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Brettell LE, Martin SJ, Riegler M, Cook JM. Vulnerability of island insect pollinator communities to pathogens. J Invertebr Pathol 2021; 186:107670. [PMID: 34560107 DOI: 10.1016/j.jip.2021.107670] [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: 06/29/2020] [Revised: 07/26/2021] [Accepted: 09/14/2021] [Indexed: 10/20/2022]
Abstract
Island ecosystems, which often contain undescribed insects and small populations of single island endemics, are at risk from diverse threats. The spread of pathogens is a major factor affecting not just pollinator species themselves, but also posing significant knock-on effects to often fragile island ecosystems through disruption of pollination networks. Insects are vulnerable to diverse pathogens and these can be introduced to islands in a number of ways, e.g. via the introduction of infected managed pollinator hosts (e.g. honey bees and their viruses, in particular Deformed wing virus), long-range migrants (e.g. monarch butterflies and their protozoan parasite, Ophryocystit elektroscirrha) and invasive species (e.g. social wasps are common invaders and are frequently infected with multi-host viruses such as Kashmir bee virus and Moku virus). Furthermore, these introductions can negatively affect island ecosystems through outcompeting native taxa for resources. As such, the greatest threat to island pollinator communities is not one particular pathogen, but the combination of pathogens and introduced and invasive insects that will likely carry them.
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Affiliation(s)
- Laura E Brettell
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place L3 5QA, UK.
| | - Stephen J Martin
- School of Environment and life Sciences, University of Salford, Manchester M5 4WT, UK
| | - Markus Riegler
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - James M Cook
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
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Microbial enzymes catalyzing keratin degradation: Classification, structure, function. Biotechnol Adv 2020; 44:107607. [PMID: 32768519 PMCID: PMC7405893 DOI: 10.1016/j.biotechadv.2020.107607] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 12/11/2022]
Abstract
Keratin is an insoluble and protein-rich epidermal material found in e.g. feather, wool, hair. It is produced in substantial amounts as co-product from poultry processing plants and pig slaughterhouses. Keratin is packed by disulfide bonds and hydrogen bonds. Based on the secondary structure, keratin can be classified into α-keratin and β-keratin. Keratinases (EC 3.4.-.- peptide hydrolases) have major potential to degrade keratin for sustainable recycling of the protein and amino acids. Currently, the known keratinolytic enzymes belong to at least 14 different protease families: S1, S8, S9, S10, S16, M3, M4, M14, M16, M28, M32, M36, M38, M55 (MEROPS database). The various keratinolytic enzymes act via endo-attack (proteases in families S1, S8, S16, M4, M16, M36), exo-attack (proteases in families S9, S10, M14, M28, M38, M55) or by action only on oligopeptides (proteases in families M3, M32), respectively. Other enzymes, particularly disulfide reductases, also play a key role in keratin degradation as they catalyze the breakage of disulfide bonds for better keratinase catalysis. This review aims to contribute an overview of keratin biomass as an enzyme substrate and a systematic analysis of currently sequenced keratinolytic enzymes and their classification and reaction mechanisms. We also summarize and discuss keratinase assays, available keratinase structures and finally examine the available data on uses of keratinases in practical biorefinery protein upcycling applications.
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Semenova TA, Dunaevsky YE, Beljakova GA, Belozersky MA. Extracellular peptidases of insect-associated fungi and their possible use in biological control programs and as pathogenicity markers. Fungal Biol 2020; 124:65-72. [PMID: 31892378 DOI: 10.1016/j.funbio.2019.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 01/12/2023]
Abstract
This review deals with characteristics of peptidases of fungi whose life cycles are associated with insects to varying degrees. The review examines the characteristic features of the extracellular peptidases of entomopathogenic fungi, the dependence of the specificity of these peptidases on the ecological characteristics of the fungi, and the role of peptidases in the development of the pathogenesis. Data on the properties and physiological role of hydrolytic enzymes of symbiotic fungi in "fungal gardens" are also considered in detail. For the development of representations about mechanisms of control over populations of insect pests, special attention is given to analysis of possibilities of genetic engineering for the creation of entomopathogens with enhanced virulence. Clarification of the role of fungi and their secreted enzymes and careful environmental studies are still required to explain their significance in the composition of the biota and to ensure widespread adoption of these organisms as effective biological control agents. The systematization and comparative analysis of the existing data on extracellular peptidases of insect-associated fungi will help in the planning of further work and the search for markers of pathogenesis and symbiosis.
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Affiliation(s)
| | - Yakov E Dunaevsky
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia.
| | | | - Mikhail A Belozersky
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
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Majeed M, Soliman H, Kumar G, El-Matbouli M, Saleh M. Editing the genome of Aphanomyces invadans using CRISPR/Cas9. Parasit Vectors 2018; 11:554. [PMID: 30352624 PMCID: PMC6199749 DOI: 10.1186/s13071-018-3134-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 10/03/2018] [Indexed: 12/26/2022] Open
Abstract
Background The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system is increasingly being used for genome editing experiments. It is a system to add, delete and/or replace parts of a gene in situ in a time- and cost-efficient manner. The genome of many organisms has been edited using this system. We tested the CRISPR/Cas9 system in Aphanomyces invadans, an oomycete, which is the causative agent of epizootic ulcerative syndrome (EUS) in many fish species. Extracellular proteases produced by this oomycete are believed to play a role in EUS virulence. Methods We designed three single guide-RNAs (gRNA) to target A. invadans serine protease gene. These gRNAs were individually combined with the Cas9 to form ribo-nucleo-protein (RNP) complex. A. invadans protoplasts were then transfected with RNP complexes. After the transfection, the target gene was amplified and subjected to sequencing. Zoospores of A. invadans were also transfected with the RNP complex. Three groups of dwarf gourami (Trichogaster lalius) were then experimentally inoculated with (i) non-treated A. invadans zoospores; (ii) RNP-treated A. invadans zoospores; and (iii) autoclaved pond water as negative control, to investigate the effect of edited serine protease gene on the virulence of A. invadans in vivo. Results Fluorescence microscopy showed sub-cellular localization of RNP complex in A. invadans protoplasts and zoospores. Sequencing results from the protoplast DNA revealed a point mutation in the target gene. A matching mutation was also detected in zoospores after similar treatment with the same RNP complex. In vivo results showed that the CRISPR/Cas9-treated A. invadans zoospores did not produce EUS clinical signs in the fish. These results were then confirmed by histopathological staining of the muscle sections using Gomori’s methenamine silver nitrate and hematoxylin and eosin stains. Conclusions Results obtained in this study indicate that the RNP complex caused effective mutation in the target gene. This hindered the production of serine protease, which ultimately impeded the manifestation of EUS in the fish. Our methods thus establish a promising approach for functional genomics studies in A. invadans and provide novel avenues to develop effective strategies to control this pathogen.
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Affiliation(s)
- Muhammad Majeed
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Vienna, Austria
| | - Hatem Soliman
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Vienna, Austria
| | - Gokhlesh Kumar
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Vienna, Austria
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Vienna, Austria.
| | - Mona Saleh
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Vienna, Austria
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Zhou R, Zhou X, Fan A, Wang Z, Huang B. Differential Functions of Two Metalloproteases, Mrmep1 and Mrmep2, in Growth, Sporulation, Cell Wall Integrity, and Virulence in the Filamentous Fungus Metarhizium robertsii. Front Microbiol 2018; 9:1528. [PMID: 30034386 PMCID: PMC6043653 DOI: 10.3389/fmicb.2018.01528] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/19/2018] [Indexed: 11/13/2022] Open
Abstract
The Metarhizium genus of filamentous entomopathogenic fungi plays a pivotal role in regulating insect populations. Metalloproteases (MEPs) are a widely distributed and diverse family of hydrolytic enzymes that are important toxicity factors in the interactions between fungi and their hosts. Herein, we characterized two MEPs, Mrmep1 and Mrmep2, in Metarhizium robertsii using gene deletion. Growth rates of the resulting ΔMrmep1 and ΔMrmep2 mutants decreased by 16.2 and 16.5%, respectively, relative to the wild-type (WT) strain. Both mutants were less sensitive to cell wall-perturbing agents, sodium dodecyl sulfate and Congo red than the WT strain, whereas did not show any obvious changes in fungal sensitivity to ultraviolet B irradiation or heat stress. The conidial yield of ΔMrmep1, ΔMrmep2, and ΔMrmep1ΔMrmep2 mutants decreased by 56.0, 23, and 53%, respectively. Insect bioassay revealed that median lethal time values against Galleria mellonella increased by 25.5% (ΔMrmep1), 19% (ΔMrmep2), and 28.8% (ΔMrmep1ΔMrmep2) compared with the WT strain at a concentration of 1 × 107 conidia mL-1, suggesting attenuated fungal virulence in the ΔMrmep1, ΔMrmep2, and ΔMrmep1ΔMrmep2 strains. During fungal infection, transcription levels of Mrmep1 was 1.6-fold higher than Mrmep2 at 36 h post inoculation. Additionally, transcription levels of gallerimycin gene were 1.2-fold, 2.18-fold, and 2.5-fold higher in insects infected with the ΔMrmep1, ΔMrmep2, or ΔMrmep1ΔMrmep2 mutant than those infected with the WT strain, respectively. Our findings suggest that Mrmep1 and Mrmep2 are differentially contributed to the growth, sporulation, cell wall integrity, and virulence of M. robertsii.
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Affiliation(s)
- Rong Zhou
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
| | - Xiazhi Zhou
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
| | - Ali Fan
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
| | - Zhangxun Wang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China.,School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Bo Huang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
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Wang J, Zhou X, Guo K, Zhang X, Lin H, Montalva C. Transcriptomic insight into pathogenicity-associated factors of Conidiobolus obscurus, an obligate aphid-pathogenic fungus belonging to Entomopthoromycota. PEST MANAGEMENT SCIENCE 2018; 74:1677-1686. [PMID: 29337410 DOI: 10.1002/ps.4861] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 10/17/2017] [Accepted: 01/10/2018] [Indexed: 06/07/2023]
Abstract
BACKGROUND Conidiobolus obscurus is a widespread fungal entomopathogen with aphid biocontrol potential. This study focused on a de novo transcriptomic analysis of C. obscurus. RESULTS A number of pathogenicity-associated factors were annotated for the first time from the assembled 17 231 fungal unigenes, including those encoding subtilisin-like proteolytic enzymes (Pr1s), trypsin-like proteases, metalloproteases, carboxypeptidases and endochitinases. Many of these genes were transcriptionally up-regulated by at least twofold in mycotized cadavers compared with the in vitro fungal cultures. The resultant transcriptomic database was validated by the transcript levels of three selected pathogenicity-related genes quantified from different in vivo and in vitro material in real-time quantitative polymerase chain reaction (PCR). The involvement of multiple Pr1 proteases in the first stage of fungal infection was also suggested. Interestingly, a unique cytolytic (Cyt)-like δ-endotoxin gene was highly expressed in both mycotized cadavers and fungal cultures, and was more or less distinct from its homologues in bacteria and other fungi. CONCLUSION Our findings provide the first global insight into various pathogenicity-related genes in this obligate aphid pathogen and may help to develop novel biocontrol strategy against aphid pests. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Jianghong Wang
- National Joint Local Engineering Laboratory for High-Efficient Preparation of Biopesticide, School of Forestry and Biotechnology, Zhejiang Agricultural and Forestry University, Lin'an, People's Republic of China
| | - Xiang Zhou
- National Joint Local Engineering Laboratory for High-Efficient Preparation of Biopesticide, School of Forestry and Biotechnology, Zhejiang Agricultural and Forestry University, Lin'an, People's Republic of China
- Department of Biological Sciences, University of Wisconsin, Milwaukee, WI, USA
| | - Kai Guo
- National Joint Local Engineering Laboratory for High-Efficient Preparation of Biopesticide, School of Forestry and Biotechnology, Zhejiang Agricultural and Forestry University, Lin'an, People's Republic of China
| | - Xinqi Zhang
- National Joint Local Engineering Laboratory for High-Efficient Preparation of Biopesticide, School of Forestry and Biotechnology, Zhejiang Agricultural and Forestry University, Lin'an, People's Republic of China
| | - Haiping Lin
- National Joint Local Engineering Laboratory for High-Efficient Preparation of Biopesticide, School of Forestry and Biotechnology, Zhejiang Agricultural and Forestry University, Lin'an, People's Republic of China
| | - Cristian Montalva
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
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Agbowuro AA, Huston WM, Gamble AB, Tyndall JDA. Proteases and protease inhibitors in infectious diseases. Med Res Rev 2017; 38:1295-1331. [PMID: 29149530 DOI: 10.1002/med.21475] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/10/2017] [Accepted: 10/17/2017] [Indexed: 12/31/2022]
Abstract
There are numerous proteases of pathogenic organisms that are currently targeted for therapeutic intervention along with many that are seen as potential drug targets. This review discusses the chemical and biological makeup of some key druggable proteases expressed by the five major classes of disease causing agents, namely bacteria, viruses, fungi, eukaryotes, and prions. While a few of these enzymes including HIV protease and HCV NS3-4A protease have been targeted to a clinically useful level, a number are yet to yield any clinical outcomes in terms of antimicrobial therapy. A significant aspect of this review discusses the chemical and pharmacological characteristics of inhibitors of the various proteases discussed. A total of 25 inhibitors have been considered potent and safe enough to be trialed in humans and are at different levels of clinical application. We assess the mechanism of action and clinical performance of the protease inhibitors against infectious agents with their developmental strategies and look to the next frontiers in the use of protease inhibitors as anti-infective agents.
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Affiliation(s)
| | - Wilhelmina M Huston
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, Australia
| | - Allan B Gamble
- School of Pharmacy, University of Otago, Dunedin, New Zealand
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Co-inoculum of Beauveria brongniartii and B. bassiana shows in vitro different metabolic behaviour in comparison to single inoculums. Sci Rep 2017; 7:13102. [PMID: 29026120 PMCID: PMC5638874 DOI: 10.1038/s41598-017-12700-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/13/2017] [Indexed: 12/11/2022] Open
Abstract
The use of entomopathogenic fungi for biocontrol of plant pests is recently receiving an increased interest due to the need of reducing the impact of agricultural practices on the environment. Biocontrol efficacy could be improved by co-inoculation of different microorganisms. However, interactions between the fungal species can trigger or depress the biocontrol activity. Co-inoculation of two entomopathogenic fungi (Beauveria bassiana and B. brongniartii) was performed in vitro to evaluate the effects of their joint behaviour on a range of different carbon sources in comparison to single inoculation. The two species showed a very different metabolic profile by Phenotype MicroArrayTM. B. bassiana showed a broader metabolism than B. brongniartii on a range of substrates. B. brongniartii showed a greater specificity in substrate utilization. Several carbon sources (L-Asparagine, L-Aspartic Acid, L- Glutamic Acid, m- Erythritol, D-Melezitose, D-Sorbitol) triggered the fungal metabolism in the co-inoculum. SSR markers and Real Time qPCR analysis showed that different substrates promoted either the growth of one or the other species, suggesting a form of interaction between the two fungi, related to their different ecological niches. The methodological approach that combines Phenotype MicroArrayTM and SSR genotyping appeared useful to assess the performance and potential competition of co-inoculated entomopathogenic fungi.
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Gryganskyi AP, Mullens BA, Gajdeczka MT, Rehner SA, Vilgalys R, Hajek AE. Hijacked: Co-option of host behavior by entomophthoralean fungi. PLoS Pathog 2017; 13:e1006274. [PMID: 28472199 PMCID: PMC5417710 DOI: 10.1371/journal.ppat.1006274] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Andrii P. Gryganskyi
- Department of Biology, Duke University, Durham, North Carolina, United States of America
- * E-mail:
| | - Bradley A. Mullens
- Department of Entomology, University of California Riverside, Riverside, California, United States of America
| | - Michael T. Gajdeczka
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Stephen A. Rehner
- Systematic Mycology and Microbiology Laboratory, USDA-ARS, Beltsville, Maryland, United States of America
| | - Rytas Vilgalys
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Ann E. Hajek
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
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Correa AF, Bastos IMD, Neves D, Kipnis A, Junqueira-Kipnis AP, de Santana JM. The Activity of a Hexameric M17 Metallo-Aminopeptidase Is Associated With Survival of Mycobacterium tuberculosis. Front Microbiol 2017; 8:504. [PMID: 28396657 PMCID: PMC5366330 DOI: 10.3389/fmicb.2017.00504] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 03/10/2017] [Indexed: 01/06/2023] Open
Abstract
Mycobacterium tuberculosis is one of the most prevalent human pathogens causing millions of deaths in the last years. Moreover, tuberculosis (TB) treatment has become increasingly challenging owing to the emergence of multidrug resistant M. tuberculosis strains. Thus, there is an immediate need for the development of new anti-TB drugs. Proteases appear to be a promising approach and may lead to shortened and effective treatments for drug-resistant TB. Although the M. tuberculosis genome predicts more than 100 genes encoding proteases, only a few of them have been studied. Aminopeptidases constitute a set of proteases that selectively remove amino acids from the N-terminus of proteins and peptides and may act as virulence factors, essential for survival and maintenance of many microbial pathogens. Here, we characterized a leucine aminopeptidase of M. tuberculosis (MtLAP) as a cytosolic oligomeric metallo-aminopeptidase. Molecular and enzymatic properties lead us to classify MtLAP as a typical member of the peptidase family M17. Furthermore, the aminopeptidase inhibitor bestatin strongly inhibited MtLAP activity, in vitro M. tuberculosis growth and macrophage infection. In murine model of TB, bestatin treatment reduced bacterial burden and lesion in the lungs of infected mice. Thus, our data suggest that MtLAP participates in important metabolic pathways of M. tuberculosis necessary for its survival and virulence and consequently may be a promising target for new anti-TB drugs.
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Affiliation(s)
- Andre F Correa
- Laboratório de Interação Patógeno-Hospedeiro, Instituto de Biologia Universidade de BrasíliaBrasília, Brazil; Instituto de Patologia Tropical e Saúde Pública Universidade Federal de GoiásGoiânia, Brazil
| | - Izabela M D Bastos
- Laboratório de Interação Patógeno-Hospedeiro, Instituto de Biologia Universidade de Brasília Brasília, Brazil
| | - David Neves
- Laboratório de Interação Patógeno-Hospedeiro, Instituto de Biologia Universidade de Brasília Brasília, Brazil
| | - Andre Kipnis
- Instituto de Patologia Tropical e Saúde Pública Universidade Federal de Goiás Goiânia, Brazil
| | - Ana P Junqueira-Kipnis
- Instituto de Patologia Tropical e Saúde Pública Universidade Federal de Goiás Goiânia, Brazil
| | - Jaime M de Santana
- Laboratório de Interação Patógeno-Hospedeiro, Instituto de Biologia Universidade de Brasília Brasília, Brazil
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De Fine Licht HH, Jensen AB, Eilenberg J. Comparative transcriptomics reveal host-specific nucleotide variation in entomophthoralean fungi. Mol Ecol 2016; 26:2092-2110. [PMID: 27717247 DOI: 10.1111/mec.13863] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 09/13/2016] [Accepted: 09/15/2016] [Indexed: 12/15/2022]
Abstract
Obligate parasites are under strong selection to increase exploitation of their host to survive while evading detection by host immune defences. This has often led to elaborate pathogen adaptations and extreme host specificity. Specialization on one host, however, often incurs a trade-off influencing the capacity to infect alternate hosts. Here, we investigate host adaptation in two morphologically indistinguishable and closely related obligate specialist insect-pathogenic fungi from the phylum Entomophthoromycota, Entomophthora muscae sensu stricto and E. muscae sensu lato, pathogens of houseflies (Musca domestica) and cabbage flies (Delia radicum), respectively. We compared single nucleotide polymorphisms within and between these two E. muscae species using 12 RNA-seq transcriptomes from five biological samples. All five isolates contained intra-isolate polymorphisms that segregate in 50:50 ratios, indicative of genetic duplication events or functional diploidy. Comparative analysis of dN/dS ratios between the multinucleate E. muscae s.str. and E. muscae s.l. revealed molecular signatures of positive selection in transcripts related to utilization of host lipids and the potential secretion of toxins that interfere with the host immune response. Phylogenetic comparison with the nonobligate generalist insect-pathogenic fungus Conidiobolus coronatus revealed a gene-family expansion of trehalase enzymes in E. muscae. The main sugar in insect haemolymph is trehalose, and efficient sugar utilization was probably important for the evolutionary transition to obligate insect pathogenicity in E. muscae. These results support the hypothesis that genetically based host specialization in specialist pathogens evolves in response to the challenge of using resources and dealing with the immune system of different hosts.
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Affiliation(s)
- Henrik H De Fine Licht
- Section for Organismal Biology, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Annette B Jensen
- Section for Organismal Biology, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Jørgen Eilenberg
- Section for Organismal Biology, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
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Utilizing Genomics to Study Entomopathogenicity in the Fungal Phylum Entomophthoromycota. ADVANCES IN GENETICS 2016; 94:41-65. [DOI: 10.1016/bs.adgen.2016.01.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Małagocka J, Grell MN, Lange L, Eilenberg J, Jensen AB. Transcriptome of an entomophthoralean fungus (Pandora formicae) shows molecular machinery adjusted for successful host exploitation and transmission. J Invertebr Pathol 2015; 128:47-56. [DOI: 10.1016/j.jip.2015.05.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 04/09/2015] [Accepted: 05/04/2015] [Indexed: 10/23/2022]
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14
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Invasion of the central nervous system by Cryptococcus neoformans requires a secreted fungal metalloprotease. mBio 2014; 5:e01101-14. [PMID: 24895304 PMCID: PMC4049100 DOI: 10.1128/mbio.01101-14] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Cryptococcus spp. cause life-threatening fungal infection of the central nervous system (CNS), predominantly in patients with a compromised immune system. Why Cryptococcus neoformans has this remarkable tropism for the CNS is not clear. Recent research on cerebral pathogenesis of C. neoformans revealed a predominantly transcellular migration of cryptococci across the brain endothelium; however, the identities of key fungal virulence factors that function specifically to invade the CNS remain unresolved. Here we found that a novel, secreted metalloprotease (Mpr1) that we identified in the extracellular proteome of C. neoformans (CnMpr1) is required for establishing fungal disease in the CNS. Mpr1 belongs to a poorly characterized M36 class of fungalysins that are expressed in only some fungal species. A strain of C. neoformans lacking the gene encoding Mpr1 (mpr1Δ) failed to breach the endothelium in an in vitro model of the human blood-brain barrier (BBB). A mammalian host infected with the mpr1Δ null strain demonstrated significant improvement in survival due to a reduced brain fungal burden and lacked the brain pathology commonly associated with cryptococcal disease. The in vivo studies further indicate that Mpr1 is not required for fungal dissemination and Mpr1 likely targets the brain endothelium specifically. Remarkably, the sole expression of CnMPR1 in Saccharomyces cerevisiae resulted in a robust migration of yeast cells across the brain endothelium, demonstrating Mpr1's specific activity in breaching the BBB and suggesting that Mpr1 may function independently of the hyaluronic acid-CD44 pathway. This distinct role for Mpr1 may develop into innovative treatment options and facilitate a brain-specific drug delivery platform. IMPORTANCE Cryptococcus neoformans is a medically relevant fungal pathogen causing significant morbidity and mortality, particularly in immunocompromised individuals. An intriguing feature is its strong neurotropism, and consequently the hallmark of cryptococcal disease is a brain infection, cryptococcal meningoencephalitis. For C. neoformans to penetrate the central nervous system (CNS), it first breaches the blood-brain barrier via a transcellular pathway; however, the identities of fungal factors required for this transmigration remain largely unknown. In an effort to identify extracellular fungal proteins that could mediate interactions with the brain endothelium, we undertook a proteomic analysis of the extracellular proteome and identified a secreted metalloprotease (Mpr1) belonging to the M36 class of fungalysins. Here we found that Mpr1 promotes migration of C. neoformans across the brain endothelium and into the CNS by facilitating attachment of cryptococci to the endothelium surface, thus underscoring the critical role of M36 proteases in fungal pathogenesis.
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Naumann TA, Wicklow DT, Price NPJ. Identification of a chitinase-modifying protein from Fusarium verticillioides: truncation of a host resistance protein by a fungalysin metalloprotease. J Biol Chem 2011; 286:35358-35366. [PMID: 21878653 PMCID: PMC3195611 DOI: 10.1074/jbc.m111.279646] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 08/23/2011] [Indexed: 11/06/2022] Open
Abstract
Chitinase-modifying proteins (cmps) are proteases secreted by fungal pathogens that truncate the plant class IV chitinases ChitA and ChitB during maize ear rot. cmp activity has been characterized for Bipolaris zeicola and Stenocarpella maydis, but the identities of the proteases are not known. Here, we report that cmps are secreted by multiple species from the genus Fusarium, that cmp from Fusarium verticillioides (Fv-cmp) is a fungalysin metalloprotease, and that it cleaves within a sequence that is conserved in class IV chitinases. Protein extracts from Fusarium cultures were found to truncate ChitA and ChitB in vitro. Based on this activity, Fv-cmp was purified from F. verticillioides. N-terminal sequencing of truncated ChitA and MALDI-TOF-MS analysis of reaction products showed that Fv-cmp is an endoprotease that cleaves a peptide bond on the C-terminal side of the lectin domain. The N-terminal sequence of purified Fv-cmp was determined and compared with a set of predicted proteins, resulting in its identification as a zinc metalloprotease of the fungalysin family. Recombinant Fv-cmp also truncated ChitA, confirming its identity, but had reduced activity, suggesting that the recombinant protease did not mature efficiently from its propeptide-containing precursor. This is the first report of a fungalysin that targets a nonstructural host protein and the first to implicate this class of virulence-related proteases in plant disease.
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Affiliation(s)
- Todd A Naumann
- Bacterial Foodborne Pathogens and Mycology Research Unit, National Center for Agricultural Utilization Research, Peoria, Illinois 61604.
| | - Donald T Wicklow
- Bacterial Foodborne Pathogens and Mycology Research Unit, National Center for Agricultural Utilization Research, Peoria, Illinois 61604
| | - Neil P J Price
- Renewable Product Technology Research Unit, National Center for Agricultural Utilization Research, Peoria, Illinois 61604
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Grell MN, Jensen AB, Olsen PB, Eilenberg J, Lange L. Secretome of fungus-infected aphids documents high pathogen activity and weak host response. Fungal Genet Biol 2011; 48:343-52. [DOI: 10.1016/j.fgb.2010.12.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 11/14/2010] [Accepted: 12/08/2010] [Indexed: 11/26/2022]
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17
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Santi L, Silva WO, Pinto AF, Schrank A, Vainstein MH. Metarhizium anisopliae host–pathogen interaction: differential immunoproteomics reveals proteins involved in the infection process of arthropods. Fungal Biol 2010; 114:312-9. [DOI: 10.1016/j.funbio.2010.01.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 01/05/2010] [Accepted: 01/22/2010] [Indexed: 11/26/2022]
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Comparative EST analysis of a Zoophthora radicans isolate derived from Pieris brassicae and an isogenic strain adapted to Plutella xylostella. Microbiology (Reading) 2009; 155:174-185. [DOI: 10.1099/mic.0.022103-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Zoophthora radicansis an entomopathogenic fungus with the potential to be used as an insect biological control agent. To better understand the mechanisms used byZ. radicansto infect different hosts, we generated expressed sequence tag (EST) datasets from aZ. radicansstrain originally isolated fromPieris brassicae, and an isogenic strain passaged throughPlutella xylostella. In total, 1839 ESTs were generated which clustered into 466 contigs and 433 singletons to provide a set of 899 unique sequences. Approximately 85 % of the ESTs were significantly similar (E≤e−03) to other fungal genes, of which 69.6 % encoded proteins with a reported function. Proteins involved in protein synthesis and metabolism were encoded by 38.3 % of the ESTs, while 26.3 % encoded proteins involved in cell-cycle regulation, DNA synthesis, protein fate, transport, cell defence, transcription and RNA synthesis, and 4.9 % encoded proteins associated with cellular transport, signal transduction, control of cellular organization and cell-wall degradation. Several proteinases, including aspartic proteinases, trypsins, trypsin-like serine proteases and metalloproteases, with the potential to degrade insect cuticle were expressed by the two isolates.
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Global gene expression profiles for life stages of the deadly amphibian pathogen Batrachochytrium dendrobatidis. Proc Natl Acad Sci U S A 2008; 105:17034-9. [PMID: 18852473 DOI: 10.1073/pnas.0804173105] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Amphibians around the world are being threatened by an emerging pathogen, the chytrid fungus Batrachochytrium dendrobatidis (Bd). Despite intensive ecological study in the decade since Bd was discovered, little is known about the mechanism by which Bd kills frogs. Here, we compare patterns of global gene expression in controlled laboratory conditions for the two phases of the life cycle of Bd: the free-living zoospore and the substrate-embedded sporangia. We find zoospores to be transcriptionally less complex than sporangia. Several transcripts more abundant in zoospores provide clues about how this motile life stage interacts with its environment. Genes with higher levels of expression in sporangia provide new hypotheses about the molecular pathways involved in metabolic activity, flagellar function, and pathogenicity in Bd. We highlight expression patterns for a group of fungalysin metallopeptidase genes, a gene family thought to be involved in pathogenicity in another group of fungal pathogens that similarly cause cutaneous infection of vertebrates. Finally we discuss the challenges inherent in developing a molecular toolkit for chytrids, a basal fungal lineage separated by vast phylogenetic distance from other well characterized fungi.
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