title: Nitroxyl-mediated disruption of thiol proteins: inhibition of the yeast transcription factor Ace1.
abstract: Among the biologically and pharmacologically relevant nitrogen oxides, nitroxyl (HNO) remains one of the most poorly studied and least understood. Several previous reports indicate that thiols may be a primary target for the biological actions of HNO. However, the intimate details of the chemical interaction of HNO with biological thiols remain unestablished. Due to their ability to grow under a variety of conditions, the yeast Saccharomyces cerevisiae represents a unique and useful model system for examining the chemistry of HNO with thiol proteins in a whole-cell preparation. Herein, we have examined the effect of HNO on the thiol-containing, metal-responsive, yeast transcription factor Ace1 under a variety of cellular conditions as a means of delineating the chemistry of HNO interactions with this representative thiol protein. Using a reporter gene system, we find that HNO efficiently inhibits copper-dependent Ace1 activity. Moreover, this inhibition appears to be a result of a direct interaction between Ace1 thiols and HNO and not a result of any chemistry associated with HNO-derived species. Thus, this report indicates that thiol proteins can be a primary target of HNO biochemistry and that HNO-mediated thiol modification is likely due to a direct reaction of HNO.
authors.affiliation: Department of Pharmacology, UCLA School of Medicine, Center for the Health Sciences, Los Angeles, CA 90095-1735, USA.
authors.forename: Natalie M
authors.initials: NM
authors.lastname: Cook
authors.forename: Masaru
authors.initials: M
authors.lastname: Shinyashiki
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Jackson
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Leal
authors.forename: Jon M
authors.initials: JM
authors.lastname: Fukuto
mesh_terms: D003300:Copper / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D019281:Dimerization; D009573:Nitrites / Q000737:chemistry; D009589:Nitrogen Oxides / Q000737:chemistry* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000737:chemistry* / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism
chemical_list: C060256:CUP2 protein, S cerevisiae; D004268:DNA-Binding Proteins; D009573:Nitrites; D009589:Nitrogen Oxides; D029701:Saccharomyces cerevisiae Proteins; D013438:Sulfhydryl Compounds; D014157:Transcription Factors; C021229:oxyhyponitrite; D003300:Copper; C039900:nitroxyl