Development of a homologous transformation system for the human pathogenic fungus Aspergillus fumigatus based on the pyrG gene encoding orotidine 5′′-monophosphate decarboxylase

1998 ◽  
Vol 33 (5) ◽  
pp. 378-385 ◽  
Author(s):  
Gerhard Weidner ◽  
Christophe d'Enfert ◽  
Andreas Koch ◽  
Pieternella C. Mol ◽  
A. A. Brakhage
Keyword(s):  
Aspergillus Fumigatus ◽  
Pathogenic Fungus ◽  
Transformation System ◽  
Gene Encoding ◽  
Homologous Transformation ◽  
Monophosphate Decarboxylase ◽  
Human Pathogenic Fungus

scholarly journals The Putative APSES Transcription Factor RgdA Governs Growth, Development, Toxigenesis, and Virulence in Aspergillus fumigatus

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Sang-Cheol Jun ◽  
Yong-Ho Choi ◽  
Min-Woo Lee ◽  
Jae-Hyuk Yu ◽  
Kwang-Soo Shin
Keyword(s):  
Transcription Factor ◽  
Aspergillus Fumigatus ◽  
Molecular Mechanisms ◽  
Pathogenic Fungus ◽  
Mrna Levels ◽  
Transcript Levels ◽  
Content Type ◽  
Asexual Sporulation ◽  
Human Pathogenic Fungus ◽  
Growth Development

ABSTRACT The APSES transcription factor (TF) in Aspergillus species is known to govern diverse cellular processes, including growth, development, and secondary metabolism. Here, we investigated functions of the rgdA gene (Afu3g13920) encoding a putative APSES TF in the opportunistic human-pathogenic fungus Aspergillus fumigatus. The rgdA deletion resulted in significantly decreased hyphal growth and asexual sporulation. Consistently, transcript levels of the key asexual developmental regulators abaA, brlA, and wetA were decreased in the ΔrgdA mutant compared to those in the wild type (WT). Moreover, ΔrgdA resulted in reduced spore germination rates and elevated transcript levels of genes associated with conidium dormancy. The conidial cell wall hydrophobicity and architecture were changed, and levels of the RodA protein were decreased in the ΔrgdA mutant. Comparative transcriptomic analyses revealed that the ΔrgdA mutant showed higher mRNA levels of gliotoxin (GT)-biosynthetic genes and GT production. While the ΔrgdA mutant exhibited elevated production of GT, ΔrgdA strains showed reduced virulence in the mouse model. In addition, mRNA levels of genes associated with the cyclic AMP (cAMP)-protein kinase A (PKA) signaling pathway and the SakA mitogen-activated protein (MAP) kinase pathway were increased in the ΔrgdA mutant. In summary, RgdA plays multiple roles in governing growth, development, GT production, and virulence which may involve attenuation of PKA and SakA signaling. IMPORTANCE Immunocompromised patients are susceptible to infections with the opportunistic human-pathogenic fungus Aspergillus fumigatus. This fungus causes systemic infections such as invasive aspergillosis (IA), which is one of the most life-threatening fungal diseases. To control this serious disease, it is critical to identify new antifungal drug targets. In fungi, the transcriptional regulatory proteins of the APSES family play crucial roles in controlling various biological processes, including mating, asexual sporulation and dimorphic growth, and virulence traits. This study found that a putative APSES transcription factor, RgdA, regulates normal growth, asexual development, conidium germination, spore wall architecture and hydrophobicity, toxin production, and virulence in A. fumigatus. Better understanding the molecular mechanisms of RgdA in human-pathogenic fungi may reveal a novel antifungal target for future drug development.

scholarly journals The Opportunistic Human Pathogenic Fungus Aspergillus fumigatus Evades the Host Complement System

2007 ◽  
Vol 76 (2) ◽  
pp. 820-827 ◽  
Author(s):  
Judith Behnsen ◽  
Andrea Hartmann ◽  
Jeannette Schmaler ◽  
Alexander Gehrke ◽  
Axel A. Brakhage ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Complement System ◽  
Developmental Stages ◽  
Fungal Infections ◽  
Alternative Pathway ◽  
Pathogenic Fungus ◽  
Factor H ◽  
Human Sera ◽  
Human Pathogenic Fungus ◽  
Complement Regulators

ABSTRACT The opportunistic human pathogenic fungus Aspergillus fumigatus causes severe systemic infections and is a major cause of fungal infections in immunocompromised patients. A. fumigatus conidia activate the alternative pathway of the complement system. In order to assess the mechanisms by which A. fumigatus evades the activated complement system, we analyzed the binding of host complement regulators to A. fumigatus. The binding of factor H and factor H-like protein 1 (FHL-1) from human sera to A. fumigatus conidia was shown by adsorption assays and immunostaining. In addition, factor H-related protein 1 (FHR-1) bound to conidia. Adsorption assays with recombinant factor H mutants were used to localize the binding domains. One binding region was identified within N-terminal short consensus repeats (SCRs) 1 to 7 and a second one within C-terminal SCR 20. Plasminogen was identified as the fourth host regulatory molecule that binds to A. fumigatus conidia. In contrast to conidia, other developmental stages of A. fumigatus, like swollen conidia or hyphae, did not bind to factor H, FHR-1, FHL-1, and plasminogen, thus indicating the developmentally regulated expression of A. fumigatus surface ligands. Both factor H and plasminogen maintained regulating activity when they were bound to the conidial surface. Bound factor H acted as a cofactor to the factor I-mediated cleavage of C3b. Plasminogen showed proteolytic activity when activated to plasmin by urokinase-type plasminogen activator. These data show that A. fumigatus conidia bind to complement regulators, and these bound host regulators may contribute to evasion of a host complement attack.

scholarly journals Inducible Cell Fusion Permits Use of Competitive Fitness Profiling in the Human Pathogenic Fungus Aspergillus fumigatus

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Darel Macdonald ◽  
Darren D. Thomson ◽  
Anna Johns ◽  
Adriana Contreras Valenzuela ◽  
Jane M. Gilsenan ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Cell Fusion ◽  
Pathogenic Fungus ◽  
Brefeldin A ◽  
Culture Conditions ◽  
Competitive Fitness ◽  
Content Type ◽  
Genetic Profiling ◽  
Standard Culture ◽  
Human Pathogenic Fungus

ABSTRACT Antifungal agents directed against novel therapeutic targets are required for treating invasive, chronic, and allergic Aspergillus infections. Competitive fitness profiling technologies have been used in a number of bacterial and yeast systems to identify druggable targets; however, the development of similar systems in filamentous fungi is complicated by the fact that they undergo cell fusion and heterokaryosis. Here, we demonstrate that cell fusion in Aspergillus fumigatus under standard culture conditions is not predominately constitutive, as with most ascomycetes, but can be induced by a range of extracellular stressors. Using this knowledge, we have developed a barcode-free genetic profiling system that permits high-throughput parallel determination of strain fitness in a collection of diploid A. fumigatus mutants. We show that heterozygous cyp51A and arf2 null mutants have reduced fitness in the presence of itraconazole and brefeldin A, respectively, and a heterozygous atp17 null mutant is resistant to brefeldin A.

scholarly journals Fluorescence Polarization Binding Assay for Aspergillus fumigatus Virulence Factor UDP-Galactopyranose Mutase

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jun Qi ◽  
Michelle Oppenheimer ◽  
Pablo Sobrado
Keyword(s):  
Aspergillus Fumigatus ◽  
Fluorescence Polarization ◽  
Binding Assay ◽  
Pathogenic Fungus ◽  
Affinity Binding ◽  
Good Tolerance ◽  
High Affinity ◽  
Essential Components ◽  
Human Pathogenic Fungus ◽  
Lung Infections

Aspergillus fumigatus is an opportunistic human pathogenic fungus responsible for deadly lung infections in immunocompromised individuals. Galactofuranose (Galf) residues are essential components of the cell wall and play an important role in A. fumigatus virulence. The flavoenzyme UDP-galactopyranose mutase (UGM) catalyzes the isomerization of UDP-galactopyranose to UDP-galactofuranose, the biosynthetic precursor of Galf. Thus, inhibitors of UGM that block the biosynthesis of Galf can lead to novel chemotherapeutics for treating A. fumigatus-related diseases. Here, we describe the synthesis of fluorescently labeled UDP analogs and the development of a fluorescence polarization (FP) binding assay for A. fumigatus UGM (AfUGM). High-affinity binding to AfUGM was only obtained with the chromophore TAMRA, linked to UDP by either 2 or 6 carbons with Kd values of 2.6 ± 0.2 μM and 3.0 ± 0.7 μM, respectively. These values were ~6 times lower than when UDP was linked to fluorescein. The FP assay was validated against several known ligands and displayed an excellent Z′ factor (0.79 ± 0.02) and good tolerance to dimethyl sulfoxide.

Identification of the antiphagocytic trypacidin gene cluster in the human-pathogenic fungus Aspergillus fumigatus

2015 ◽  
Vol 99 (23) ◽  
pp. 10151-10161 ◽  
Author(s):  
Derek J. Mattern ◽  
Hanno Schoeler ◽  
Jakob Weber ◽  
Silvia Novohradská ◽  
Kaswara Kraibooj ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Gene Cluster ◽  
Pathogenic Fungus ◽  
Human Pathogenic Fungus
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