FKBP12 dimerization mutations effect FK506 binding and differentially alter calcineurin inhibition in the human pathogen Aspergillus fumigatus

Microfungi can colonize stone surfaces and form sub-aerial biofilms which can lead to biodeterioration of historic monuments. In this investigation samples for mycological analyses were collected from stone material with visible alteration on stone walls of Gradac monastery exterior. The prevailing fungi found on stone walls were dematiaceous hyphomycetes with melanized hyphae and reproductive structures (Alternaria, Aureobasidium, Cladosporium and Epicoccum species). The frescoes inside the monastery building were also analyzed for the presence of mycobiota. The predominant fungi found on frescoes were osmophilic species from genera Aspergillus and Penicillium. The significant result is identification of human pathogen species Aspergillus fumigatus on frescoes.

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The Protective Role of 1,8-Dihydroxynaphthalene–Melanin on Conidia of the Opportunistic Human Pathogen Aspergillus fumigatus Revisited: No Role in Protection against Hydrogen Peroxide and Superoxides

mSphere ◽

10.1128/msphere.00874-21 ◽

2022 ◽

Author(s):

E. M. Keizer ◽

I. D. Valdes ◽

B. L. McCann ◽

E. M. Bignell ◽

H. A. B. Wösten ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Aspergillus Fumigatus ◽

Protective Role ◽

Oxygen Species ◽

Human Pathogen ◽

Opportunistic Pathogens ◽

Green Pigment ◽

Content Type ◽

Opportunistic Human Pathogen

Opportunistic pathogens like Aspergillus fumigatus have strategies to protect themselves against reactive oxygen species like hydrogen peroxides and superoxides that are produced by immune cells. DHN-melanin is the green pigment on conidia of Aspergillus fumigatus and more than 2 decades ago was reported to protect conidia against hydrogen peroxide.

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The Siderophore Transporters Sit1 and Sit2 Are Essential for Utilization of Ferrichrome-, Ferrioxamine- and Coprogen-Type Siderophores in Aspergillus fumigatus

Journal of Fungi ◽

10.3390/jof7090768 ◽

2021 ◽

Vol 7 (9) ◽

pp. 768

Author(s):

Mario Aguiar ◽

Thomas Orasch ◽

Matthias Misslinger ◽

Anna-Maria Dietl ◽

Fabio Gsaller ◽

...

Keyword(s):

Aspergillus Fumigatus ◽

Filamentous Fungi ◽

Fungal Pathogens ◽

Fungal Infections ◽

The Novel ◽

Human Pathogen ◽

Substrate Specificities ◽

Triacetylfusarinine C ◽

Opportunistic Human Pathogen ◽

Siderophore Transporter

Siderophore-mediated acquisition of iron has been shown to be indispensable for the virulence of several fungal pathogens, the siderophore transporter Sit1 was found to mediate uptake of the novel antifungal drug VL-2397, and siderophores were shown to be useful as biomarkers as well as for imaging of fungal infections. However, siderophore uptake in filamentous fungi is poorly characterized. The opportunistic human pathogen Aspergillus fumigatus possesses five putative siderophore transporters. Here, we demonstrate that the siderophore transporters Sit1 and Sit2 have overlapping, as well as unique, substrate specificities. With respect to ferrichrome-type siderophores, the utilization of ferrirhodin and ferrirubin depended exclusively on Sit2, use of ferrichrome A depended mainly on Sit1, and utilization of ferrichrome, ferricrocin, and ferrichrysin was mediated by both transporters. Moreover, both Sit1 and Sit2 mediated use of the coprogen-type siderophores coprogen and coprogen B, while only Sit1 transported the bacterial ferrioxamine-type xenosiderophores ferrioxamines B, G, and E. Neither Sit1 nor Sit2 were important for the utilization of the endogenous siderophores fusarinine C and triacetylfusarinine C. Furthermore, A. fumigatus was found to lack utilization of the xenosiderophores schizokinen, basidiochrome, rhizoferrin, ornibactin, rhodotorulic acid, and enterobactin. Taken together, this study characterized siderophore use by A. fumigatus and substrate characteristics of Sit1 and Sit2.

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The Protein Kinase A-Dependent Phosphoproteome of the Human Pathogen Aspergillus fumigatus Reveals Diverse Virulence-Associated Kinase Targets

mBio ◽

10.1128/mbio.02880-20 ◽

2020 ◽

Vol 11 (6) ◽

pp. e02880-20

Author(s):

E. Keats Shwab ◽

Praveen R. Juvvadi ◽

Greg Waitt ◽

Shareef Shaheen ◽

John Allen ◽

...

Keyword(s):

Infectious Disease ◽

Protein Kinase ◽

Aspergillus Fumigatus ◽

Protein Kinase A ◽

Molecular Mechanisms ◽

Targeted Mutagenesis ◽

Human Pathogen ◽

Content Type ◽

Kinase A ◽

Microbial Disease

ABSTRACTProtein kinase A (PKA) signaling plays a critical role in the growth and development of all eukaryotic microbes. However, few direct targets have been characterized in any organism. The fungus Aspergillus fumigatus is a leading infectious cause of death in immunocompromised patients, but the specific molecular mechanisms responsible for its pathogenesis are poorly understood. We used this important pathogen as a platform for a comprehensive and multifaceted interrogation of both the PKA-dependent whole proteome and phosphoproteome in order to elucidate the mechanisms through which PKA signaling regulates invasive microbial disease. Employing advanced quantitative whole-proteomic and phosphoproteomic approaches with two complementary phosphopeptide enrichment strategies, coupled to an independent PKA interactome analysis, we defined distinct PKA-regulated pathways and identified novel direct PKA targets contributing to pathogenesis. We discovered three previously uncharacterized virulence-associated PKA effectors, including an autophagy-related protein, Atg24; a CCAAT-binding transcriptional regulator, HapB; and a CCR4-NOT complex-associated ubiquitin ligase, Not4. Targeted mutagenesis, combined with in vitro kinase assays, multiple murine infection models, structural modeling, and molecular dynamics simulations, was employed to characterize the roles of these new PKA targets in growth, environmental and antimicrobial stress responses, and pathogenesis in a mammalian system. We also elucidated the molecular mechanisms of PKA regulation for these effectors by defining the functionality of phosphorylation at specific PKA target sites. We have comprehensively characterized the PKA-dependent phosphoproteome and validated PKA targets as direct regulators of infectious disease for the first time in any pathogen, providing new insights into PKA signaling and control over microbial pathogenesis.IMPORTANCE PKA is essential for the virulence of eukaryotic human pathogens. Understanding PKA signaling mechanisms is therefore fundamental to deciphering pathogenesis and developing novel therapies. Despite its ubiquitous necessity, specific PKA effectors underlying microbial disease remain unknown. To address this fundamental knowledge gap, we examined the whole-proteomic and phosphoproteomic impacts of PKA on the deadly fungal pathogen Aspergillus fumigatus to uncover novel PKA targets controlling growth and virulence. We also defined the functional consequences of specific posttranslational modifications of these target proteins to characterize the molecular mechanisms of pathogenic effector regulation by PKA. This study constitutes the most comprehensive analysis of the PKA-dependent phosphoproteome of any human pathogen and proposes new and complex roles played by PKA signaling networks in governing infectious disease.

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Characterization of the putative polysaccharide synthase CpsA and its effects on the virulence of the human pathogen Aspergillus fumigatus

PLoS ONE ◽

10.1371/journal.pone.0216092 ◽

2019 ◽

Vol 14 (4) ◽

pp. e0216092 ◽

Cited By ~ 3

Author(s):

Binita Nepal ◽

Ryan Myers ◽

Jessica M. Lohmar ◽

Olivier Puel ◽

Brett Thompson ◽

...

Keyword(s):

Aspergillus Fumigatus ◽

Human Pathogen

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EP007 Analysis of interactions of macrophages with the opportunistic human pathogen Aspergillus fumigatus

International Journal of Medical Microbiology Supplements ◽

10.1016/s1433-1128(03)80711-8 ◽

2003 ◽

Vol 293 ◽

pp. 224-225

Keyword(s):

Aspergillus Fumigatus ◽

Human Pathogen ◽

Opportunistic Human Pathogen

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Upstream and Downstream Regulation of Asexual Development in Aspergillus fumigatus

Eukaryotic Cell ◽

10.1128/ec.00192-06 ◽

2006 ◽

Vol 5 (10) ◽

pp. 1585-1595 ◽

Cited By ~ 104

Author(s):

Jae-Hyung Mah ◽

Jae-Hyuk Yu

Keyword(s):

Aspergillus Fumigatus ◽

G Proteins ◽

Asexual Development ◽

Human Pathogen ◽

Loss Of Function ◽

Primary Target ◽

Asexual Sporulation ◽

Opportunistic Human Pathogen ◽

Upstream Regulators ◽

Primary Agent

ABSTRACT The opportunistic human pathogen Aspergillus fumigatus produces a large quantity of asexual spores (conidia), which are the primary agent causing invasive aspergillosis in immunocompromised patients. We investigated the mechanisms controlling asexual sporulation (conidiation) in A. fumigatus via examining functions of four key regulators, GpaA (Gα), AfFlbA (RGS), AfFluG, and AfBrlA, previously studied in Aspergillus nidulans. Expression analyses of gpaA, AfflbA, AffluG, AfbrlA, and AfwetA throughout the life cycle of A. fumigatus revealed that, while transcripts of AfflbA and AffluG accumulate constantly, the latter two downstream developmental regulators are specifically expressed during conidiation. Both loss-of-function AfflbA and dominant activating GpaAQ204L mutations resulted in reduced conidiation with increased hyphal proliferation, indicating that GpaA signaling activates vegetative growth while inhibiting conidiation. As GpaA is the primary target of AfFlbA, the dominant interfering GpaAG203R mutation suppressed reduced conidiation caused by loss of AfflbA function. These results corroborate the hypothesis that functions of G proteins and RGSs are conserved in aspergilli. We then examined functions of the two major developmental activators AfFluG and AfBrlA. While deletion of AfbrlA eliminated conidiation completely, null mutation of AffluG did not cause severe alterations in A. fumigatus sporulation in air-exposed culture, implying that, whereas the two aspergilli may have a common key downstream developmental activator, upstream mechanisms activating brlA may be distinct. Finally, both AffluG and AfflbA mutants showed reduced conidiation and delayed expression of AfbrlA in synchronized developmental induction, indicating that these upstream regulators contribute to the proper progression of conidiation.

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