TY - JOUR
T1 - Targeting a critical step in fungal hexosamine biosynthesis
AU - Lockhart, Deborah E. A.
AU - Stanley, Mathew
AU - Raimi, Olawale G.
AU - Robinson, David A.
AU - Boldovjakova, Dominika
AU - Squair, Daniel R.
AU - Ferenbach, Andrew T.
AU - Fang, Wenxia
AU - van Aalten, Daan M. F.
N1 - Acknowledgements
We wish to thank the Dundee Drug Discovery Unit for access to the Fragment library and the European Synchrotron Radiation Facility, Grenoble and Diamond Light Source, Oxford for time at the beamline. The assistance from Mr Martin Kierans, School of Life Sciences, University of Dundee with the Electron Microscopy is gratefully acknowledged.
Funding and additional information
This work was supported by a Wellcome Trust Postdoctoral Research Training Fellowship for Clinicians (WT105772/A/14/Z) to DL and an MRC Programme Grant (MR/M004139/1) to DMFvA. DB was funded by a University of Aberdeen Summer Research Scholarship.
PY - 2020/6/26
Y1 - 2020/6/26
N2 - Aspergillus fumigatus is a human opportunistic fungal pathogen whose cell wall protects it from the extracellular environment, including host defense responses. Chitin, an essential component of the fungal cell wall, is synthesized from UDP-GlcNAc produced in the hexosamine biosynthetic pathway. Because this pathway is critical for fungal cell wall integrity, the hexosamine biosynthesis enzymes represent potential targets of antifungal drugs. Here, we provide genetic and chemical evidence that glucosamine 6-phosphate N-acetyltransferase (Gna1), a key enzyme in this pathway, is an exploitable antifungal drug target. GNA1 deletion resulted in loss of fungal viability and disruption of the cell wall, phenotypes that could be rescued by exogenous GlcNAc, the product of the Gna1 enzyme. In a murine model of aspergillosis, the Dgna1 mutant strain exhibited attenuated virulence. Using a fragment-based approach, we discovered a small heterocyclic scaffold that binds proximal to the Gna1 active site and can be optimized to a selective sub-micromolar binder. Taken together, we have provided genetic, structural, and chemical evidence that Gna1 is anantifungal target in A. fumigatus.
AB - Aspergillus fumigatus is a human opportunistic fungal pathogen whose cell wall protects it from the extracellular environment, including host defense responses. Chitin, an essential component of the fungal cell wall, is synthesized from UDP-GlcNAc produced in the hexosamine biosynthetic pathway. Because this pathway is critical for fungal cell wall integrity, the hexosamine biosynthesis enzymes represent potential targets of antifungal drugs. Here, we provide genetic and chemical evidence that glucosamine 6-phosphate N-acetyltransferase (Gna1), a key enzyme in this pathway, is an exploitable antifungal drug target. GNA1 deletion resulted in loss of fungal viability and disruption of the cell wall, phenotypes that could be rescued by exogenous GlcNAc, the product of the Gna1 enzyme. In a murine model of aspergillosis, the Dgna1 mutant strain exhibited attenuated virulence. Using a fragment-based approach, we discovered a small heterocyclic scaffold that binds proximal to the Gna1 active site and can be optimized to a selective sub-micromolar binder. Taken together, we have provided genetic, structural, and chemical evidence that Gna1 is anantifungal target in A. fumigatus.
KW - fungi
KW - Aspergillus fumigatus
KW - cell wall
KW - glucosamine 6-phosphate N-acetyltransferase (Gna1)
KW - resistance
KW - fragment
KW - protein-protein interaction
KW - virulence factor
KW - chitin
KW - antifungal drug development
KW - X-ray crystallography
KW - ASPERGILLUS-FUMIGATUS
KW - PRACTICE GUIDELINES
KW - NIKKOMYCIN-Z
KW - STRESS-RESPONSE
KW - STRUCTURAL VALIDATION
KW - MURINE MODEL
KW - CELL-WALL
KW - GALLERIA-MELLONELLA LARVAE
KW - INHIBITORS
KW - INFECTIOUS-DISEASES SOCIETY
UR - http://www.scopus.com/inward/record.url?scp=85087253752&partnerID=8YFLogxK
U2 - 10.1074/jbc.RA120.012985
DO - 10.1074/jbc.RA120.012985
M3 - Article
C2 - 32341126
VL - 295
SP - 8678
EP - 8691
JO - The Journal of Biological Chemistry
JF - The Journal of Biological Chemistry
SN - 0021-9258
IS - 26
ER -
