title: Chemical Genomics-Based Antifungal Drug Discovery: Targeting Glycosylphosphatidylinositol (GPI) Precursor Biosynthesis.
abstract: Steadily increasing antifungal drug resistance and persistent high rates of fungal-associated mortality highlight the dire need for the development of novel antifungals. Characterization of inhibitors of one enzyme in the GPI anchor pathway, Gwt1, has generated interest in the exploration of targets in this pathway for further study. Utilizing a chemical genomics-based screening platform referred to as the Candida albicans fitness test (CaFT), we have identified novel inhibitors of Gwt1 and a second enzyme in the glycosylphosphatidylinositol (GPI) cell wall anchor pathway, Mcd4. We further validate these targets using the model fungal organism Saccharomyces cerevisiae and demonstrate the utility of using the facile toolbox that has been compiled in this species to further explore target specific biology. Using these compounds as probes, we demonstrate that inhibition of Mcd4 as well as Gwt1 blocks the growth of a broad spectrum of fungal pathogens and exposes key elicitors of pathogen recognition. Interestingly, a strong chemical synergy is also observed by combining Gwt1 and Mcd4 inhibitors, mirroring the demonstrated synthetic lethality of combining conditional mutants of GWT1 and MCD4. We further demonstrate that the Mcd4 inhibitor M720 is efficacious in a murine infection model of systemic candidiasis. Our results establish Mcd4 as a promising antifungal target and confirm the GPI cell wall anchor synthesis pathway as a promising antifungal target area by demonstrating that effects of inhibiting it are more general than previously recognized.
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Mann
authors.affiliation: Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, United States.|Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: McLellan
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Sandra
authors.initials: S
authors.lastname: Koseoglu
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Qian
authors.initials: Q
authors.lastname: Si
authors.affiliation: Banting and Best Department of Medical Research, Terrance Donnally Centre of Cellular and Biomedical Research, University of Toronto , Toronto, Ontario, Canada.
authors.forename: Elena
authors.initials: E
authors.lastname: Kuzmin
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Amy
authors.initials: A
authors.lastname: Flattery
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Guy
authors.initials: G
authors.lastname: Harris
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Xinwei
authors.initials: X
authors.lastname: Sher
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Murgolo
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Kristine
authors.initials: K
authors.lastname: Devito
authors.affiliation: Fundación Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucı́a, Medina, Parque Tecnológico de Ciencias de la Salud , Avenida Conocimiento 34, 18016 Grenada, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: de Pedro
authors.affiliation: Fundación Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucı́a, Medina, Parque Tecnológico de Ciencias de la Salud , Avenida Conocimiento 34, 18016 Grenada, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: Genilloud
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Jennifer Nielsen
authors.initials: JN
authors.lastname: Kahn
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Banting and Best Department of Medical Research, Terrance Donnally Centre of Cellular and Biomedical Research, University of Toronto , Toronto, Ontario, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Costanzo
authors.affiliation: Banting and Best Department of Medical Research, Terrance Donnally Centre of Cellular and Biomedical Research, University of Toronto , Toronto, Ontario, Canada.
authors.forename: Charlie
authors.initials: C
authors.lastname: Boone
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Charles G
authors.initials: CG
authors.lastname: Garlisi
authors.affiliation: Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, United States.|Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Susan
authors.initials: S
authors.lastname: Lindquist
authors.affiliation: Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
authors.forename: Terry
authors.initials: T
authors.lastname: Roemer
keywords: Candida albicans fitness test; GPI; GWT1; MCD4; antifungal; chemical biology; glycosylphosphatidylinositol; natural product; next-generation sequencing; yeast cell wall