. [DOI: 10.1002/j.2050-0416.1992.tb01119.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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10
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Montesinos-Matías R, Viniegra-González G, Alatorre-Rosas R, Loera O. Relationship between virulence and enzymatic profiles in the cuticle of Tenebrio molitor by 2-deoxy-d-glucose-resistant mutants of Beauveria bassiana (Bals.) Vuill. World J Microbiol Biotechnol 2011. [DOI: 10.1007/s11274-011-0672-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Robledo-Monterrubio M, Alatorre-Rosas R, Viniegra-González G, Loera O. Selection of improved Beauveria bassiana (Bals.) Vuill. strains based on 2-deoxy-d-glucose resistance and physiological analysis. J Invertebr Pathol 2009; 101:222-7. [DOI: 10.1016/j.jip.2009.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 05/05/2009] [Accepted: 05/14/2009] [Indexed: 11/25/2022]
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12
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Rajoka MI, Awan MS, Saleem M, Ayub N. Solid-state fermentation-supported enhanced production of α-galactosidase by a deoxyglucose-resistant mutant of Aspergillus niger and thermostabilization of the production process. World J Microbiol Biotechnol 2008. [DOI: 10.1007/s11274-008-9886-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Ziv C, Gorovits R, Yarden O. Carbon source affects PKA-dependent polarity of Neurospora crassa in a CRE-1-dependent and independent manner. Fungal Genet Biol 2008; 45:103-16. [PMID: 17625933 DOI: 10.1016/j.fgb.2007.05.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 05/07/2007] [Accepted: 05/22/2007] [Indexed: 11/21/2022]
Abstract
A defect in mcb, encoding the cAMP-dependent protein kinase A (PKA) regulatory subunit in Neurospora crassa, which confers an apolar growth phenotype, is accompanied by an increase in PKA activity levels. Both PKA and CRE-1 [a key carbon catabolite repression (CCR) regulator] mediate the cellular response to carbon-source availability. Inactivation of the cre-1 gene resulted in reduced growth rate, abnormal hyphal morphology and altered CCR. Both PKA and CRE-1 affected morphology in a carbon-dependent manner, as fructose suppressed the apolar morphology of the mcb strain and enabled faster growth of the Deltacre-1 mutant. An increase in cre-1 transcript abundance was observed in mcb and a reduction in PKA activity levels was measured in Deltacre-1. CRE-1 is involved in determining PKA-dependent polarity, as an mcb;Deltacre-1 strain displayed partial reestablishment of hyphal polarity. Taken together, our results demonstrate regulatory interactions between PKA and CRE-1 that affect cell polarity in a filamentous fungus.
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Affiliation(s)
- Carmit Ziv
- Department of Plant Pathology and Microbiology, The Otto Warburg Minerva Center for Agricultural Biotechnology, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel
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14
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Pectinase production by a diploid construct from two Aspergillus niger overproducing mutants. Enzyme Microb Technol 1999. [DOI: 10.1016/s0141-0229(99)00015-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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15
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Nehls U, Ecke M, Hampp R. Sugar- and nitrogen-dependent regulation of an Amanita muscaria phenylalanine ammonium lyase gene. J Bacteriol 1999; 181:1931-3. [PMID: 10074091 PMCID: PMC93597 DOI: 10.1128/jb.181.6.1931-1933.1999] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/1998] [Accepted: 01/12/1999] [Indexed: 11/20/2022] Open
Abstract
The cDNA of a key enzyme of secondary metabolism, phenylalanine ammonium lyase, was identified for an ectomycorrhizal fungus by differential screening of a mycorrhizal library. The gene was highly expressed in hyphae grown at low external monosaccharide concentrations, but its expression was 30-fold reduced at elevated concentrations. Gene repression was regulated by hexokinase.
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Affiliation(s)
- U Nehls
- Universität Tübingen, Botanisches Institut, Physiologische Okologie der Pflanzen, 72076 Tübingen, Germany.
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16
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Ebbole DJ. Carbon catabolite repression of gene expression and conidiation in Neurospora crassa. Fungal Genet Biol 1998; 25:15-21. [PMID: 9806802 DOI: 10.1006/fgbi.1998.1088] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- D J Ebbole
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, 77843-2132, USA.
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17
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Nehls U, Wiese J, Guttenberger M, Hampp R. Carbon allocation in ectomycorrhizas: identification and expression analysis of an Amanita muscaria monosaccharide transporter. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 1998; 11:167-76. [PMID: 9487692 DOI: 10.1094/mpmi.1998.11.3.167] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Ectomycorrhizas are formed between certain soil fungi and fine roots of predominantly woody plants. An important feature of this symbiosis is the supply of plant-derived carbohydrates to the fungus. As a first step toward a better understanding of the molecular basis of this process, we cloned a monosaccharide transporter from the ectomycorrhizal fungus Amanita muscaria. Degenerate oligonucleotide primers were designed to match conserved regions from known fungal sugar transporters. A cDNA fragment of the transporter was obtained from mycorrhizal mRNA by reverse transcription-polymerase chain reaction. This fragment was used to identify a clone (AmMst1) encoding the entire monosaccharide transporter in a Picea abies/A. muscaria mycorrhizal cDNA library. The cDNA codes for an open reading frame of 520 amino acids, showing best homology to a Neurospora crassa monosaccharide transporter. The function of AmMST1 as monosaccharide transporter was confirmed by heterologous expression of the cDNA in a Schizosaccharomyces pombe mutant lacking a monosaccharide uptake system. AmMst1 was constitutively expressed in fungal hyphae under all growth conditions. Nevertheless, in mycorrhizas as well as in hyphae grown at monosaccharide concentrations above 5 mM, the amount of AmMst1 transcript increased fourfold. We therefore suggest that AmMst1 is upregulated in ectomycorrhizas by a monosaccharide-controlled mechanism.
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Affiliation(s)
- U Nehls
- Universität Tübingen, Germany.
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18
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Parvez S, Rajoka MI, Ahmed MN, Latif F, Shahid R, Malik KA. Citric acid production from sugar cane molasses by 2-deoxyglucose-resistant mutant strain ofAspergillus niger. Folia Microbiol (Praha) 1998. [DOI: 10.1007/bf02815544] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Physiological comparison between pectinase-producing mutants of Aspergillus niger adapted either to solid-state fermentation or submerged fermentation. Enzyme Microb Technol 1997. [DOI: 10.1016/s0141-0229(96)00212-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Madi L, McBride SA, Bailey LA, Ebbole DJ. rco-3, a gene involved in glucose transport and conidiation in Neurospora crassa. Genetics 1997; 146:499-508. [PMID: 9178001 PMCID: PMC1207992 DOI: 10.1093/genetics/146.2.499] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Macroconidiation in Neurospora crassa is influenced by a number of environmental cues, including the nutritional status of the growing organism. Conidia formation is normally observed when the fungus is exposed to air. However, carbon limitation can induce conidiation in mycclia submerged in an aerated liquid medium. A mutant was previously isolated that could conidiate in submerged culture without imposing nutrient limitation and the gene responsible for this phenotype (rco-3) has now been cloned. RCO3 exhibits sequence similarity to members of the sugar transporter gene superfamily, with greatest similarity to glucose transporters of yeast. Consistent with this structural similarity, we find that glucose transport activity is altered in the mutant. However, growth of the mutant in media containing alternate carbon sources does not suppress conidiation in submerged culture. The properties of the mutant suggest that RCO3 is required for expression of glucose transport activity, glucose regulation of gene expression, and general carbon repression of development.
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Affiliation(s)
- L Madi
- Department of Plant Pathology and Microbiology, Texas A & M University, College Station 77843, USA
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21
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Detection of highly productive strains of Pleurotus ostreatus by their tolerance to 2-deoxy-D-glucose in starch-based media. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0953-7562(96)80143-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Torres NV, Riol-Cimas JM, Wolschek M, Kubicek CP. Glucose transport byAspergillus niger: the low-affinity carrier is only formed during growth on high glucose concentrations. Appl Microbiol Biotechnol 1996. [DOI: 10.1007/bf00178620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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23
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Janisiewicz WJ. Enhancement of Biocontrol of Blue Mold with the Nutrient Analog 2-Deoxy-
d
-Glucose on Apples and Pears. Appl Environ Microbiol 1994; 60:2671-6. [PMID: 16349342 PMCID: PMC201707 DOI: 10.1128/aem.60.8.2671-2676.1994] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The glucose analog, 2-deoxy-
d
-glucose (2-DOG) enhanced biocontrol of blue mold (caused by
Penicillium expansum
), the most important postharvest disease of apples and pears. 2-DOG strongly inhibited
P. expansum
, and of the two antagonists investigated,
Pseudomonas syringae
was resistant to 2-DOG at 10 mg/ml whereas
Sporobolomyces roseus
was susceptible. A mutant of
S. roseus
resistant to 2-DOG was developed. Addition of 2-DOG at 4 mg/ml allowed more than a 10-fold reduction in the concentration of the antagonists applied to fruits without diminishing control. This effect was still apparent at an inoculum of 5 × 10
4
conidia of
P. expansum
per ml, which greatly exceeds concentrations found under normal commercial conditions. The effect of 2-DOG on biocontrol was stronger on apples than on pears. 2-DOG had no effect on populations of the antagonists, which increased greatly in wounds on apples and pears. The reduction in the concentration of the antagonists needed for control may improve the reliability and economy of the biocontrol system and may have a significant impact on commercialization of this new technology.
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Affiliation(s)
- W J Janisiewicz
- Appalachian Fruit Research Station, USDA Agricultural Research Service, Kearneysville, West Virginia 25430
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24
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Steinböck F, Choojun S, Held I, Roehr M, Kubicek CP. Characterization and regulatory properties of a single hexokinase from the citric acid accumulating fungus Aspergillus niger. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1200:215-23. [PMID: 8031843 DOI: 10.1016/0304-4165(94)90138-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A single glucose-phosphorylating enzyme has been detected and purified from the citric acid accumulating fungus Aspergillus niger. The enzyme was formed constitutively, and high activities were formed on glucose and sucrose as carbon sources. Highest activities were formed during growth on high concentrations of glucose or sucrose. The enzyme, purified about 600-fold from cell-free extracts prepared from glucose-grown mycelia, gave a double band in denaturing (SDS)-polyacrylamide gel electrophoresis. Tryptic peptide patterns suggest that the lower molecular weight band was the product of either C- or N-terminal truncation. The specific activity of the enzyme was about 40 and 35 mumol/min and mg protein with glucose and fructose as substrates, respectively. The affinity for glucose was about 10(3)-fold higher than for fructose. The subunit molecular weight was 50,000 and the molecular weight of the native protein was 100,000 by gel permeation chromatography. Of the reaction products ADP, but not glucose 6-phosphate, inhibited hexokinase activity. Citrate inhibited (K1 0.15 mM) non-competitively with respect to both glucose and ATP, which was not due to Mg(2+)-chelation. 2-Deoxyglucose resistant mutant strains of A. niger were isolated which showed decreased growth rate and activity of hexokinase during growth on glucose, while their growth on fructose and hexokinase activities were comparable to the parent strain. They displayed a reduced rate of citric acid accumulation. It is concluded that the synthesis of very high hexokinase activities may counteract citrate inhibition, thereby guaranteeing a high glycolytic flux during citric acid accumulation.
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Affiliation(s)
- F Steinböck
- Institut für Biochemische Technologie und Mikrobiologie, TU Wien, Vienna, Austria
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25
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Tata M, Menawat AS. Cyclic AMP regulation of tylosin biosynthesis and secondary metabolism inStreptomyces fradiae. Biotechnol Bioeng 1994; 44:283-90. [DOI: 10.1002/bit.260440305] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Bodie EA, Armstrong GL, Dunn-Coleman NS. Strain improvement of chymosin-producing strains of Aspergillus niger var. awamori using parasexual recombination. Enzyme Microb Technol 1994; 16:376-82. [PMID: 7764791 DOI: 10.1016/0141-0229(94)90151-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Parasexual recombination was used to obtain improved chymosin-producing strains and to perform genetic analysis on existing strains. Chlorate resistance was used to select for a variety of spontaneous nitrate assimilation pathway mutations in strains previously improved for chymosin production using classical strain improvement methods including mutation and screening, and selection for 2-deoxyglucose resistance (dgr). Diploids of these improved strains were generated via parasexual recombination and were isolated on selective media by complementation of nitrate assimilation mutations. A preliminary genetic analysis of diploid and haploid segregants indicated that the dgr trait, resulting in overexpression of chymosin, was recessive. Also, mutations in two different dgr genes resulted in an increased level of chymosin production. When these mutations were combined via parasexual recombination, the resulting haploid segregants produced about 15% more chymosin than either parental strain. CHEF gel electrophoresis was used to determine the chromosomal location of the integrated chymosin DNA sequences, and to verify diploidy in one case where the chromosome composition of two haploid parents differed.
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Affiliation(s)
- E A Bodie
- Genencor International, South San Francisco, CA 94080
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27
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D'Amore T, Dowhanick TM. Biochemical and Genetic Characterization of a 2-Deoxy-D-Glucose Resistant Mutant of Saccharomyces Cerevisiae. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 1994. [DOI: 10.1094/asbcj-52-0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Tony D'Amore
- Brewing Research Department, Labatt Breweries of Canada, 150 Simcoe Street, London, Ontario, Canada N6A 4M3
| | - Terrance M. Dowhanick
- Brewing Research Department, Labatt Breweries of Canada, 150 Simcoe Street, London, Ontario, Canada N6A 4M3
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28
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Pectinase-hyperproducing mutants of Aspergillus niger C28B25 for solid-state fermentation of coffee pulp. Enzyme Microb Technol 1993. [DOI: 10.1016/0141-0229(93)90146-s] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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29
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Kubicek CP, Messner R, Gruber F, Mach RL, Kubicek-Pranz EM. The Trichoderma cellulase regulatory puzzle: from the interior life of a secretory fungus. Enzyme Microb Technol 1993; 15:90-99. [PMID: 7763457 DOI: 10.1016/0141-0229(93)90030-6] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Novel applications for cellulases have reinitiated interest in the regulation of production of these enzymes by the soft rot fungus Trichoderma reesei and related species. This paper reviews the current state of knowledge concerning the question "How can insoluble molecules like cellulose initiate their own breakdown by a microorganism?" The evidence available--based on biochemical as well as molecular biological approaches--favors a model in which conidial bound cellobiohydrolases carry out a first exo-exo-wise attack on the cellulose molecule. The disaccharides so formed (cellobiose, alpha-cellobiono-1,5-lactone) are then taken up by the mycelia and promote further cellulase biosynthesis. Evidence available suggests that they are further metabolized to, rather than being, the "true" inducer. Speculations on the nature of the inducer are presented. The roles of the beta-glucosidases of Trichoderma in this process are discussed. The pathway of cellulase secretion is discussed on the basis of electron microscopical as well as gene sequence information.
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Affiliation(s)
- C P Kubicek
- Abteilung für Mikrobielle Biochemie, Institut für Biochemische Technologie und Mikrobiologie, Vienna, Austria
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30
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Antier P, Minjares A, Roussos S, Viniegra-González G. New approach for selecting pectinase producing mutants of Aspergillus niger well adapted to solid state fermentation. Biotechnol Adv 1993; 11:429-40. [PMID: 14545667 DOI: 10.1016/0734-9750(93)90012-c] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aim of this paper is to review and study a new approach for improving strains of Aspergillus niger specially adapted to produce pectinases by Solid State Fermentation (SSF) with materials having low levels of water activity (a(w)), i.e., coffee pulp. Special emphasis is placed on the use of two antimetabolic compounds: 2-deoxy-glucose (DG) and 2,4-dinitro-phenol (DNP) combined with a water depressant (ethylene glycol = EG) in order to put strong selection pressures on UV treated spores from parental strain C28B25 isolated from a coffee plantation. Such a strain was found to be DG sensitive. Results suggested the existence of a reciprocal relation between adaptation of isolated strains to SSF or to Submerged Fermentation (SmF) systems. Preliminary physiological analysis of isolated strains showed that at least some few initially DG resistant mutants could revert to DG sensitive phenotype but conserving increased pectinase production. Also it was found that phenotype for DNP resistance could be associated to changes of DG resistance. Finally, it was found that low levels of a(w) produced by adding 15% EG to agar plates, were a significant selection factor for strains well adapted to SSF system.
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Affiliation(s)
- P Antier
- Institute Français de Récherche Scientifique pour le Dévéloppement en Cooperation (ORSTOM), Cirerón 609, Colonia Los Morales, DF, México
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31
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Abstract
The extraordinary capacity of filamentous fungi to produce large quantities of extracellular protein, together with the advent of DNA-mediated fungal transformation, has resulted in rapid advances in the development of gene expression systems for filamentous fungi. This review focuses on recent developments in the expression of both fungal and non-fungal genes and improvements to the host.
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Affiliation(s)
- T Fowler
- Genencor International Inc., South San Francisco, California
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32
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Dunn-Coleman NS, Bloebaum P, Berka RM, Bodie E, Robinson N, Armstrong G, Ward M, Przetak M, Carter GL, LaCost R. Commercial Levels of Chymosin Production by Aspergillus. ACTA ACUST UNITED AC 1991; 9:976-81. [PMID: 1368725 DOI: 10.1038/nbt1091-976] [Citation(s) in RCA: 125] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have increased the production of bovine chymosin in Aspergillus niger var. awamori to more than one gram per liter of secreted authentic enzyme by combining a mutagenesis protocol with a novel robotic screening program. Analysis of the superior chymosin producing strains indicated that they have enhanced capabilities to secrete extracellular proteins.
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33
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Hexose-phosphorylating enzyme activities and carbon catabolite control of cellulase formation in Trichoderma reesei QM 9414 and some partially constitutive cellulase producer strains. Enzyme Microb Technol 1991. [DOI: 10.1016/0141-0229(91)90186-e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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34
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Sugar uptake in a 2-deoxy-d-glucose resistant mutant ofSaccharomyces cerevisiae. ACTA ACUST UNITED AC 1991. [DOI: 10.1007/bf01575600] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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35
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Butler DK, Metzenberg RL. Expansion and contraction of the nucleolus organizer region of Neurospora: changes originate in both proximal and distal segments. Genetics 1990; 126:325-33. [PMID: 2147160 PMCID: PMC1204187 DOI: 10.1093/genetics/126.2.325] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Previously we have shown that the nucleolus organizer region (NOR) of Neurospora crassa changes size frequently during the premeiotic portion of the sexual phase. Here, we have investigated whether these changes in size originate only in specific regions of the NOR, or are distributed throughout the NOR. In two special strains of Neurospora, the NOR was divided into proximal and distal segments. In the first, the NOR was divided by a translocation breakpoint and, in the second, the NOR was divided by a meiotic crossover point. The two strains were crossed individually to normal sequence tester strains and the sizes of the proximal and distal segments were followed by pulsed-field gel electrophoresis. The analysis of progeny from both crosses indicates that the events affecting NOR size are not limited to a specific region of the NOR. Additionally, we have obtained evidence that the rDNA of N. crassa can undergo unequal sister chromatid exchange.
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Affiliation(s)
- D K Butler
- Department of Physiological Chemistry, University of Wisconsin, Madison 53706
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36
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Characterization of sugar transport in 2-deoxy-d-glucose resistant mutants of yeast. ACTA ACUST UNITED AC 1990. [DOI: 10.1007/bf01576435] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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37
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Novak S, D'Amore T, Stewart GG. 2-Deoxy-D-glucose resistant yeast with altered sugar transport activity. FEBS Lett 1990; 269:202-4. [PMID: 2201568 DOI: 10.1016/0014-5793(90)81154-g] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The transport of glucose and maltose in Saccharomyces cerevisiae was observed to occur by both high and low affinity transport systems. A spontaneously isolated 2-deoxy-D-glucose resistant mutant was observed to transport glucose and maltose only by the high affinity transport systems. Associated with this was an increase in the Vmax values, indicating derepression of the high affinity transport systems. The low affinity transport systems could not be detected. This mutant will be important in examining the repression regulatory and sugar transport mechanisms in yeast.
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Affiliation(s)
- S Novak
- Brewing Research Department, John Labatt Limited, London, Ont., Canada
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