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Kramer A, Beck HC, Kumar A, Kristensen LP, Imhoff JF, Labes A. Proteomic Analysis of Anti-Cancerous Scopularide Production by a Marine Microascus brevicaulis Strain and Its UV Mutant. PLoS One 2015; 10:e0140047. [PMID: 26460745 PMCID: PMC4603891 DOI: 10.1371/journal.pone.0140047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 09/21/2015] [Indexed: 11/19/2022] Open
Abstract
The marine fungus Microascus brevicaulis strain LF580 is a non-model secondary metabolite producer with high yields of the two secondary metabolites scopularides A and B, which exhibit distinct activities against tumour cell lines. A mutant strain was obtained using UV mutagenesis, showing faster growth and differences in pellet formation besides higher production levels. Here, we show the first proteome study of a marine fungus. Comparative proteomics were applied to gain deeper understanding of the regulation of production and of the physiology of the wild type strain and its mutant. For this purpose, an optimised protein extraction protocol was established. In total, 4759 proteins were identified. The central metabolic pathway of strain LF580 was mapped using the KEGG pathway analysis and GO annotation. Employing iTRAQ labelling, 318 proteins were shown to be significantly regulated in the mutant strain: 189 were down- and 129 upregulated. Proteomics are a powerful tool for the understanding of regulatory aspects: The differences on proteome level could be attributed to limited nutrient availability in the wild type strain due to a strong pellet formation. This information can be applied for optimisation on strain and process level. The linkage between nutrient limitation and pellet formation in the non-model fungus M. brevicaulis is in consensus with the knowledge on model organisms like Aspergillus niger and Penicillium chrysogenum.
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Affiliation(s)
- Annemarie Kramer
- Research Unit Marine Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Hans Christian Beck
- Centre for Clinical Proteomics, Department for Clinical Biochemistry and Pharmacology, Odense University Hospital, Odense, Denmark
| | - Abhishek Kumar
- Department for Botany and Molecular Biology, Institute of Botany, Christian-Albrechts University of Kiel, Kiel, Germany
| | - Lars Peter Kristensen
- Centre for Clinical Proteomics, Department for Clinical Biochemistry and Pharmacology, Odense University Hospital, Odense, Denmark
| | - Johannes F. Imhoff
- Research Unit Marine Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Antje Labes
- Research Unit Marine Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
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Morel M, Buée M, Chalot M, Brun A. NADP-dependent glutamate dehydrogenase: a dispensable function in ectomycorrhizal fungi. THE NEW PHYTOLOGIST 2006; 169:179-89. [PMID: 16390429 DOI: 10.1111/j.1469-8137.2005.01556.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
There is much controversy on the contribution of NADP-dependent glutamate dehydrogenase (NADP-GDH) in NH4+ assimilation in ectomycorrhizal (ECM) fungi and ectomycorrhizas. Experiments reported here provide information on the dispensability of NADP-GDH in various ectomycorrhizal isolates. Glutamate dehydrogenase and glutamine synthetase (GS) enzyme activities were measured on mycelia grown under various nitrogen (N) conditions. The contribution of GDH in ammonium assimilation was further estimated by following 15N incorporation from (15NH4)2SO4 into glutamate, when GS was inhibited by phosphinothricin. Finally, gene amplification on cDNA and genomic DNA was performed using degenerated primers. Two groups of fungi could be distinguished. The GDH+ fungi include Hebeloma cylindrosporum-like fungi, which possess a functional NADP-GDH. The GDH- fungi include Paxillus involutus-like fungi for which the NADP-GDH activity, as well as the GDHA transcripts, were not detected, whatever the growth condition. All the results are consistent with the dispensability of the NADP-GDH function in ECM fungi, suggesting a minor role in ammonium assimilation in ectomycorrhizal fungi. We hypothesize that the lack of a functional NADP-GDH could be an evolutive adaptation in relation to the ecological niche of ECM fungi, rather than a transitional regulation in response to changes in N contents of the extracellular medium.
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Affiliation(s)
- Mélanie Morel
- IFR 110, UMR INRA/UHP 1136 Interactions Arbres Micro-organismes, Université Henri Poincaré- Nancy I, Faculté des Sciences et Techniques BP239, F-54506 Vandoeuvre-les-Nancy Cedex, France
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Growth characteristics, nitrogen uptake and enzyme activities of the nitrate-utilising ectomycorrhizal Scleroderma verrucosum. ACTA ACUST UNITED AC 1999. [DOI: 10.1017/s0953756298008004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Chen H, Kinsey JA. Sequential gel mobility shift scanning of 5' upstream sequences of the Neurospora crassa am (GDH) gene. MOLECULAR & GENERAL GENETICS : MGG 1994; 242:399-403. [PMID: 8121395 DOI: 10.1007/bf00281789] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have used gel mobility shift assays to scan 1.7 kb of 5' non-coding sequence of the am (glutamate dehydrogenase) gene of Neurospora crassa for binding by partially fractionated Neurospora proteins. Using genetic analysis this region had been shown to play an important role in the control of glutamate dehydrogenase (GDH) expression. Gel mobility shift analysis identified three regions to which Neurospora proteins bind specifically. Two of these corresponded to the two elements previously defined by genetic analysis (URSam alpha and URSam beta). The third protein binding site appears to be unrelated to am gene expression. Competition experiments showed that the proteins that bind to the URSam alpha and URSam beta elements are different. The URSam alpha element was shown to contain two independent binding sites for the URSam alpha binding protein(s). Both fragments contain a CCAAT motif, suggesting that URSam alpha binding protein(s) may be members of one of the CCAAT-binding protein families. The effect of deletion of either the URSam alpha or URSam beta elements on catabolite induction of am expression was also determined. Both elements appear to act as constitutive enhancers of gene expression.
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Affiliation(s)
- H Chen
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City 66160-7420
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Bedell JP, Garnier A, Pireaux JC, Chalot M, Brun A, Botton B. Etude de quelques enzymes impliquées dans le métabolisme azoté de l'association ectomycorhizienne Douglas/Laccaria laccata. ACTA ACUST UNITED AC 1994. [DOI: 10.1080/12538078.1994.10515186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Calderón J, Martínez LM. Regulation of ammonium ion assimilation enzymes in Neurospora crassa nit-2 and ms-5 mutant strains. Biochem Genet 1993; 31:425-39. [PMID: 7907211 DOI: 10.1007/bf02396227] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In Neurospora crassa the nit-2 and nmr-1 (ms-5) loci represent the major control genes encoding regulatory proteins that allow the coordinated expression of various systems involved with the utilization of a secondary nitrogen source. In this paper we examined the effect of the nit-2 and ms-5 (nmr-1 locus) mutations on the regulation of the ammonium assimilation enzymes, glutamine synthetase and glutamate dehydrogenase, which are regulated by the products of these genes; however, glutamate synthase is not so regulated. Glutamine synthetase and glutamate dehydrogenase levels are also regulated by the amino nitrogen content. We present evidence that the ms-5 and glnr strains, which behave very similarly in their resistance to glutamine repression, are different and map in different loci.
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Affiliation(s)
- J Calderón
- Departamento de Ecología Molecular, Centro de Investigación sobre Fijación de Nitrógeno, UNAM Cuernavaca, Mor., México
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7
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Martin FM, Hilbert JL. Morphological, biochemical and molecular changes during ectomycorrhiza development. ACTA ACUST UNITED AC 1991. [DOI: 10.1007/bf01972073] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
Evidence for the existence of a glutamine cycle in Neurospora crassa is reviewed. Through this cycle glutamine is converted into glutamate by glutamate synthase and catabolized by the glutamine transaminase-omega-amidase pathway, the products of which (2-oxoglutarate and ammonium) are the substrates for glutamate dehydrogenase-NADPH, which synthesizes glutamate. In the final step ammonium is assimilated into glutamine by the action of a glutamine synthetase (GS), which is formed by two distinct polypeptides, one catalytically very active (GS beta), and the other (GS alpha) less active but endowed with the capacity to modulate the activity of GS alpha. Glutamate synthase uses the amide nitrogen of glutamine to synthesize glutamate; glutamate dehydrogenase uses ammonium, and both are required to maintain the level of glutamate. The energy expended in the synthesis of glutamine drives the cycle. The glutamine cycle is not futile, because it is necessary to drive an effective carbon flow to support growth; in addition, it facilitates the allocation of nitrogen or carbon according to cellular demands. The glutamine cycle which dissipates energy links catabolism and anabolism and, in doing so, buffers variations in the nutrient supply and drives energy generation and carbon flow for optimal cell function.
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Affiliation(s)
- J Mora
- Centro de Investigación Sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Cuernavaca, Morelos
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Frederick GD, Kinsey JA. Distant upstream regulatory sequences control the level of expression of the am (GDH) locus of Neurospora crassa. Curr Genet 1990; 18:53-8. [PMID: 2147126 DOI: 10.1007/bf00321115] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have constructed deletions in the 5' noncoding sequences of the cloned Neurospora crassa am gene. Vectors with a truncated fragment of the am gene were used in transformation experiments to introduce the deletions into the chromosome by homologous recombination. Analysis of glutamate dehydrogenase (GDH) expression by enzyme assay and immunoblots, as well as Northern and dot blots of poly (A)+ RNA, in the deletion strains indicates that there are two upstream regulatory sequences that control the level of gene expression. The closer of these two elements (URSam alpha) is at approximately 1.4 kb upstream of the transcriptional start site. The second elements (URSam beta) is located between 2.1 and 3.2 kb upstream of the transcription start site. Deletion of either of these two elements reduces am expression to about 50% of the wild-type level. Deletion of both elements reduce am expression to from 5-16% of the wild-type level. Deletion of 1.1 kb of sequence just downstream of URSam alpha, which brings this element to within 300 bp of the transcription start site, had no effect on am expression. Likewise, deletion of 3.5 kb of sequence upstream of URSam beta had no effect on expression. None of these deletions had any effect on the expression of usg-1, a gene of unknown function that is transcribed in the same direction as the am gene, and which terminates about 3.5 kb upstream of the URSam beta element.
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Affiliation(s)
- G D Frederick
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical School, Kansas City 66103
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Hipkin CR, Flynn KJ, Marjot E, Hamoudi ZS, Cannons AC. Ammonium assimilation by the nitrate-utilizing yeast, Candida nitratophila. THE NEW PHYTOLOGIST 1990; 114:429-434. [PMID: 33873966 DOI: 10.1111/j.1469-8137.1990.tb00410.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ammonium-nitrogen was assimilated rapidly by nitrogen-replete cultures of the nitrate-utilizing yeast, Candida nitratophila as long as a suitable source of carbon was available. These cultures contained high activities of an NADPH-dependent glutamate dehydrogenase with a relatively high affinity for ammonium (Km = 0.27 mM) and high glutamine synthetase activity. Both enzyme activities were apparently derepressed when glutamine-grown cultures were starved of nitrogen or transferred to nitrate medium. Nitrogen-deficient cultures also contained NADH-dependent glutamate synthase activity that was inhibited by azaserine in vitro. Ammonium assimilation in vivo, was inhibited by methionine sulphoximine whilst addition of azaserine resulted in an accumulation of intracellular glutamine and an inhibition of glutamate production. Our results suggest that, in C. nitratophila, there is a potential for ammonium assimilation via both the glutamate dehydrogenase pathway and the glutamine synthetase/glutamate synthase pathway with the latter pathway predominating in nitrogen-deficient cells.
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Affiliation(s)
- C R Hipkin
- Biochemistry Research Group, School of Biological Sciences, University College of Swansea, Singleton Park, Swansea, SA2 8PP, UK
| | - K J Flynn
- Biochemistry Research Group, School of Biological Sciences, University College of Swansea, Singleton Park, Swansea, SA2 8PP, UK
| | - E Marjot
- Biochemistry Research Group, School of Biological Sciences, University College of Swansea, Singleton Park, Swansea, SA2 8PP, UK
| | - Z S Hamoudi
- Biochemistry Research Group, School of Biological Sciences, University College of Swansea, Singleton Park, Swansea, SA2 8PP, UK
| | - A C Cannons
- Biochemistry Research Group, School of Biological Sciences, University College of Swansea, Singleton Park, Swansea, SA2 8PP, UK
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Martinez-Bilbao M, Martinez A, Urkijo I, Llama MJ, Serra JL. Induction, isolation, and some properties of the NADPH-dependent glutamate dehydrogenase from the nonheterocystous cyanobacterium Phormidium laminosum. J Bacteriol 1988; 170:4897-902. [PMID: 3139639 PMCID: PMC211535 DOI: 10.1128/jb.170.10.4897-4902.1988] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The level of the NADPH-dependent glutamate dehydrogenase activity (EC 1.4.1.4) from nitrate-grown cells of the thermophilic non-N2-fixing cyanobacterium Phormidium laminosum OH-1-p.Cl1 could be significantly enhanced by the presence of ammonium or nitrite, as well as by L-methionine-DL-sulfoximine and other sources of organic nitrogen (L-Glu, L-Gln, and methylamine). The enzyme was purified more than 4,400-fold by ultracentrifugation, ion-exchange chromatography, and affinity chromatography, and at 30 degrees C it showed a specific activity of 32.9 mumol of NADPH oxidized per min per mg of protein. The purified enzyme showed no aminotransferase activity and catalyzed the amination of 2-oxoglutarate preferentially to the reverse catabolic reaction. The enzyme was very specific for its substrates 2-oxoglutarate (Km = 1.25 mM) and NADPH (Km = 64 microM), for which hyperbolic kinetics were obtained. However, negative cooperativity (Hill coefficient h = 0.89) and [S]0.5 of 18.2 mM were observed for ammonium. The mechanism of the aminating reaction was of a random type with independent sites. The purified enzyme showed its maximal activity at 60 degrees C (Ea = 5.1 kcal/mol [21.3 kJ/mol]) and optimal pH values of 8.0 and 7.5 when assayed in Tris hydrochloride and potassium phosphate buffers, respectively. The native molecular mass of the enzyme was about 280 kilodaltons. The possible physiological role of the enzyme in ammonia assimilation is discussed.
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Affiliation(s)
- M Martinez-Bilbao
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad del País Vasco/Euskal Herriko, Unibertsitatea, Bilbao, Spain
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12
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Abstract
Mucor rouxii organisms growing aerobically and exponentially on a well-defined minimal medium are able to differentiate as yeasts or as mycelia, depending on the amino acid as the nitrogen source. When certain amino acids were used as the nitrogen source, spores differentiated only as hyphae, whereas other amino acids gave rise to other morphological forms having different ratios of yeasts to hyphae. In both hyphal and yeast cultures, an aerobic metabolism was predominant, as shown by determining several metabolic parameters such as oxygen tension, glucose consumption, ethanol production, and CO2 release. A complete conversion of yeasts to hyphae was obtained by the appropriate change in the amino acid used as nitrogen source. By preparing spheroplasts from mycelial cultures and transferring them to media with amino acids that induce yeast formation, a 50% yield in the reverse transformation was achieved. A correlation between the change in pH of the medium and cell morphology was observed in different growth conditions. Decrease in the pH of the medium preceded the appearance of hyphae. Also, when the initial pH of the medium was increased, aspartate-containing cultures developed mainly as mycelia, instead of yeasts, with a corresponding decrease in the final pH.
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13
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Hernández G, Mora Y, Mora J. Regulation of glutamine synthesis by glycine and serine in Neurospora crassa. J Bacteriol 1986; 165:133-8. [PMID: 2867084 PMCID: PMC214380 DOI: 10.1128/jb.165.1.133-138.1986] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The biosynthetic activities of the polypeptide subunits alpha and beta of glutamine synthetase (GS) were inhibited in vitro by glycine and serine. These amino acids inhibited the growth of a mutant strain with partial GS activity when grown on glutamate as the nitrogen source and also blocked the synthesis of the glutamine in vivo, thus demonstrating the inhibitory effect on GS activity in vivo. Glycine and serine lowered the intracellular glutamine pool and regulated GS beta synthesis. A preferential induction of synthesis of the GS beta polypeptide was observed when either of these amino acids was present in the medium. On this basis, we obtained a glycine-sensitive mutant which showed a structural alteration of the GS beta polypeptide. The double regulatory effect of either glycine or serine on glutamine synthesis may be considered an example of the regulation of glutamine synthesis by alpha-amino nitrogen. It may be a mechanism that regulates the assimilation of ammonium into glutamate versus glutamine.
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Glutamate pools and glutamate dehydrogenase regulation in relation to penicillin biosynthesis in strains of Penicillium chrysogenum. ACTA ACUST UNITED AC 1985. [DOI: 10.1016/0147-5975(85)90004-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Immunoelectrophoretic approach to the metabolic regulation of glutamine synthetase in Rhodopseudomonas capsulata E1F1: role of glutamine. Arch Microbiol 1985. [DOI: 10.1007/bf00411032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Kinzel JJ, Leslie JF. NADPH-dependent glutamate dehydrogenase activity inGibberella zeae. ACTA ACUST UNITED AC 1985. [DOI: 10.1016/0147-5975(85)90037-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Calderón J, Morett E, Mora J. Omega-amidase pathway in the degradation of glutamine in Neurospora crassa. J Bacteriol 1985; 161:807-9. [PMID: 2857167 PMCID: PMC214962 DOI: 10.1128/jb.161.2.807-809.1985] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Evidence for the participation of the glutamine transaminase-omega-amidase pathway in the utilization of glutamine in Neurospora crassa was obtained. Its participation is indicated by the in vitro activities of glutamine transaminase and omega-amidase, the in vivo accumulation of alpha-ketoglutaramate when an inhibitor of transamidases is present, and the inhibition by aminooxyacetic acid and 6-diazo-5-oxo-L-norleucine of the ammonium excreted in the presence of glutamine by a mutant strain that lacks glutamate dehydrogenase and glutamate synthase.
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Bogonez E, Satrústegui J, Machado A. The role of glutamate in modulating the synthesis and degradation of NADP-glutamate dehydrogenase from Saccharomyces cerevisiae. FEMS Microbiol Lett 1985. [DOI: 10.1111/j.1574-6968.1985.tb01565.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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