title: Identification of Multiple Cryptococcal Fungicidal Drug Targets by Combined Gene Dosing and Drug Affinity Responsive Target Stability Screening.
abstract: Cryptococcus neoformans is a pathogenic fungus that is responsible for up to half a million cases of meningitis globally, especially in immunocompromised individuals. Common fungistatic drugs, such as fluconazole, are less toxic for patients but have low efficacy for initial therapy of the disease. Effective therapy against the disease is provided by the fungicidal drug amphotericin B; however, due to its high toxicity and the difficulty in administering its intravenous formulation, it is imperative to find new therapies targeting the fungus. The antiparasitic drug bithionol has been recently identified as having potent fungicidal activity. In this study, we used a combined gene dosing and drug affinity responsive target stability (GD-DARTS) screen as well as protein modeling to identify a common drug binding site of bithionol within multiple NAD-dependent dehydrogenase drug targets. This combination genetic and proteomic method thus provides a powerful method for identifying novel fungicidal drug targets for further development.
  
  
  
  Cryptococcosis is a neglected fungal meningitis that causes approximately half a million deaths annually. The most effective antifungal agent, amphotericin B, was developed in the 1950s, and no effective medicine has been developed for this disease since that time. A key aspect of amphotericin B's effectiveness is thought to be because of its ability to kill the fungus (fungicidal activity), rather than just stop or slow its growth. The present study utilized a recently identified fungicidal agent, bithionol, to identify potential fungicidal drug targets that can be used in developing modern fungicidal agents. A combined protein and genetic analysis approach was used to identify a class of enzymes, dehydrogenases, that the fungus uses to maintain homeostasis with regard to sugar nutrients. Similarities in the drug target site were found that resulted in simultaneous inhibition and killing of the fungus by bithionol. These studies thus identify a common, multitarget site for antifungal development.
authors.affiliation: Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Yoon-Dong
authors.initials: YD
authors.lastname: Park
authors.affiliation: National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Antonio
authors.initials: A
authors.lastname: Salas
authors.affiliation: Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Avan
authors.initials: A
authors.lastname: Antia
authors.affiliation: Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Cindy
authors.initials: C
authors.lastname: Carvajal
authors.affiliation: National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Wang
authors.affiliation: National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.affiliation: Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Zhaojin
authors.initials: Z
authors.lastname: Meng
authors.affiliation: Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
authors.affiliation: National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Tawa
authors.affiliation: National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Jean
authors.initials: J
authors.lastname: Dehdashti
authors.affiliation: National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Microbiology Service, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Henderson
authors.affiliation: Microbiology Service, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Zelazny
authors.affiliation: Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA Section of Infectious Diseases, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA williamsonpr@mail.nih.gov.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Williamson
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001735:Bithionol / Q000494:pharmacology*; D003455:Cryptococcus neoformans / Q000187:drug effects* / Q000201:enzymology*; D003600:Cytosol / Q000737:chemistry; D004303:Dosage Compensation, Genetic; D062105:Molecular Docking Simulation; D010088:Oxidoreductases / Q000037:antagonists & inhibitors*
chemical_list: D000935:Antifungal Agents; D001735:Bithionol; D010088:Oxidoreductases