title: HcZrt2, a zinc responsive gene, is indispensable for the survival of Histoplasma capsulatum in vivo.
abstract: Histoplasma capsulatum (Hc) exists in the soil and is capable of adapting to the shift in environment during infection to ensure survival. Yeast encounter a restrictive host environment low in nutrients such as zinc. In this study we functionally analyzed a putative zinc regulated transporter, HcZrt2, in zinc limiting conditions by complementation of HcZrt2 and gene knockdown through RNA interference (RNAi). Complementation analysis demonstrated HcZrt2's ability to functionally replace the characterized Saccharomyces cerevisiae zinc plasma membrane transporters Zrt1 and Zrt2 in zinc deficient medium. Gene silencing revealed that HcZrt2 is essential for growth in zinc deficient medium and plays a role in zinc accumulation. Fungal burden was reduced in mice infected with HcZrt2 silenced strains compared to a control strain. Sixty-seven percent of mice infected with a lethal dose of HcZrt2-RNAi#1 survived, and 100% of mice infected with HcZrt2-RNAi#2 withstood lethal infection. Our data suggest that HcZrt2 is a vital part of zinc homeostasis and essential for the pathogenesis of histoplasmosis.
authors.affiliation: Department of Molecular Genetics, Biochemistry and Microbiology.
authors.forename: Jessica
authors.initials: J
authors.lastname: Dade
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases.
authors.forename: Juwen C
authors.initials: JC
authors.lastname: DuBois
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases.
authors.forename: Rajamouli
authors.initials: R
authors.lastname: Pasula
authors.affiliation: Department of Chemistry University of Cincinnati, Cincinnati OH 45267.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Donnell
authors.affiliation: Department of Chemistry University of Cincinnati, Cincinnati OH 45267.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Caruso
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases Cincinnati VA Medical Center, Cincinnati Ohio alan.smulian@uc.edu.
authors.forename: A George
authors.initials: AG
authors.lastname: Smulian
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases Cincinnati VA Medical Center, Cincinnati Ohio.
authors.forename: George S
authors.initials: GS
authors.lastname: Deepe
mesh_terms: D000818:Animals; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D002470:Cell Survival; D015169:Colony Count, Microbial; D003470:Culture Media / Q000737:chemistry; D004195:Disease Models, Animal; D017353:Gene Deletion; D055785:Gene Knockdown Techniques; D005816:Genetic Complementation Test; D006658:Histoplasma / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D006660:Histoplasmosis / Q000382:microbiology*; D008297:Male; D008810:Mice, Inbred C57BL; D034622:RNA Interference; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D016019:Survival Analysis; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D027682:Cation Transport Proteins; D003470:Culture Media; D037521:Virulence Factors; D015032:Zinc
keywords: Histoplasma capsulatum; RNAi; TPEN; zinc deficiency