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Maicas S, Sánchez-Fresneda R, Solano F, Argüelles JC. The Enigma of NTH2 Gene in Yeasts. Microorganisms 2024; 12:1232. [PMID: 38930613 PMCID: PMC11206128 DOI: 10.3390/microorganisms12061232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/11/2024] [Accepted: 06/16/2024] [Indexed: 06/28/2024] Open
Abstract
The enzymatic hydrolysis of the non-reducing disaccharide trehalose in yeasts is carried out by trehalase, a highly specific α-glucosidase. Two types of such trehalase activity are present in yeasts, and are referred to as neutral and acid enzymes. They are encoded by distinct genes (NTH1 and ATH1, respectively) and exhibit strong differences in their biochemical and physiological properties as well as different subcellular location and regulatory mechanisms. Whereas a single gene ATH1 codes for acid trehalase, the genome of some yeasts appears to predict the existence of a second redundant neutral trehalase, encoded by the NTH2 gene, a paralog of NTH1. In S. cerevisiae the corresponding two proteins share 77% amino acid identity, leading to the suggestion that NTH2 codes for a functional trehalase activity. However, Nth2p lacks any measurable neutral trehalase activity and disruption of NTH2 gene has no effect on this activity compared to a parental strain. Likewise, single nth1Δ and double nth1Δ/nth2Δ null mutants display no detectable neutral activity. Furthermore, disruption of NTH2 does not cause any apparent phenotype apart from a slight involvement in thermotolerance. To date, no evidence of a duplicated NTH gene has been recorded in other archetypical yeasts, like C. albicans or C. parapsilosis, and a possible regulatory mechanism of Nth2p remains unknown. Therefore, although genomic analysis points to the existence, in some yeasts, of two distinct genes encoding trehalase activities, the large body of biochemical and physiological evidence gathered from NTH2 gene does not support this proposal. Indeed, much more experimental evidence would be necessary to firmly validate this hypothesis.
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Affiliation(s)
- Sergi Maicas
- Departament de Microbiologia i Ecologia, Facultat de Ciències Biològiques, Universitat de València, 46100 Burjassot, Spain
| | - Ruth Sánchez-Fresneda
- Área de Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain;
| | - Francisco Solano
- Departamento de Bioquímica y Biología Molecular B e Inmunología, Facultad de Medicina Campus de Ciencias de la Salud, Universidad de Murcia, 30120 Murcia, Spain;
| | - Juan-Carlos Argüelles
- Área de Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain;
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Mery A, Jawhara S, François N, Cornu M, Poissy J, Martinez-Esparza M, Poulain D, Sendid B, Guerardel Y. Identification of fungal trehalose for the diagnosis of invasive candidiasis by mass spectrometry. Biochim Biophys Acta Gen Subj 2022; 1866:130083. [PMID: 35033574 DOI: 10.1016/j.bbagen.2022.130083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/28/2021] [Accepted: 01/03/2022] [Indexed: 10/19/2022]
Abstract
The rapidity of the diagnosis of invasive candidiasis (IC) is crucial to allow the early introduction of antifungal therapy that dramatically increases the survival rate of patients. Early diagnosis is unfortunately often delayed because Candida blood culture, the gold standard diagnostic test, is positive in only 50% of cases of IC and takes several days to obtain this result. Complementary non-culture-based methods relying on the detection of Candida cell wall polysaccharides in the serum, β-glucans and mannans, by enzymatic and immunological reagents have been successfully developed to allow a more efficient patients care. We have previously demonstrated that detection of circulating glycans by mass spectrometry could provide a reliable and cost-effective early diagnosis method called MS-DS for Mass Spectrometry of Di-Saccharide. Here, by comparing patient's sera and Candida albicans strains deficient in carbohydrates synthesis, we demonstrate that trehalose derived from fungal metabolism can be specifically targeted by MS-DS to allow early diagnosis. In particular, the use of C. albicans strains deficient in the synthesis of trehalose synthesizing enzymes Tps1 and Tps2 show that MS-DS results were correlated to the metabolism of trehalose. Finally, we demonstrate that the performance of the IC diagnosis can be significantly improved by using high resolution mass spectrometry, which opens new perspectives in the management of the disease.
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Affiliation(s)
- Alexandre Mery
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Samir Jawhara
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France; Univ. Lille, Inserm U1285, CHU Lille, Laboratoire de Parasitologie-Mycologie, Lille, France
| | - Nadine François
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France; Univ. Lille, Inserm U1285, CHU Lille, Laboratoire de Parasitologie-Mycologie, Lille, France
| | - Marjorie Cornu
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France; Univ. Lille, Inserm U1285, CHU Lille, Laboratoire de Parasitologie-Mycologie, Lille, France
| | - Julien Poissy
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France; Univ. Lille, Inserm U1285, CHU Lille, Pôle de réanimation, Lille, France
| | - Maria Martinez-Esparza
- Departamento de Bioquímica, Biología Molecular (B) e Inmunología, Facultad de Medicina, IMIB-Arrixaca and Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia, Spain
| | - Daniel Poulain
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France; Univ. Lille, Inserm U1285, CHU Lille, Laboratoire de Parasitologie-Mycologie, Lille, France
| | - Boualem Sendid
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France; Univ. Lille, Inserm U1285, CHU Lille, Laboratoire de Parasitologie-Mycologie, Lille, France
| | - Yann Guerardel
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France; Institute for Glyco-core Research (iGCORE), Gifu University, Gifu, Japan.
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Van Ende M, Timmermans B, Vanreppelen G, Siscar-Lewin S, Fischer D, Wijnants S, Romero CL, Yazdani S, Rogiers O, Demuyser L, Van Zeebroeck G, Cen Y, Kuchler K, Brunke S, Van Dijck P. The involvement of the Candida glabrata trehalase enzymes in stress resistance and gut colonization. Virulence 2021; 12:329-345. [PMID: 33356857 PMCID: PMC7808424 DOI: 10.1080/21505594.2020.1868825] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 11/28/2020] [Accepted: 12/17/2020] [Indexed: 12/29/2022] Open
Abstract
Candida glabrata is an opportunistic human fungal pathogen and is frequently present in the human microbiome. It has a high relative resistance to environmental stresses and several antifungal drugs. An important component involved in microbial stress tolerance is trehalose. In this work, we characterized the three C. glabrata trehalase enzymes Ath1, Nth1 and Nth2. Single, double and triple deletion strains were constructed and characterized both in vitro and in vivo to determine the role of these enzymes in virulence. Ath1 was found to be located in the periplasm and was essential for growth on trehalose as sole carbon source, while Nth1 on the other hand was important for oxidative stress resistance, an observation which was consistent by the lower survival rate of the NTH1 deletion strain in human macrophages. No significant phenotype was observed for Nth2. The triple deletion strain was unable to establish a stable colonization of the gastrointestinal (GI) tract in mice indicating the importance of having trehalase activity for colonization in the gut.
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Affiliation(s)
- Mieke Van Ende
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Bea Timmermans
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Giel Vanreppelen
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Sofía Siscar-Lewin
- Department of Microbial Pathogenicity Mechanisms, Hans Knöll Institute, Jena, Germany
| | - Daniel Fischer
- Department of Microbial Pathogenicity Mechanisms, Hans Knöll Institute, Jena, Germany
| | - Stefanie Wijnants
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Celia Lobo Romero
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Saleh Yazdani
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Ona Rogiers
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
- VIB-UGent Center for Inflammation Research, Ghent, VIB, Belgium
| | - Liesbeth Demuyser
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Griet Van Zeebroeck
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Yuke Cen
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Karl Kuchler
- Medical University of Vienna, Center for Medical Biochemistry, Max Perutz Labs Vienna, Campus Vienna Biocenter, Vienna, Austria
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Hans Knöll Institute, Jena, Germany
| | - Patrick Van Dijck
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, Leuven, KU Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
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Qadri H, Qureshi MF, Mir MA, Shah AH. Glucose - The X factor for the survival of human fungal pathogens and disease progression in the host. Microbiol Res 2021; 247:126725. [PMID: 33676311 DOI: 10.1016/j.micres.2021.126725] [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: 10/03/2020] [Revised: 01/11/2021] [Accepted: 02/10/2021] [Indexed: 01/04/2023]
Abstract
The incidence of human fungal infections is increasing due to the expansion of the immunocompromised patient population. The continuous use of different antifungal agents has eventually resulted in the establishment of resistant fungal species. The fungal pathogens unfold multiple resistance strategies to successfully tackle the effect of different antifungal agents. For the successful colonization and establishment of infection inside the host, the pathogenic fungi switch to the process of metabolic flexibility to regulate distinct nutrient uptake systems as well as to modulate their metabolism accordingly. Glucose the most favourable carbon source helps carry out the important survival and niche colonization processes. Adopting glucose as the center, this review has been put forward to provide an outline of the important processes like growth, the progression of infection, and the metabolism regulated by glucose, affecting the pathogenicity and virulence traits in the human pathogenic fungi. This could help in the identification of better treatment options and appropriate target-oriented antifungal drugs based on the glucose-regulated pathways and processes. In the article, we have also presented a summary of the novel studies and findings pointing to glucose-based potential therapeutic avenues to be explored to tackle the problem of globally increasing multidrug-resistant human fungal infections.
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Affiliation(s)
- Hafsa Qadri
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Hazratbal, Srinagar, 190006, J&K, India
| | - Munazah Fazal Qureshi
- Department of Biotechnology, Central University of Kashmir, Ganderbal, 191201, J&K, India
| | - Manzoor Ahmad Mir
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Hazratbal, Srinagar, 190006, J&K, India.
| | - Abdul Haseeb Shah
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Hazratbal, Srinagar, 190006, J&K, India.
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Antifungal Resistance, Metabolic Routes as Drug Targets, and New Antifungal Agents: An Overview about Endemic Dimorphic Fungi. Mediators Inflamm 2017; 2017:9870679. [PMID: 28694566 PMCID: PMC5485324 DOI: 10.1155/2017/9870679] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/28/2017] [Accepted: 05/23/2017] [Indexed: 12/30/2022] Open
Abstract
Diseases caused by fungi can occur in healthy people, but immunocompromised patients are the major risk group for invasive fungal infections. Cases of fungal resistance and the difficulty of treatment make fungal infections a public health problem. This review explores mechanisms used by fungi to promote fungal resistance, such as the mutation or overexpression of drug targets, efflux and degradation systems, and pleiotropic drug responses. Alternative novel drug targets have been investigated; these include metabolic routes used by fungi during infection, such as trehalose and amino acid metabolism and mitochondrial proteins. An overview of new antifungal agents, including nanostructured antifungals, as well as of repositioning approaches is discussed. Studies focusing on the development of vaccines against antifungal diseases have increased in recent years, as these strategies can be applied in combination with antifungal therapy to prevent posttreatment sequelae. Studies focused on the development of a pan-fungal vaccine and antifungal drugs can improve the treatment of immunocompromised patients and reduce treatment costs.
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Central Role of the Trehalose Biosynthesis Pathway in the Pathogenesis of Human Fungal Infections: Opportunities and Challenges for Therapeutic Development. Microbiol Mol Biol Rev 2017; 81:81/2/e00053-16. [PMID: 28298477 DOI: 10.1128/mmbr.00053-16] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Invasive fungal infections cause significant morbidity and mortality in part due to a limited antifungal drug arsenal. One therapeutic challenge faced by clinicians is the significant host toxicity associated with antifungal drugs. Another challenge is the fungistatic mechanism of action of some drugs. Consequently, the identification of fungus-specific drug targets essential for fitness in vivo remains a significant goal of medical mycology research. The trehalose biosynthetic pathway is found in a wide variety of organisms, including human-pathogenic fungi, but not in humans. Genes encoding proteins involved in trehalose biosynthesis are mechanistically linked to the metabolism, cell wall homeostasis, stress responses, and virulence of Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. While there are a number of pathways for trehalose production across the tree of life, the TPS/TPP (trehalose-6-phosphate synthase/trehalose-6-phosphate phosphatase) pathway is the canonical pathway found in human-pathogenic fungi. Importantly, data suggest that proteins involved in trehalose biosynthesis play other critical roles in fungal metabolism and in vivo fitness that remain to be fully elucidated. By further defining the biology and functions of trehalose and its biosynthetic pathway components in pathogenic fungi, an opportunity exists to leverage this pathway as a potent antifungal drug target. The goal of this review is to cover the known roles of this important molecule and its associated biosynthesis-encoding genes in the human-pathogenic fungi studied to date and to employ these data to critically assess the opportunities and challenges facing development of this pathway as a therapeutic target.
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Perfect JR, Tenor JL, Miao Y, Brennan RG. Trehalose pathway as an antifungal target. Virulence 2017; 8:143-149. [PMID: 27248439 PMCID: PMC5383216 DOI: 10.1080/21505594.2016.1195529] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/18/2016] [Accepted: 05/20/2016] [Indexed: 01/23/2023] Open
Abstract
With an increasing immunocompromised population which is linked to invasive fungal infections, it is clear that our present 3 classes of antifungal agents may not be sufficient to provide optimal management to these fragile patients. Furthermore, with widespread use of antifungal agents, drug-resistant fungal infections are on the rise. Therefore, there is some urgency to develop the antifungal pipeline with the goal of new antifungal agent discovery. In this review, a simple metabolic pathway, which forms the disaccharide, trehalose, will be characterized and its potential as a focus for antifungal target(s) explained. It possesses several important features for development of antifungal agents. First, it appears to have fungicidal characteristics and second, it is broad spectrum with importance across both ascomycete and basidiomycete species. Finally, this pathway is not found in mammals so theoretically specific inhibitors of the trehalose pathway and its enzymes in fungi should be relatively non-toxic for mammals. The trehalose pathway and its critical enzymes are now in a position to have directed antifungal discovery initiated in order to find a new class of antifungal drugs.
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Affiliation(s)
- John R. Perfect
- Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC, USA
| | - Jennifer L. Tenor
- Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC, USA
| | - Yi Miao
- Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC, USA
| | - Richard G. Brennan
- Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC, USA
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Maicas S, Guirao-Abad JP, Argüelles JC. Yeast trehalases: Two enzymes, one catalytic mission. Biochim Biophys Acta Gen Subj 2016; 1860:2249-54. [DOI: 10.1016/j.bbagen.2016.04.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/19/2016] [Accepted: 04/27/2016] [Indexed: 01/08/2023]
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Sánchez-Fresneda R, Guirao-Abad JP, Martinez-Esparza M, Maicas S, Valentín E, Argüelles JC. Homozygous deletion of ATC1 and NTC1 genes in Candida parapsilosis abolishes trehalase activity and affects cell growth, sugar metabolism, stress resistance, infectivity and biofilm formation. Fungal Genet Biol 2015; 85:45-57. [PMID: 26529381 DOI: 10.1016/j.fgb.2015.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/26/2015] [Accepted: 10/31/2015] [Indexed: 12/16/2022]
Abstract
A double homozygous atc1Δ/atc1Δ/ntc1Δ/ntc1Δ mutant (atc1Δ/ntc1Δ KO) was constructed in the pathogen opportunistic yeast Candida parapsilosis by disruption of the two chromosomal alleles coding for NTC1 gene (encoding a neutral trehalase) in a Cpatc1Δ/atc1Δ background (atc1Δ KO strain, deficient in acid trehalase). The Cpatc1Δ/ntc1Δ KO mutant failed to counteract the inability of Cpatc1Δ cells to metabolize exogenous trehalose and showed a similar growth pattern on several monosaccharides and disaccharides. However, upon prolonged incubation in either rich medium (YPD) or nutrient-starved medium the viability of Cpatc1Δ cells exhibited a sensitive phenotype, which was augmented by further CpNTC1/NTC1 disruption. Furthermore, Cpatc1Δ/ntc1Δ KO cells had difficulty in resuming active growth in fresh YPD. This homozygous mutant also lacked any in vitro measurable trehalase activity, whether acid or neutral, suggesting that a single gene codes for each enzyme. By contrast, in Cpatc1Δ/ntc1Δ KO strain the resistance to oxidative and heat stress displayed by atc1Δ mutant was suppressed. Cpatc1Δ/ntc1Δ KO cells showed a significant decrease in virulence as well as in the capacity to form biofilms. These results point to a major role for acid trehalase (Atc1p) in the pathobiology of C. parapsilosis, whereas the activity of neutral trehalase can only partially counteract Atc1p deficiency. They also support the use of ATC1 and NTC1 genes as interesting antifungal targets.
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Affiliation(s)
- Ruth Sánchez-Fresneda
- Área de Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; IMIB-Arrixaca, Spain; Departamento de Microbiología y Ecología, Facultad de Farmacia, Universidad de Valencia, 46100 Burjassot, Valencia, Spain
| | - José P Guirao-Abad
- Área de Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; IMIB-Arrixaca, Spain
| | - María Martinez-Esparza
- Departamento de Bioquímica, Biología Molecular (B) e Inmunología, Facultad de Medicina, Universidad de Murcia, 30100 Murcia, Spain; IMIB-Arrixaca, Spain
| | - Sergi Maicas
- Departamento de Microbiología y Ecología, Facultad de Biología, Universidad de Valencia, 46100 Burjassot, Valencia, Spain
| | - Eulogio Valentín
- Departamento de Microbiología y Ecología, Facultad de Farmacia, Universidad de Valencia, 46100 Burjassot, Valencia, Spain
| | - Juan-Carlos Argüelles
- Área de Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; IMIB-Arrixaca, Spain.
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Pereira MG, Guimarães LHS, Furriel RPM, Polizeli MDLTDM, Terenzi HF, Jorge JA. Biochemical properties of an extracellular trehalase from Malbranchea pulchella var. Sulfurea. J Microbiol 2011; 49:809-15. [PMID: 22068499 DOI: 10.1007/s12275-011-0532-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 04/27/2011] [Indexed: 11/28/2022]
Abstract
The thermophilic fungus Malbranchea pulchella var. sulfurea produced good amounts of extracellular trehalase activity when grown for long periods on starch, maltose or glucose as the main carbon source. Studies with young cultures suggested that the main role of the extracellular acid trehalase is utilizing trehalose as a carbon source. The specific activity of the purified enzyme in the presence of manganese (680 U/mg protein) was comparable to that of other thermophilic fungi enzymes, but many times higher than the values reported for trehalases from other microbial sources. The apparent molecular mass of the native enzyme was estimated to be 104 kDa by gel filtration and 52 kDa by SDS-PAGE, suggesting that the enzyme was composed by two subunits. The carbohydrate content of the purified enzyme was estimated to be 19 % and the pi was 3.5. The optimum pH and temperature were 5.0-5.5 and 55° C, respectively. The purified enzyme was stimulated by manganese and inhibited by calcium ions, and insensitive to ATP and ADP, and 1 mM silver ions. The apparent K(M) values for trehalose hydrolysis by the purified enzyme in the absence and presence of manganese chloride were 2.70 ± 0.29 and 2.58 ± 0.13 mM, respectively. Manganese ions affected only the apparent V(max), increasing the catalytic efficiency value by 9.2-fold. The results reported herein indicate that Malbranchea pulchella produces a trehalase with mixed biochemical properties, different from the conventional acid and neutral enzymes and also from trehalases from other thermophilic fungi.
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Affiliation(s)
- Marita Gimenez Pereira
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes, 3900, CEP 14040-901, Ribeirão Preto, SP, Brasil
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Chen J, Tang B, Chen H, Yao Q, Huang X, Chen J, Zhang D, Zhang W. Different functions of the insect soluble and membrane-bound trehalase genes in chitin biosynthesis revealed by RNA interference. PLoS One 2010; 5:e10133. [PMID: 20405036 PMCID: PMC2853572 DOI: 10.1371/journal.pone.0010133] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Accepted: 03/22/2010] [Indexed: 11/19/2022] Open
Abstract
Background Trehalase, an enzyme that hydrolyzes trehalose to yield two glucose molecules, plays a pivotal role in various physiological processes. In recent years, trehalase proteins have been purified from several insect species and are divided into soluble (Tre-1) and membrane-bound (Tre-2) trehalases. However, no functions of the two trehalases in chitin biosynthesis in insects have yet been reported. Principal Findings The membrane-bound trehalase of Spodoptera exigua (SeTre-2) was characterized in our laboratory previously. In this study, we cloned the soluble trehalase gene (SeTre-1) and investigated the tissue distribution and developmental expression pattern of the two trehalase genes. SeTre-1 was expressed highly in cuticle and Malpighian tubules, while SeTre-2 was expressed in tracheae and fat body. In the midgut, the two trehalase genes were expressed in different locations. Additionally, the expression profiles of both trehalase mRNAs and their enzyme activities suggest that they may play different roles in chitin biosynthesis. The RNA interference (RNAi) of either SeTre-1 or SeTre-2 was gene-specific and effective, with efficiency rates up to 83% at 72 h post injection. After RNAi of SeTre-1 and SeTre-2, significant higher mortality rates were observed during the larva-pupa stage and pupa-adult stage, and the lethal phenotypes were classified and analyzed. Additionally, the change trends of concentration of trehalose and glucose appeared reciprocally in RNAi-mutants. Moreover, knockdown of SeTre-1 gene largely inhibited the expression of chitin synthase gene A (CHSA) and reduced the chitin content in the cuticle to two-thirds relative to the control insects. The chitin synthase gene B (CHSB) expression, however, was inhibited more by the injection of dsRNA for SeTre-2, and the chitin content in the midgut decreased by about 25%. Conclusions SeTre-1 plays a major role in CHSA expression and chitin synthesis in the cuticle, and SeTre-2 has an important role in CHSB expression and chitin synthesis in the midgut.
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Affiliation(s)
- Jie Chen
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Bin Tang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Hangzhou Key Laboratory of Animal Adaptation and Evolution, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Hongxin Chen
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Qiong Yao
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xiaofeng Huang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jing Chen
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Daowei Zhang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wenqing Zhang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- * E-mail:
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Current awareness on yeast. Yeast 2009. [DOI: 10.1002/yea.1626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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