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Schaff H, Dey P, Heiss C, Keiser G, Moro TR, Azadi P, Patel P, Free SJ. Characterization of the need for galactofuranose during the Neurospora crassa life cycle. Fungal Genet Biol 2023; 168:103826. [PMID: 37541569 DOI: 10.1016/j.fgb.2023.103826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
Galactofuranose is a constituent of the cell walls of filamentous fungi. The galactofuranose can be found as a component of N-linked oligosaccharides, in O-linked oligosaccharides, in GPI-anchored galactomannan, and in free galactomannan. The Neurospora genome contains a single UDP-galactose mutase gene (ugm-1/NCU01824) and two UDP-galactofuranose translocases used to import UDP-galactofuranose into the lumen of the Golgi apparatus (ugt-1/NCU01826 and ugt-2/NCU01456). Our results demonstrate that loss of galactofuranose synthesis or its translocation into the lumen of the secretory pathway affects the morphology and growth rate of the vegetative hyphae, the production of conidia (asexual spores), and dramatically affects the sexual stages of the life cycle. In mutants that are unable to make galactofuranose or transport it into the lumen of the Golgi apparatus, ascospore development is aborted soon after fertilization and perithecium maturation is aborted prior to the formation of the neck and ostiole. The Neurospora genome contains three genes encoding possible galactofuranosyltransferases from the GT31 family of glycosyltransferases (gfs-1/NCU05878, gfs-2/NCU07762, and gfs-3/NCU02213) which might be involved in generating galactofuranose-containing oligosaccharide structures. Analysis of triple KO mutants in GT31 glycosyltransferases shows that these mutants have normal morphology, suggesting that these genes do not encode vital galactofuranosyltransferases.
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Affiliation(s)
- Hayden Schaff
- Dept. of Biological Sciences, SUNY University at Buffalo, Buffalo, NY 14260, United States
| | - Protyusha Dey
- Dept. of Biological Sciences, SUNY University at Buffalo, Buffalo, NY 14260, United States
| | - Christian Heiss
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, United States
| | - Griffin Keiser
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, United States
| | - Tatiana Rojo Moro
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, United States
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, United States
| | - Pavan Patel
- Dept. of Biological Sciences, SUNY University at Buffalo, Buffalo, NY 14260, United States
| | - Stephen J Free
- Dept. of Biological Sciences, SUNY University at Buffalo, Buffalo, NY 14260, United States.
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Son YE, Yu JH, Park HS. Regulators of the Asexual Life Cycle of Aspergillus nidulans. Cells 2023; 12:1544. [PMID: 37296664 PMCID: PMC10253035 DOI: 10.3390/cells12111544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/12/2023] Open
Abstract
The genus Aspergillus, one of the most abundant airborne fungi, is classified into hundreds of species that affect humans, animals, and plants. Among these, Aspergillus nidulans, as a key model organism, has been extensively studied to understand the mechanisms governing growth and development, physiology, and gene regulation in fungi. A. nidulans primarily reproduces by forming millions of asexual spores known as conidia. The asexual life cycle of A. nidulans can be simply divided into growth and asexual development (conidiation). After a certain period of vegetative growth, some vegetative cells (hyphae) develop into specialized asexual structures called conidiophores. Each A. nidulans conidiophore is composed of a foot cell, stalk, vesicle, metulae, phialides, and 12,000 conidia. This vegetative-to-developmental transition requires the activity of various regulators including FLB proteins, BrlA, and AbaA. Asymmetric repetitive mitotic cell division of phialides results in the formation of immature conidia. Subsequent conidial maturation requires multiple regulators such as WetA, VosA, and VelB. Matured conidia maintain cellular integrity and long-term viability against various stresses and desiccation. Under appropriate conditions, the resting conidia germinate and form new colonies, and this process is governed by a myriad of regulators, such as CreA and SocA. To date, a plethora of regulators for each asexual developmental stage have been identified and investigated. This review summarizes our current understanding of the regulators of conidial formation, maturation, dormancy, and germination in A. nidulans.
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Affiliation(s)
- Ye-Eun Son
- Major in Food Biomaterials, School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea;
| | - Jae-Hyuk Yu
- Department of Bacteriology, Food Research Institute, University of Wisconsin-Madison, Madison, WI 53706, USA;
| | - Hee-Soo Park
- Major in Food Biomaterials, School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea;
- Department of Integrative Biology, Kyungpook National University, Daegu 41566, Republic of Korea
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UDP-Galactopyranose Mutase Mediates Cell Wall Integrity, Polarity Growth, and Virulence in Fusarium graminearum. Appl Environ Microbiol 2023; 89:e0123522. [PMID: 36656025 PMCID: PMC9972967 DOI: 10.1128/aem.01235-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
CHY1 is a zinc finger protein unique to microorganisms that was found to regulate polarized tip growth in Fusarium graminearum, an important pathogen of wheat and barley. To further characterize its functions, in this study we identified CHY1-interacting proteins by affinity purification and selected UDP-galactofuranose (Galf) mutase (UGMA) for detailed characterization, because UGMA and UDP-Galf are unique to fungi and bacteria and absent in plants and animals. The interaction between CHY1 and UGMA was confirmed by yeast two-hybrid assays. Deletion of UGMA in F. graminearum resulted in significant defects in vegetative growth, reproduction, cell wall integrity, and pathogenicity. Infection with the ΔugmA mutant was restricted to the inoculated floret, and no vomitoxin was detected in kernels inoculated with the ΔugmA strain. Compared to the wild type, the ΔugmA mutant produced wide, highly branched hyphae with thick walls, as visualized by transmission electron microscopy. UGMA tagged with green fluorescent protein (GFP) mainly localized to the cytoplasm, consistent with the synthesis of Galf in the cytoplasm. The Δchy1 mutant was more sensitive, while the ΔugmA mutant was more tolerant, to cell wall-degrading enzymes. The growth of the ΔugmA mutant nearly ceased upon caspofungin treatment. More interestingly, nocodazole treatment of the ΔugmA strain attenuated its highly branched morphology, while caspofungin inhibited the degree of the twisted Δchy1 mycelia, indicating that CHY1 and UGMA probably have opposite effects on cell wall architecture. In conclusion, UGMA is an important pathogenic factor that is specific to fungi and bacteria and required for cell wall architecture, radial growth, and caspofungin tolerance, and it appears to be a promising target for antifungal agent development. IMPORTANCE The long-term use of chemical pesticides has had increasingly negative impacts on the ecological environment and human health. Low-toxicity, high-efficiency and environmentally friendly alternative pesticides are of great significance for maintaining the sustainable development of agriculture and human and environmental health. Using fungus- or microbe-specific genes as candidate targets provides a good foundation for the development of low-toxicity, environmentally friendly pesticides. In this study, we characterized a fungus- and bacterium-specific UDP-galactopyranose mutase gene, ugmA, that contributes to the synthesis of the cell wall component Galf and is required for vegetative growth, cell wall integrity, deoxynivalenol (DON) production, and pathogenicity in F. graminearum. The ugmA deletion mutant exhibited increased sensitivity to caspofungin. These results demonstrate the functional importance of UGMA in F. graminearum, and its absence from mammals and higher plants constitutes a considerable advantage as a low-toxicity target for the development of new anti-Fusarium agents.
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Kadooka C, Tanaka Y, Hira D, Maruyama JI, Goto M, Oka T. Identification of galactofuranose antigens such as galactomannoproteins and fungal-type galactomannan from the yellow koji fungus ( Aspergillus oryzae). Front Microbiol 2023; 14:1110996. [PMID: 36814571 PMCID: PMC9939772 DOI: 10.3389/fmicb.2023.1110996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/16/2023] [Indexed: 02/08/2023] Open
Abstract
Filamentous fungi belonging to the genus Aspergillus are known to possess galactomannan in their cell walls. Galactomannan is highly antigenic to humans and has been reported to be involved in the pathogenicity of pathogenic filamentous fungi, such as A. fumigatus, and in immune responses. In this study, we aimed to confirm the presence of D-galactofuranose-containing glycans and to clarify the biosynthesis of D-galactofuranose-containing glycans in Aspergillus oryzae, a yellow koji fungus. We found that the galactofuranose antigen is also present in A. oryzae. Deletion of ugmA, which encodes UDP-galactopyranose mutase in A. oryzae, suppressed mycelial elongation, suggesting that D-galactofuranose-containing glycans play an important role in cell wall integrity in A. oryzae. Proton nuclear magnetic resonance spectrometry revealed that the galactofuranose-containing sugar chain was deficient and that core mannan backbone structures were present in ΔugmA A. oryzae, indicating the presence of fungal-type galactomannan in the cell wall fraction of A. oryzae. The findings of this study provide new insights into the cell wall structure of A. oryzae, which is essential for the production of fermented foods in Japan.
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Affiliation(s)
- Chihiro Kadooka
- Department of Biotechnology and Life Sciences, Faculty of Biotechnology and Life Sciences, Sojo University, Kumamoto, Japan
| | - Yutaka Tanaka
- Division of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Daisuke Hira
- Department of Biotechnology and Life Sciences, Faculty of Biotechnology and Life Sciences, Sojo University, Kumamoto, Japan
| | - Jun-ichi Maruyama
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Masatoshi Goto
- Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga, Japan
| | - Takuji Oka
- Department of Biotechnology and Life Sciences, Faculty of Biotechnology and Life Sciences, Sojo University, Kumamoto, Japan,*Correspondence: Takuji Oka,
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van Leeuwe TM, Arentshorst M, Punt PJ, Ram AF. Interrogation of the cell wall integrity pathway in Aspergillus niger identifies a putative negative regulator of transcription involved in chitin deposition. Gene 2021; 763S:100028. [PMID: 32550555 PMCID: PMC7285910 DOI: 10.1016/j.gene.2020.100028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/18/2019] [Accepted: 01/23/2020] [Indexed: 01/26/2023]
Abstract
Post-fermentation fungal biomass waste provides a viable source for chitin. Cell wall chitin of filamentous fungi, and in particular its de-N-acetylated derivative chitosan, has a wide range of commercial applications. Although the cell wall of filamentous fungi comprises 10–30% chitin, these yields are too low for cost-effective production. Therefore, we aimed to identify the genes involved in increased chitin deposition by screening a collection of UV-derived cell wall mutants in Aspergillus niger. This screen revealed a mutant strain (RD15.4#55) that showed a 30–40% increase in cell wall chitin compared to the wild type. In addition to the cell wall chitin phenotype, this strain also exhibited sensitivity to SDS and produces an unknown yellow pigment. Genome sequencing combined with classical genetic linkage analysis identified two mutated genes on chromosome VII that were linked with the mutant phenotype. Single gene knockouts and subsequent complementation analysis revealed that an 8 bp deletion in NRRL3_09595 is solely responsible for the associated phenotypes of RD15.4#55. The mutated gene, which was named cwcA (cell wall chitin A), encodes an orthologue of Saccharomyces cerevisiae Bypass of ESS1 (BYE1), a negative regulator of transcription elongation. We propose that this conserved fungal protein is involved in preventing cell wall integrity signaling under non-inducing conditions, where loss of function results in constitutive activation of the cell wall stress response pathway, and consequently leads to increased chitin content in the mutant cell wall. An Aspergillus niger UV-mutant with increased cell wall chitin was characterized. Causative mutation was identified in a single gene, named cell wall chitin A (cwcA). CwcA is orthologous to yeast Bye1p and exists as a single copy gene. Three relevant domains are found in both CwcA and Bye1p: PHD, TFIIS and SPOC. CwcA acts as negative regulator of CWI signaling.
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Affiliation(s)
- Tim M. van Leeuwe
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Mark Arentshorst
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Peter J. Punt
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands
- Dutch DNA Biotech, Hugo R Kruytgebouw 4-Noord, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Arthur F.J. Ram
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands
- Corresponding author at: Leiden University, Institute of Biology, Department Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands.
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Zhou H, Xu Y, Ebel F, Jin C. Galactofuranose (Galf)-containing sugar chain contributes to the hyphal growth, conidiation and virulence of F. oxysporum f.sp. cucumerinum. PLoS One 2021; 16:e0250064. [PMID: 34329342 PMCID: PMC8323920 DOI: 10.1371/journal.pone.0250064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/31/2021] [Indexed: 01/14/2023] Open
Abstract
The ascomycete fungus Fusarium oxysporum f.sp. cucumerinum causes vascular wilt diseases in cucumber. However, few genes related to morphogenesis and pathogenicity of this fungal pathogen have been functionally characterized. BLASTp searches of the Aspergillus fumigatus UgmA and galatofuranosyltransferases (Galf-transferases) sequences in the F. oxysporum genome identified two genes encoding putative UDP-galactopyranose mutase (UGM), ugmA and ugmB, and six genes encoding putative Galf-transferase homologs. In this study, the single and double mutants of the ugmA, ugmB and gfsB were obtained. The roles of UGMs and GfsB were investigated by analyzing the phenotypes of the mutants. Our results showed that deletion of the ugmA gene led to a reduced production of galactofuranose-containing sugar chains, reduced growth and impaired conidiation of F. oxysporum f.sp. cucumerinum. Most importantly, the ugmA deletion mutant lost the pathogenicity in cucumber plantlets. Although deletion of the ugmB gene did not cause any visible phenotype, deletion of both ugmA and ugmB genes caused more severe phenotypes as compared with the ΔugmA, suggesting that UgmA and UgmB are redundant and they can both contribute to synthesis of UDP-Galf. Furthermore, the ΔgfsB exhibited an attenuated virulence although no other phenotype was observed. Our results demonstrate that the galactofuranose (Galf) synthesis contributes to the cell wall integrity, germination, hyphal growth, conidiation and virulence in Fusarium oxysporum f.sp. cucumerinum and an ideal target for the development of new anti-Fusarium agents.
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Affiliation(s)
- Hui Zhou
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yueqiang Xu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Frank Ebel
- Institute for Infectious Diseases and Zoonoses, LMU, Munich, Germany
| | - Cheng Jin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- National Engineering Research Center for Non-food Bio-refinery, Guangxi Academy of Sciences, Nanning, China
- * E-mail:
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Matsunaga E, Tanaka Y, Toyota S, Yamada H, Oka T, Higuchi Y, Takegawa K. Identification and characterization of β-d-galactofuranosidases from Aspergillus nidulans and Aspergillus fumigatus. J Biosci Bioeng 2020; 131:1-7. [PMID: 33011078 DOI: 10.1016/j.jbiosc.2020.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/08/2020] [Accepted: 09/09/2020] [Indexed: 11/29/2022]
Abstract
Although β-d-galactofuranosidases (Galf-ases) that hydrolyze β-d-galactofuranose (Galf)-containing oligosaccharides have been characterized in various organisms, to date no Galf-specific Galf-ase-encoding genes have been reported in Aspergillus fungi. Based on the amino acid sequences of previously identified bacterial Galf-ases, here we found two candidate Galf-specific Galf-ase genes AN2395 (gfgA) and AN3200 (gfgB) in the genome of Aspergillus nidulans. Indeed, recombinant GfgA and GfgB proteins exhibited Galf-specific Galf-ase activity, but no detectable α-l-arabinofuranosidase (Araf-ase) activity. Phylogenetic analysis of GfgA and GfgB orthologs indicated that there are two types of Aspergillus species: those containing one ortholog each for GfgA and GfgB; and those containing only one ortholog in total, among which Aspergillus fumigatus there is a representative with a single ortholog Galf-ase Afu2g14520. Unlike GfgA and GfgB, the recombinant Afu2g14520 protein showed higher Araf-ase activity than Galf-ase activity. An assay of substrate specificity revealed that although GfgA and GfgB are both exo-type Galf-ases and hydrolyze β-(1,5) and β-(1,6) linkages, GfgA hydrolyzes β-(1,6)-linked Galf-oligosaccharide more effectively as compared with GfgB. Collectively, our findings indicate that Galf-ases in Aspergillus species may have a role in cooperatively degrading Galf-containing oligosaccharides depending on environmental conditions.
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Affiliation(s)
- Emiko Matsunaga
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yutaka Tanaka
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, Sendai 981-8558, Japan
| | - Saki Toyota
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hisae Yamada
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Kumamoto 860-0082, Japan
| | - Yujiro Higuchi
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kaoru Takegawa
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
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Pham TA, Kyriacou BA, Schwerdt JG, Shirley NJ, Xing X, Bulone V, Little A. Composition and biosynthetic machinery of the Blumeria graminis f. sp. hordei conidia cell wall. ACTA ACUST UNITED AC 2020; 5:100029. [PMID: 32743145 PMCID: PMC7388969 DOI: 10.1016/j.tcsw.2019.100029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 08/08/2019] [Accepted: 08/08/2019] [Indexed: 01/01/2023]
Abstract
Infection of barley with the powdery mildew causal agent, Blumeria graminis f. sp. hordei (Bgh), can lead to devastating damage to barley crops. The recent emergence of fungicide resistance imposes a need to develop new antifungal strategies. The enzymes involved in cell wall biosynthesis are ideal targets for the development of fungicides. However, in order to narrow down any target proteins involved in cell wall formation, a greater understanding of the cell wall structure and composition is required. Here, we present a detailed carbohydrate analysis of the Bgh conidial cell wall, a full annotation of Carbohydrate Active enZymes (CAZy) in the Bgh genome, and a comprehensive expression profile of the genes involved in cell wall metabolism. Glycosidic linkage analysis has revealed that the cell wall polysaccharide fraction of Bgh conidia predominantly consists of glucosyl residues (63.1%) and has a greater proportion of galactopyranosyl residues compared to other species (8.5%). Trace amounts of xylosyl residues were also detected, which is unusual in ascomycetes. Transcripts of the genes involved in cell wall metabolism show high expression of chitin deacetylases, which assist fungi in evading the host defence system by deacetylating chitin to chitosan. The data presented suggest that the cell wall components of the conidia and the corresponding obligate biotrophic CAZy gene profile play a key role in the infection process.
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Affiliation(s)
- Trang A.T. Pham
- ARC Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Bianca A. Kyriacou
- ARC Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Julian G. Schwerdt
- ARC Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Neil J. Shirley
- ARC Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Xiaohui Xing
- Adelaide Glycomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Vincent Bulone
- ARC Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
- Adelaide Glycomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Alan Little
- ARC Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
- Corresponding author.
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10
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Lee DJ, O'Donnell H, Routier FH, Tiralongo J, Haselhorst T. Glycobiology of Human Fungal Pathogens: New Avenues for Drug Development. Cells 2019; 8:cells8111348. [PMID: 31671548 PMCID: PMC6912366 DOI: 10.3390/cells8111348] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 12/20/2022] Open
Abstract
Invasive fungal infections (IFI) are an increasing threat to the developing world, with fungal spores being ubiquitous and inhaled every day. Some fungal species are commensal organisms that are part of the normal human microbiota, and, as such, do not pose a threat to the immune system. However, when the natural balance of this association is disturbed or the host's immune system is compromised, these fungal pathogens overtake the organism, and cause IFI. To understand the invasiveness of these pathogens and to address the growing problem of IFI, it is essential to identify the cellular processes of the invading organism and their virulence. In this review, we will discuss the prevalence and current options available to treat IFI, including recent reports of drug resistance. Nevertheless, the main focus of this review is to describe the glycobiology of human fungal pathogens and how various components of the fungal cell wall, particularly cell wall polysaccharides and glycoconjugates, are involved in fungal pathogenicity, their biosynthesis and how they can be potentially exploited to develop novel antifungal treatment options. We will specifically describe the nucleotide sugar transporters (NSTs) that are important in fungal survival and suggest that the inhibition of fungal NSTs may potentially be useful to prevent the establishment of fungal infections.
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Affiliation(s)
- Danielle J Lee
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia; Member of Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Nikolai-Fuchs Strasse 1, 30625 Hannover, Germany.
| | - Holly O'Donnell
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia; Member of Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Nikolai-Fuchs Strasse 1, 30625 Hannover, Germany.
| | - Françoise H Routier
- Department of Clinical Biochemistry OE4340, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany; Member of Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Nikolai-Fuchs Strasse 1, 30625 Hannover, Germany.
| | - Joe Tiralongo
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia; Member of Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Nikolai-Fuchs Strasse 1, 30625 Hannover, Germany.
| | - Thomas Haselhorst
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia; Member of Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Nikolai-Fuchs Strasse 1, 30625 Hannover, Germany.
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11
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Arentshorst M, de Lange D, Park J, Lagendijk EL, Alazi E, van den Hondel CAMJJ, Ram AFJ. Functional analysis of three putative galactofuranosyltransferases with redundant functions in galactofuranosylation in Aspergillus niger. Arch Microbiol 2019; 202:197-203. [PMID: 31372664 PMCID: PMC6949202 DOI: 10.1007/s00203-019-01709-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/05/2019] [Accepted: 07/20/2019] [Indexed: 10/27/2022]
Abstract
Galactofuranose (Galf)-containing glycostructures are important to secure the integrity of the fungal cell wall. Golgi-localized Galf-transferases (Gfs) have been identified in Aspergillus nidulans and Aspergillus fumigatus. BLASTp searches identified three putative Galf-transferases in Aspergillus niger. Phylogenetic analysis showed that they group in three distinct groups. Characterization of the three Galf-transferases in A. niger by constructing single, double, and triple mutants revealed that gfsA is most important for Galf biosynthesis. The growth phenotypes of the ΔgfsA mutant are less severe than that of the ΔgfsAC mutant, indicating that GfsA and GfsC have redundant functions. Deletion of gfsB did not result in any growth defect and combining ΔgfsB with other deletion mutants did not exacerbate the growth phenotype. RT-qPCR experiments showed that induction of the agsA gene was higher in the ΔgfsAC and ΔgfsABC compared to the single mutants, indicating a severe cell wall stress response after multiple gfs gene deletions.
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Affiliation(s)
- Mark Arentshorst
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Davina de Lange
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Joohae Park
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Ellen L Lagendijk
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.,Koppert Biological Systems, Veilingweg 14, 2651 BE, Berkel en Rodenrijs, The Netherlands
| | - Ebru Alazi
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.,Dutch DNA Biotech, Hugo R Kruytgebouw 4-Noord, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Cees A M J J van den Hondel
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Arthur F J Ram
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
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12
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Bakir G, Girouard BE, Johns RW, Findlay CRJ, Bechtel HA, Eisele M, Kaminskyj SGW, Dahms TES, Gough KM. Ultrastructural and SINS analysis of the cell wall integrity response of Aspergillus nidulans to the absence of galactofuranose. Analyst 2019; 144:928-934. [PMID: 30412213 DOI: 10.1039/c8an01591k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
With lethal opportunistic fungal infections on the rise, it is imperative to explore new methods to examine virulence mechanisms. The fungal cell wall is crucial for both the virulence and viability of Aspergillus nidulans. One wall component, Galf, has been shown to contribute to important fungal processes, integrity of the cell wall and pathogenesis. Here, we explore gene deletion strains lacking the penultimate enzyme in Galf biosynthesis (ugmAΔ) and the protein that transports Galf for incorporation into the cell wall (ugtAΔ). In applying gene deletion technology to the problem of cell wall integrity, we have employed multiple micro- and nano-scale imaging tools, including confocal fluorescence microscopy, electron microscopy, X-Ray fluorescence and atomic force microscopy. Atomic force microscopy allows quantification of ultrastructural cell wall architecture while near-field infrared spectroscopy provides spatially resolved chemical signatures, both at the nanoscale. Here, for the first time, we demonstrate correlative data collection with these two emerging modalities for the multiplexed in situ study of the nanoscale architecture and chemical composition of fungal cell walls.
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Affiliation(s)
- Görkem Bakir
- Department of Chemistry, University of Manitoba, R3 T 2N2, Winnipeg, Canada.
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13
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Ati J, Colas C, Lafite P, Sweeney RP, Zheng RB, Lowary TL, Daniellou R. The LPG1x family from Leishmania major is constituted of rare eukaryotic galactofuranosyltransferases with unprecedented catalytic properties. Sci Rep 2018; 8:17566. [PMID: 30514885 PMCID: PMC6279836 DOI: 10.1038/s41598-018-35847-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 11/09/2018] [Indexed: 12/15/2022] Open
Abstract
Galactofuranosyltransferases are poorly described enzymes despite their crucial role in the virulence and the pathogenicity of numerous microorganisms. These enzymes are considered as potential targets for therapeutic action. In addition to the only well-characterised prokaryotic GlfT2 from Mycobacterium tuberculosis, four putative genes in Leishmania major were previously described as potential galactofuranosyltransferases. In this study, we have cloned, over-expressed, purified and fully determined the kinetic parameters of these four eukaryotic enzymes, thus demonstrating their unique potency in catalysing the transfer of the galactofuranosyl moiety into acceptors. Their individual promiscuity revealed to be different, as some of them could efficiently use NDP-pyranoses as donor substrates in addition to the natural UDP-galactofuranose. Such results pave the way for the development of chemoenzymatic synthesis of furanosyl-containing glycoconjugates as well as the design of improved drugs against leishmaniasis.
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Affiliation(s)
- Jihen Ati
- Institut de Chimie Organique et Analytique, UMR CNRS 7311, Université d'Orléans, Rue de Chartres, BP6759, Orléans, Cedex 02, France
| | - Cyril Colas
- Institut de Chimie Organique et Analytique, UMR CNRS 7311, Université d'Orléans, Rue de Chartres, BP6759, Orléans, Cedex 02, France
| | - Pierre Lafite
- Institut de Chimie Organique et Analytique, UMR CNRS 7311, Université d'Orléans, Rue de Chartres, BP6759, Orléans, Cedex 02, France
| | - Ryan P Sweeney
- Alberta Glycomics Centre and Department of Chemistry, The University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Ruixiang Blake Zheng
- Alberta Glycomics Centre and Department of Chemistry, The University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Todd L Lowary
- Alberta Glycomics Centre and Department of Chemistry, The University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Richard Daniellou
- Institut de Chimie Organique et Analytique, UMR CNRS 7311, Université d'Orléans, Rue de Chartres, BP6759, Orléans, Cedex 02, France.
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14
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Kadry AA, El-Ganiny AM, Mosbah RA, Kaminskyj SGW. Deletion of Aspergillus nidulans GDP-mannose transporters affects hyphal morphometry, cell wall architecture, spore surface character, cell adhesion, and biofilm formation. Med Mycol 2018; 56:621-630. [PMID: 29420778 DOI: 10.1093/mmy/myx082] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 08/24/2017] [Indexed: 02/06/2023] Open
Abstract
Systemic human fungal infections are increasingly common. Aspergillus species cause most of the airborne fungal infections. Life-threatening invasive aspergillosis was formerly found only in immune-suppressed patients, but recently some strains of A. fumigatus have become primary pathogens. Many fungal cell wall components are absent from mammalian systems, so they are potential drug targets. Cell-wall-targeting drugs such as echinocandins are used clinically, although echinocandin-resistant strains were discovered shortly after their introduction. Currently there are no fully effective anti-fungal drugs. Fungal cell wall glycoconjugates modulate human immune responses, as well as fungal cell adhesion, biofilm formation, and drug resistance. Guanosine diphosphate (GDP) mannose transporters (GMTs) transfer GDP-mannose from the cytosol to the Golgi lumen prior to mannosylation. Aspergillus nidulans GMTs are encoded by gmtA and gmtB. Here we elucidate the roles of A. nidulans GMTs. Strains engineered to lack either or both GMTs were assessed for hyphal and colonial morphology, cell wall ultrastructure, antifungal susceptibility, spore hydrophobicity, adherence and biofilm formation. The gmt-deleted strains had smaller colonies with reduced sporulation and with thicker hyphal walls. The gmtA deficient spores had reduced hydrophobicity and were less adherent and less able to form biofilms in vitro. Thus, gmtA not only participates in maintaining the cell wall integrity but also plays an important role in biofilm establishment and adherence of A. nidulans. These findings suggested that GMTs have roles in A. nidulans growth and cell-cell interaction and could be a potential target for new antifungals that target virulence determinants.
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Affiliation(s)
- Ashraf A Kadry
- Microbiology and Immunology Department, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt
| | - Amira M El-Ganiny
- Microbiology and Immunology Department, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt
| | - Rasha A Mosbah
- Microbiology and Immunology Department, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt.,Zagazig University Hospitals, Zagazig, Egypt
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15
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Amino Acid Metabolism and Transport Mechanisms as Potential Antifungal Targets. Int J Mol Sci 2018; 19:ijms19030909. [PMID: 29562716 PMCID: PMC5877770 DOI: 10.3390/ijms19030909] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/13/2018] [Accepted: 03/15/2018] [Indexed: 01/15/2023] Open
Abstract
Discovering new drugs for treatment of invasive fungal infections is an enduring challenge. There are only three major classes of antifungal agents, and no new class has been introduced into clinical practice in more than a decade. However, recent advances in our understanding of the fungal life cycle, functional genomics, proteomics, and gene mapping have enabled the identification of new drug targets to treat these potentially deadly infections. In this paper, we examine amino acid transport mechanisms and metabolism as potential drug targets to treat invasive fungal infections, including pathogenic yeasts, such as species of Candida and Cryptococcus, as well as molds, such as Aspergillus fumigatus. We also explore the mechanisms by which amino acids may be exploited to identify novel drug targets and review potential hurdles to bringing this approach into clinical practice.
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16
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Oka T. Biosynthesis of galactomannans found in filamentous fungi belonging to Pezizomycotina. Biosci Biotechnol Biochem 2018; 82:183-191. [PMID: 29334321 DOI: 10.1080/09168451.2017.1422383] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The galactomannans (GMs) that are produced by filamentous fungi belonging to Pezizomycotina, many of which are pathogenic for animals and plants, are polysaccharides consisting of α-(1→2)-/α-(1→6)-mannosyl and β-(1→5)-/β-(1→6)-galactofuranosyl residues. GMs are located at the outermost layer of the cell wall. When a pathogenic fungus infects a host, its cell surface must be in contact with the host. The GMs on the cell surface may be involved in the infection mechanism of a pathogenic fungus or the defense mechanism of a host. There are two types of GMs in filamentous fungi, fungal-type galactomannans and O-mannose type galactomannans. Recent biochemical and genetic advances have facilitated a better understanding of the biosynthesis of both types. This review summarizes our current information on their biosynthesis.
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Affiliation(s)
- Takuji Oka
- a Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science , Sojo University , Kumamoto , Japan
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17
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Matsunaga E, Higuchi Y, Mori K, Yairo N, Toyota S, Oka T, Tashiro K, Takegawa K. Characterization of a PA14 domain-containing galactofuranose-specific β-d-galactofuranosidase from Streptomyces sp. Biosci Biotechnol Biochem 2017; 81:1314-1319. [DOI: 10.1080/09168451.2017.1300518] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
As a constituent of polysaccharides and glycoconjugates, β-d-galactofuranose (Galf) exists in several pathogenic microorganisms. Although we recently identified a β-d-galactofuranosidase (Galf-ase) gene, ORF1110, in the Streptomyces strain JHA19, very little is known about the Galf-ase gene. Here, we characterized a strain, named JHA26, in the culture supernatant of which exhibited Galf-ase activity for 4-nitrophenyl β-d-galactofuranoside (pNP-β-d-Galf) as a substrate. Draft genome sequencing of the JHA26 strain revealed a putative gene, termed ORF0643, that encodes Galf-ase containing a PA14 domain, which is thought to function in substrate recognition. The recombinant protein expressed in Escherichia coli showed the Galf-specific Galf-ase activity and also released galactose residue of the polysaccharide galactomannan prepared from Aspergillus fumigatus, suggesting that this enzyme is an exo-type Galf-ase. BLAST searches using the amino acid sequences of ORF0643 and ORF1110 Galf-ases revealed two types of Galf-ases in Actinobacteria, suggesting that Galf-specific Galf-ases may exhibit discrete substrate specificities.
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Affiliation(s)
- Emiko Matsunaga
- Faculty of Agriculture, Department of Bioscience and Biotechnology, Kyushu University, Fukuoka, Japan
| | - Yujiro Higuchi
- Faculty of Agriculture, Department of Bioscience and Biotechnology, Kyushu University, Fukuoka, Japan
| | - Kazuki Mori
- Faculty of Agriculture, Department of Bioscience and Biotechnology, Kyushu University, Fukuoka, Japan
| | - Nao Yairo
- Faculty of Agriculture, Department of Bioscience and Biotechnology, Kyushu University, Fukuoka, Japan
| | - Saki Toyota
- Faculty of Agriculture, Department of Bioscience and Biotechnology, Kyushu University, Fukuoka, Japan
| | - Takuji Oka
- Faculty of Biotechnology and Life Science, Department of Applied Microbial Technology, Sojo University, Kumamoto, Japan
| | - Kosuke Tashiro
- Faculty of Agriculture, Department of Bioscience and Biotechnology, Kyushu University, Fukuoka, Japan
| | - Kaoru Takegawa
- Faculty of Agriculture, Department of Bioscience and Biotechnology, Kyushu University, Fukuoka, Japan
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18
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Katafuchi Y, Li Q, Tanaka Y, Shinozuka S, Kawamitsu Y, Izumi M, Ekino K, Mizuki K, Takegawa K, Shibata N, Goto M, Nomura Y, Ohta K, Oka T. GfsA is a β1,5-galactofuranosyltransferase involved in the biosynthesis of the galactofuran side chain of fungal-type galactomannan in Aspergillus fumigatus. Glycobiology 2017; 27:568-581. [DOI: 10.1093/glycob/cwx028] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 03/24/2017] [Indexed: 01/01/2023] Open
Affiliation(s)
- Yukako Katafuchi
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Ikeda 4-22-1, Kumamoto 860-0082, Japan
| | - Qiushi Li
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Ikeda 4-22-1, Kumamoto 860-0082, Japan
| | - Yutaka Tanaka
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, Komatsushima 4-4-1, Sendai 981-8558, Japan
| | - Saki Shinozuka
- Graduate School of Environmental and Life Science, Okayama University, Tsushimanaka 1-1-1, Okayama 700-8530, Japan
| | - Yohei Kawamitsu
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Ikeda 4-22-1, Kumamoto 860-0082, Japan
| | - Minoru Izumi
- Graduate School of Environmental and Life Science, Okayama University, Tsushimanaka 1-1-1, Okayama 700-8530, Japan
| | - Keisuke Ekino
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Ikeda 4-22-1, Kumamoto 860-0082, Japan
| | - Keiji Mizuki
- Department of Nanoscience, Faculty of Engineering, Sojo University, Ikeda 4-22-1, Kumamoto 860-0082, Japan
| | - Kaoru Takegawa
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan
| | - Nobuyuki Shibata
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, Komatsushima 4-4-1, Sendai 981-8558, Japan
| | - Masatoshi Goto
- Department of Applied Biochemistry and Food Science, Saga University, Honjo-machi 1, Saga 840-8502, Japan
| | - Yoshiyuki Nomura
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Ikeda 4-22-1, Kumamoto 860-0082, Japan
| | - Kazuyoshi Ohta
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Ikeda 4-22-1, Kumamoto 860-0082, Japan
| | - Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Ikeda 4-22-1, Kumamoto 860-0082, Japan
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19
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Park J, Hulsman M, Arentshorst M, Breeman M, Alazi E, Lagendijk EL, Rocha MC, Malavazi I, Nitsche BM, van den Hondel CAMJJ, Meyer V, Ram AFJ. Transcriptomic and molecular genetic analysis of the cell wall salvage response of Aspergillus niger to the absence of galactofuranose synthesis. Cell Microbiol 2016; 18:1268-84. [PMID: 27264789 PMCID: PMC5129474 DOI: 10.1111/cmi.12624] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 05/16/2016] [Accepted: 05/30/2016] [Indexed: 12/11/2022]
Abstract
The biosynthesis of cell surface-located galactofuranose (Galf)-containing glycostructures such as galactomannan, N-glycans and O-glycans in filamentous fungi is important to secure the integrity of the cell wall. UgmA encodes an UDP-galactopyranose mutase, which is essential for the formation of Galf. Consequently, the ΔugmA mutant lacks Galf-containing molecules. Our previous work in Aspergillus niger work suggested that loss of function of ugmA results in activation of the cell wall integrity (CWI) pathway which is characterized by increased expression of the agsA gene, encoding an α-glucan synthase. In this study, the transcriptional response of the ΔugmA mutant was further linked to the CWI pathway by showing the induced and constitutive phosphorylation of the CWI-MAP kinase in the ΔugmA mutant. To identify genes involved in cell wall remodelling in response to the absence of galactofuranose biosynthesis, a genome-wide expression analysis was performed using RNAseq. Over 400 genes were higher expressed in the ΔugmA mutant compared to the wild-type. These include genes that encode enzymes involved in chitin (gfaB, gnsA, chsA) and α-glucan synthesis (agsA), and in β-glucan remodelling (bgxA, gelF and dfgC), and also include several glycosylphosphatidylinositol (GPI)-anchored cell wall protein-encoding genes. In silico analysis of the 1-kb promoter regions of the up-regulated genes in the ΔugmA mutant indicated overrepresentation of genes with RlmA, MsnA, PacC and SteA-binding sites. The importance of these transcription factors for survival of the ΔugmA mutant was analysed by constructing the respective double mutants. The ΔugmA/ΔrlmA and ΔugmA/ΔmsnA double mutants showed strong synthetic growth defects, indicating the importance of these transcription factors to maintain cell wall integrity in the absence of Galf biosynthesis.
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Affiliation(s)
- Joohae Park
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Mark Hulsman
- Delft Bioinformatics Lab, Department of Intelligent Systems, Faculty Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, Mekelweg 4, 2628 CD, Delft, The Netherlands
| | - Mark Arentshorst
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Matthijs Breeman
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Ebru Alazi
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Ellen L Lagendijk
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Marina C Rocha
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Paulo, Brazil
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Paulo, Brazil
| | - Benjamin M Nitsche
- Applied and Molecular Microbiology, Institute of Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, 13355, Berlin, Germany
| | - Cees A M J J van den Hondel
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Vera Meyer
- Applied and Molecular Microbiology, Institute of Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, 13355, Berlin, Germany
| | - Arthur F J Ram
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
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20
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Orellana A, Moraga C, Araya M, Moreno A. Overview of Nucleotide Sugar Transporter Gene Family Functions Across Multiple Species. J Mol Biol 2016; 428:3150-3165. [PMID: 27261257 DOI: 10.1016/j.jmb.2016.05.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/19/2016] [Accepted: 05/23/2016] [Indexed: 11/16/2022]
Abstract
Glycoproteins and glycolipids are crucial in a number of cellular processes, such as growth, development, and responses to external cues, among others. Polysaccharides, another class of sugar-containing molecules, also play important structural and signaling roles in the extracellular matrix. The additions of glycans to proteins and lipids, as well as polysaccharide synthesis, are processes that primarily occur in the Golgi apparatus, and the substrates used in this biosynthetic process are nucleotide sugars. These proteins, lipids, and polysaccharides are also modified by the addition of sulfate groups in the Golgi apparatus in a series of reactions where nucleotide sulfate is needed. The required nucleotide sugar substrates are mainly synthesized in the cytosol and transported into the Golgi apparatus by nucleotide sugar transporters (NSTs), which can additionally transport nucleotide sulfate. Due to the critical role of NSTs in eukaryotic organisms, any malfunction of these could change glycan and polysaccharide structures, thus affecting function and altering organism physiology. For example, mutations or deletion on NST genes lead to pathological conditions in humans or alter cell walls in plants. In recent years, many NSTs have been identified and functionally characterized, but several remain unanalyzed. This study examined existing information on functionally characterized NSTs and conducted a phylogenetic analysis of 257 NSTs predicted from nine animal and plant model species, as well as from protists and fungi. From this analysis, relationships between substrate specificity and the primary NST structure can be inferred, thereby advancing understandings of nucleotide sugar gene family functions across multiple species.
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Affiliation(s)
- Ariel Orellana
- Centro de Biotecnología Vegetal, Universidad Andres Bello, Av. República 217, Santiago, RM 837-0146, Chile; FONDAP Center for Genome Regulation, Santiago, RM,Chile.
| | - Carol Moraga
- Centro de Biotecnología Vegetal, Universidad Andres Bello, Av. República 217, Santiago, RM 837-0146, Chile.
| | - Macarena Araya
- Centro de Biotecnología Vegetal, Universidad Andres Bello, Av. República 217, Santiago, RM 837-0146, Chile.
| | - Adrian Moreno
- Centro de Biotecnología Vegetal, Universidad Andres Bello, Av. República 217, Santiago, RM 837-0146, Chile; FONDAP Center for Genome Regulation, Santiago, RM,Chile.
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21
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Oka T, Goto M. Biosynthesis of Galactofuranose-containing Glycans in Filamentous Fungi. TRENDS GLYCOSCI GLYC 2016. [DOI: 10.4052/tigg.1428.1j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo, University
| | - Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University
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22
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Oka T, Goto M. Biosynthesis of Galactofuranose-containing Glycans in Filamentous Fungi. TRENDS GLYCOSCI GLYC 2016. [DOI: 10.4052/tigg.1428.1e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo, University
| | - Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University
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23
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Park J, Tefsen B, Heemskerk MJ, Lagendijk EL, van den Hondel CAMJJ, van Die I, Ram AFJ. Identification and functional analysis of two Golgi-localized UDP-galactofuranose transporters with overlapping functions in Aspergillus niger. BMC Microbiol 2015; 15:253. [PMID: 26526354 PMCID: PMC4630932 DOI: 10.1186/s12866-015-0541-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 09/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Galactofuranose (Galf)-containing glycoconjugates are present in numerous microbes, including filamentous fungi where they are important for morphology, virulence and maintaining cell wall integrity. The incorporation of Galf-residues into galactomannan, galactomannoproteins and glycolipids is carried out by Golgi-localized Galf transferases. The nucleotide sugar donor used by these transferases (UDP-Galf) is produced in the cytoplasm and has to be transported to the lumen of the Golgi by a dedicated nucleotide sugar transporter. METHODS Based on homology with recently identified UDP-Galf-transporters in A. fumigatus and A. nidulans, two putative UDP-Galf-transporters in A. niger were found. Their function and localization was determined by gene deletions and GFP-tagging studies, respectively. RESULTS The two putative UDP-Galf-transporters in A. niger are homologous to each other and are predicted to contain eleven transmembrane domains (UgtA) or ten transmembrane domains (UgtB) due to a reduced length of the C-terminal part of the UgtB protein. The presence of two putative UDP-Galf-transporters in the genome was not unique for A. niger. From the twenty Aspergillus species analysed, nine species contained two additional putative UDP-Galf-transporters. Three of the nine species were outside the Aspergillus section nigri, indication an early duplication of UDP-Galf-transporters and subsequent loss of the UgtB copy in several aspergilli. Deletion analysis of the single and double mutants in A. niger indicated that the two putative UDP-Galf-transporters (named UgtA and UgtB) have a redundant function in UDP-Galf-transport as only the double mutant displayed a Galf-negative phenotype. The Galf-negative phenotype of the double mutant could be complemented by expressing either CFP-UgtA or CFP-UgtB fusion proteins from their endogenous promoters, indicating that both CFP-tagged proteins are functional. Both Ugt proteins co-localize with each other as well as with the GDP-mannose nucleotide transporter, as was demonstrated by fluorescence microscopy, thereby confirming their predicted localization in the Golgi. CONCLUSION A. niger contains two genes encoding UDP-Galf-transporters. Deletion and localization studies indicate that UgtA and UgtB have redundant functions in the biosynthesis of Galf-containing glycoconjugates.
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Affiliation(s)
- Joohae Park
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
| | - Boris Tefsen
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, van den Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands. .,Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren Ai Road, Dushu Lake Higher Education Town, Suzhou Industrial Park, Suzhou, Jiangsu, 215123, China.
| | - Marc J Heemskerk
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
| | - Ellen L Lagendijk
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
| | - Cees A M J J van den Hondel
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
| | - Irma van Die
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, van den Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
| | - Arthur F J Ram
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
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Identification and Characterization of a Novel Galactofuranose-Specific β-D-Galactofuranosidase from Streptomyces Species. PLoS One 2015; 10:e0137230. [PMID: 26340350 PMCID: PMC4560423 DOI: 10.1371/journal.pone.0137230] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/14/2015] [Indexed: 12/02/2022] Open
Abstract
β-D-galactofuranose (Galf) is a component of polysaccharides and glycoconjugates and its transferase has been well analyzed. However, no β-D-galactofuranosidase (Galf-ase) gene has been identified in any organism. To search for a Galf-ase gene we screened soil samples and discovered a strain, identified as a Streptomyces species by the 16S ribosomal RNA gene analysis, that exhibits Galf-ase activity for 4-nitrophenyl β-D-galactofuranoside (pNP-β-D-Galf) in culture supernatants. By draft genome sequencing of the strain, named JHA19, we found four candidate genes encoding Galf-ases. Using recombinant proteins expressed in Escherichia coli, we found that three out of four candidates displayed the activity of not only Galf-ase but also α-L-arabinofuranosidase (Araf-ase), whereas the other one showed only the Galf-ase activity. This novel Galf-specific hydrolase is encoded by ORF1110 and has an optimum pH of 5.5 and a Km of 4.4 mM for the substrate pNP-β-D-Galf. In addition, this enzyme was able to release galactose residue from galactomannan prepared from the filamentous fungus Aspergillus fumigatus, suggesting that natural polysaccharides could be also substrates. By the BLAST search using the amino acid sequence of ORF1110 Galf-ase, we found that there are homolog genes in both prokaryotes and eukaryotes, indicating that Galf-specific Galf-ases widely exist in microorganisms.
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Li M, Chen T, Gao T, Miao Z, Jiang A, Shi L, Ren A, Zhao M. UDP-glucose pyrophosphorylase influences polysaccharide synthesis, cell wall components, and hyphal branching in Ganoderma lucidum via regulation of the balance between glucose-1-phosphate and UDP-glucose. Fungal Genet Biol 2015; 82:251-63. [PMID: 26235043 DOI: 10.1016/j.fgb.2015.07.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/29/2015] [Accepted: 07/30/2015] [Indexed: 01/12/2023]
Abstract
UDP-glucose pyrophosphorylase (UGP) is a key enzyme involved in carbohydrate metabolism, but there are few studies on the functions of this enzyme in fungi. The ugp gene of Ganoderma lucidum was cloned, and enzyme kinetic parameters of the UGP recombinant protein were determined in vitro, revealing that this protein was functional and catalyzed the reversible conversion between Glc-1-P and UDP-Glc. ugp silencing by RNA interference resulted in changes in the levels of the intermediate metabolites Glc-1-P and UDP-Glc. The compounds and structure of the cell wall in the silenced strains were also altered compared with those in the wild-type strains. Moreover, the number of hyphal branches was also changed in the silenced strains. To verify the role of UGP in hyphal branching, a ugp-overexpressing strain was constructed. The results showed that the number of hyphal branches was influenced by UGP. The mechanism underlying hyphal branching was further investigated by adding exogenous Glc-1-P. Our results showed that hyphal branching was regulated by a change in the cytosolic Ca(2+) concentration, which was affected by the level of the intermediate metabolite Glc-1-P, in G. lucidum. Our findings indicate the existence of an interaction between carbon metabolism and Ca(2+) signaling in this fungus.
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Affiliation(s)
- Mengjiao Li
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing 210095, Jiangsu, People's Republic of China
| | - Tianxi Chen
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing 210095, Jiangsu, People's Republic of China
| | - Tan Gao
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing 210095, Jiangsu, People's Republic of China
| | - Zhigang Miao
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing 210095, Jiangsu, People's Republic of China
| | - Ailiang Jiang
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing 210095, Jiangsu, People's Republic of China
| | - Liang Shi
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing 210095, Jiangsu, People's Republic of China
| | - Ang Ren
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing 210095, Jiangsu, People's Republic of China
| | - Mingwen Zhao
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing 210095, Jiangsu, People's Republic of China.
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Park J, Tefsen B, Arentshorst M, Lagendijk E, van den Hondel CA, van Die I, Ram AF. Identification of the UDP-glucose-4-epimerase required for galactofuranose biosynthesis and galactose metabolism in A. niger. Fungal Biol Biotechnol 2014; 1:6. [PMID: 28955448 PMCID: PMC5598270 DOI: 10.1186/s40694-014-0006-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 09/01/2014] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Galactofuranose (Galf)-containing glycoconjugates are important to secure the integrity of the cell wall of filamentous fungi. Mutations that prevent the biosynthesis of Galf-containing molecules compromise cell wall integrity. In response to cell wall weakening, the cell wall integrity (CWI)-pathway is activated to reinforce the strength of the cell wall. Activation of CWI-pathway in Aspergillus niger is characterized by the specific induction of the agsA gene, which encodes a cell wall α-glucan synthase. RESULTS In this study, we screened a collection of cell wall mutants with an induced expression of agsA for defects in Galf biosynthesis using a with anti-Galf antibody (L10). From this collection of mutants, we previously identified mutants in the UDP-galactopyranose mutase encoding gene (ugmA). Here, we have identified six additional UDP-galactopyranose mutase (ugmA) mutants and one mutant (named mutant #41) in an additional complementation group that displayed strongly reduced Galf-levels in the cell wall. By using a whole genome sequencing approach, 21 SNPs in coding regions were identified between mutant #41 and its parental strain which changed the amino acid sequence of the encoded proteins. One of these mutations was in gene An14g03820, which codes for a putative UDP-glucose-4-epimerase (UgeA). The A to G mutation in this gene causes an amino acid change of Asn to Asp at position 191 in the UgeA protein. Targeted deletion of ugeA resulted in an even more severe reduction of Galf in N-linked glucans, indicating that the UgeA protein in mutant #41 is partially active. The ugeA gene is also required for growth on galactose despite the presence of two UgeA homologs in the A. niger genome. CONCLUSION By using a classical mutant screen and whole genome sequencing of a new Galf-deficient mutant, the UDP-glucose-4-epimerase gene (ugeA) has been identified. UgeA is required for the biosynthesis of Galf as well as for galactose metabolism in Aspergillus niger.
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Affiliation(s)
- Joohae Park
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, Leiden, 2333 BE The Netherlands
| | - Boris Tefsen
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, van den Boechorststraat 7, Amsterdam, 1081 BT The Netherlands.,Present Address: Department of Biological Sciences, Xi'an Jiaotong Liverpool University, 111 Ren Ai Road, Dushu Lake Higher Education Town, Suzhou Industrial Park, Suzhou, 215123 Jiangsu, China
| | - Mark Arentshorst
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, Leiden, 2333 BE The Netherlands
| | - Ellen Lagendijk
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, Leiden, 2333 BE The Netherlands
| | - Cees Amjj van den Hondel
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, Leiden, 2333 BE The Netherlands
| | - Irma van Die
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, van den Boechorststraat 7, Amsterdam, 1081 BT The Netherlands
| | - Arthur Fj Ram
- Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, Leiden, 2333 BE The Netherlands
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Alam MK, van Straaten KE, Sanders DAR, Kaminskyj SGW. Aspergillus nidulans cell wall composition and function change in response to hosting several Aspergillus fumigatus UDP-galactopyranose mutase activity mutants. PLoS One 2014; 9:e85735. [PMID: 24454924 PMCID: PMC3893270 DOI: 10.1371/journal.pone.0085735] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 11/30/2013] [Indexed: 11/18/2022] Open
Abstract
Deletion or repression of Aspergillus nidulans ugmA (AnugmA), involved in galactofuranose biosynthesis, impairs growth and increases sensitivity to Caspofungin, a β-1,3-glucan synthesis antagonist. The A. fumigatus UgmA (AfUgmA) crystal structure has been determined. From that study, AfUgmA mutants with altered enzyme activity were transformed into AnugmA▵ to assess their effect on growth and wall composition in A. nidulans. The complemented (AnugmA::wild type AfugmA) strain had wild type phenotype, indicating these genes had functional homology. Consistent with in vitro studies, AfUgmA residues R182 and R327 were important for its function in vivo, with even conservative amino (RK) substitutions producing AnugmA? phenotype strains. Similarly, the conserved AfUgmA loop III histidine (H63) was important for Galf generation: the H63N strain had a partially rescued phenotype compared to AnugmA▵. Collectively, A. nidulans strains that hosted mutated AfUgmA constructs with low enzyme activity showed increased hyphal surface adhesion as assessed by binding fluorescent latex beads. Consistent with previous qPCR results, immunofluorescence and ELISA indicated that AnugmA▵ and AfugmA-mutated A. nidulans strains had increased α-glucan and decreased β-glucan in their cell walls compared to wild type and AfugmA-complemented strains. Like the AnugmA▵ strain, A. nidulans strains containing mutated AfugmA showed increased sensitivity to antifungal drugs, particularly Caspofungin. Reduced β-glucan content was correlated with increased Caspofungin sensitivity. Aspergillus nidulans wall Galf, α-glucan, and β-glucan content was correlated in A. nidulans hyphal walls, suggesting dynamic coordination between cell wall synthesis and cell wall integrity.
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Affiliation(s)
- Md Kausar Alam
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- * E-mail:
| | - Karin E. van Straaten
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - David A. R. Sanders
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Komachi Y, Hatakeyama S, Motomatsu H, Futagami T, Kizjakina K, Sobrado P, Ekino K, Takegawa K, Goto M, Nomura Y, Oka T. GfsA encodes a novel galactofuranosyltransferase involved in biosynthesis of galactofuranose antigen of O-glycan in Aspergillus nidulans and Aspergillus fumigatus. Mol Microbiol 2013; 90:1054-1073. [PMID: 24118544 PMCID: PMC3907285 DOI: 10.1111/mmi.12416] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2013] [Indexed: 11/30/2022]
Abstract
The cells walls of filamentous fungi in the genus Aspergillus have galactofuranose (Galf)-containing polysaccharides and glycoconjugates, including O-glycans, N-glycans, fungal-type galactomannan and glycosylinositolphosphoceramide, which are important for cell wall integrity. Here, we attempted to identify galactofuranosyltransferases that couple Galf monomers onto other wall components in Aspergillus nidulans. Using reverse-genetic and biochemical approaches, we identified that the AN8677 gene encoded a galactofuranosyltransferase, which we called GfsA, involved in Galf antigen biosynthesis. Disruption of gfsA reduced binding of β-Galf-specific antibody EB-A2 to O-glycosylated WscA protein and galactomannoproteins. The results of an in-vitro Galf antigen synthase assay revealed that GfsA has β1,5- or β1,6-galactofuranosyltransferase activity for O-glycans in glycoproteins, uses UDP-d-Galf as a sugar donor, and requires a divalent manganese cation for activity. GfsA was found to be localized at the Golgi apparatus based on cellular fractionation experiments. ΔgfsA cells exhibited an abnormal morphology characterized by poor hyphal extension, hyphal curvature and limited formation of conidia. Several gfsA orthologues were identified in members of the Pezizomycotina subphylum of Ascomycota, including the human pathogen Aspergillus fumigatus. To our knowledge, this is the first characterization of a fungal β-galactofuranosyltransferase, which was shown to be involved in Galf antigen biosynthesis of O-glycans in the Golgi.
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Affiliation(s)
- Yuji Komachi
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Kumamoto, Japan
| | - Shintaro Hatakeyama
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Kumamoto, Japan
| | - Haruka Motomatsu
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Kumamoto, Japan
| | - Taiki Futagami
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Karina Kizjakina
- Department of Biochemistry, Virginia Tech Blacksburg, VA, United States
| | - Pablo Sobrado
- Department of Biochemistry, Virginia Tech Blacksburg, VA, United States
| | - Keisuke Ekino
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Kumamoto, Japan
| | - Kaoru Takegawa
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Yoshiyuki Nomura
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Kumamoto, Japan
| | - Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Kumamoto, Japan
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Lee MJ, Gravelat FN, Cerone RP, Baptista SD, Campoli PV, Choe SI, Kravtsov I, Vinogradov E, Creuzenet C, Liu H, Berghuis AM, Latgé JP, Filler SG, Fontaine T, Sheppard DC. Overlapping and distinct roles of Aspergillus fumigatus UDP-glucose 4-epimerases in galactose metabolism and the synthesis of galactose-containing cell wall polysaccharides. J Biol Chem 2013; 289:1243-56. [PMID: 24257745 DOI: 10.1074/jbc.m113.522516] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The cell wall of Aspergillus fumigatus contains two galactose-containing polysaccharides, galactomannan and galactosaminogalactan, whose biosynthetic pathways are not well understood. The A. fumigatus genome contains three genes encoding putative UDP-glucose 4-epimerases, uge3, uge4, and uge5. We undertook this study to elucidate the function of these epimerases. We found that uge4 is minimally expressed and is not required for the synthesis of galactose-containing exopolysaccharides or galactose metabolism. Uge5 is the dominant UDP-glucose 4-epimerase in A. fumigatus and is essential for normal growth in galactose-based medium. Uge5 is required for synthesis of the galactofuranose (Galf) component of galactomannan and contributes galactose to the synthesis of galactosaminogalactan. Uge3 can mediate production of both UDP-galactose and UDP-N-acetylgalactosamine (GalNAc) and is required for the production of galactosaminogalactan but not galactomannan. In the absence of Uge5, Uge3 activity is sufficient for growth on galactose and the synthesis of galactosaminogalactan containing lower levels of galactose but not the synthesis of Galf. A double deletion of uge5 and uge3 blocked growth on galactose and synthesis of both Galf and galactosaminogalactan. This study is the first survey of glucose epimerases in A. fumigatus and contributes to our understanding of the role of these enzymes in metabolism and cell wall synthesis.
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Affiliation(s)
- Mark J Lee
- From the Department of Microbiology and Immunology, McGill University, Montréal, Québec H3A 2B4, Canada
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Engel J, Schmalhorst PS, Routier FH. Biosynthesis of the fungal cell wall polysaccharide galactomannan requires intraluminal GDP-mannose. J Biol Chem 2012; 287:44418-24. [PMID: 23139423 DOI: 10.1074/jbc.m112.398321] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Fungal cell walls frequently contain a polymer of mannose and galactose called galactomannan. In the pathogenic filamentous fungus Aspergillus fumigatus, this polysaccharide is made of a linear mannan backbone with side chains of galactofuran and is anchored to the plasma membrane via a glycosylphosphatidylinositol or is covalently linked to the cell wall. To date, the biosynthesis and significance of this polysaccharide are unknown. The present data demonstrate that deletion of the Golgi UDP-galactofuranose transporter GlfB or the GDP-mannose transporter GmtA leads to the absence of galactofuran or galactomannan, respectively. This indicates that the biosynthesis of galactomannan probably occurs in the lumen of the Golgi apparatus and thus contrasts with the biosynthesis of other fungal cell wall polysaccharides studied to date that takes place at the plasma membrane. Transglycosylation of galactomannan from the membrane to the cell wall is hypothesized because both the cell wall-bound and membrane-bound polysaccharide forms are affected in the generated mutants. Considering the severe growth defect of the A. fumigatus GmtA-deficient mutant, proving this paradigm might provide new targets for antifungal therapy.
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Affiliation(s)
- Jakob Engel
- Department of Cellular Chemistry, OE 4330, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
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31
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Alam MK, El-Ganiny AM, Afroz S, Sanders DAR, Liu J, Kaminskyj SGW. Aspergillus nidulans galactofuranose biosynthesis affects antifungal drug sensitivity. Fungal Genet Biol 2012; 49:1033-43. [PMID: 23078837 DOI: 10.1016/j.fgb.2012.08.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 07/17/2012] [Accepted: 08/14/2012] [Indexed: 12/30/2022]
Abstract
The cell wall is essential for fungal survival in natural environments. Many fungal wall carbohydrates are absent from humans, so they are a promising source of antifungal drug targets. Galactofuranose (Galf) is a sugar that decorates certain carbohydrates and lipids. It comprises about 5% of the Aspergillus fumigatus cell wall, and may play a role in systemic aspergillosis. We are studying Aspergillus wall formation in the tractable model system, A. nidulans. Previously we showed single-gene deletions of three sequential A. nidulans Galf biosynthesis proteins each caused similar hyphal morphogenesis defects and 500-fold reduced colony growth and sporulation. Here, we generated ugeA, ugmA and ugtA strains controlled by the alcA(p) or niiA(p) regulatable promoters. For repression and expression, alcA(p)-regulated strains were grown on complete medium with glucose or threonine, whereas niiA(p)-regulated strains were grown on minimal medium with ammonium or nitrate. Expression was assessed by qPCR and colony phenotype. The alcA(p) and niiA(p) strains produced similar effects: colonies resembling wild type for gene expression, and resembling deletion strains for gene repression. Galf immunolocalization using the L10 monoclonal antibody showed that ugmA deletion and repression phenotypes correlated with loss of hyphal wall Galf. None of the gene manipulations affected itraconazole sensitivity, as expected. Deletion of any of ugmA, ugeA, ugtA, their repression by alcA(p) or niiA(p), OR, ugmA overexpression by alcA(p), increased sensitivity to Caspofungin. Strains with alcA(p)-mediated overexpression of ugeA and ugtA had lower caspofungin sensitivity. Galf appears to play an important role in A. nidulans growth and vigor.
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Affiliation(s)
- Md Kausar Alam
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, Canada S7N 5E2
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Wang S, Cao J, Liu X, Hu H, Shi J, Zhang S, Keller NP, Lu L. Putative calcium channels CchA and MidA play the important roles in conidiation, hyphal polarity and cell wall components in Aspergillus nidulans. PLoS One 2012; 7:e46564. [PMID: 23071589 PMCID: PMC3470553 DOI: 10.1371/journal.pone.0046564] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 08/31/2012] [Indexed: 11/25/2022] Open
Abstract
Although the high affinity Ca2+ channel, Cch1, and its subunit Mid1 have been investigated and evaluated in yeast and some of filamentous fungi, little is known about the function of their homologs in the Aspergilli. Here, we have functionally characterized the yeast homologs, CchA and MidA, in Aspergillus nidulans using conditional and null deletion mutants. CchA and MidA not only have functional benefits of fast growth, which is consistent with Cch1 and Mid1 in yeast, but also have unique and complex roles in regulating conidiation, hyphal polarity and cell wall components in low-calcium environments. The defect of CchA or MidA resulted in a sharp reduction in the number of conidiospores, accompanied by abnormal metulae, and undeveloped-phialides at a higher density of inoculum. Most interestingly, these conidiation defects in mutants can, remarkably, be rescued either by extra-cellular Ca2+ in a calcineurin-dependent way or by osmotic stress in a calcineurin-independent way. Moreover, the fact that the phenotypic defects are not exacerbated by the presence of the double deletion, together with the Y2H assay, indicates that CchA and MidA may form a complex to function together. Our findings suggest that the high-affinity Ca2+ channel may represent a viable and completely unexplored avenue to reduce conidiation in the Aspergilli.
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Affiliation(s)
- Sha Wang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences; Nanjing Normal University, Nanjing, China
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Prusinkiewicz MA, Farazkhorasani F, Dynes JJ, Wang J, Gough KM, Kaminskyj SGW. Proof-of-principle for SERS imaging of Aspergillus nidulans hyphae using in vivo synthesis of gold nanoparticles. Analyst 2012; 137:4934-42. [DOI: 10.1039/c2an35620a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tefsen B, Ram AF, van Die I, Routier FH. Galactofuranose in eukaryotes: aspects of biosynthesis and functional impact. Glycobiology 2011; 22:456-69. [DOI: 10.1093/glycob/cwr144] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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