title: Siderophore uptake and use by the yeast Saccharomyces cerevisiae.
abstract: The non-reductive uptake of several siderophores (ferrioxamine B, ferrichrome, triacetylfusarinine C and ferricrocin) by various strains of Saccharomyces cerevisiae was studied. Several aspects of siderophore transport were examined, including specificity of transport, regulation of transport and intracellular localization of the ferri-siderophores. Ferrioxamine B was taken up preferentially via the products of the SIT1 gene and triacetylfusarinine C by the TAF1 gene product, but the specificity was not absolute. Ferrichrome and ferricrocin uptake was not dependent on a single major facilitator superfamily (MFS) gene product. The apparent specificity of transport was strongly dependent on the genetic background of the cells. Non-reductive uptake of siderophores was induced under more stringent conditions (of iron deprivation) than was the reductive uptake of ferric citrate. Regulation of transport depended on the transcriptional factors Aft1 and Tup1/Ssn6. Cells disrupted for the TUP1 or SSN6 genes were constitutively derepressed for the uptake of ferrichrome, ferricrocin or ferrioxamine B, but not for the uptake of triacetylfusarinine C. Cells bearing the AFT1(up) mutation accumulated large amounts of ferric siderophores. Intracellular decomplexation of the siderophores occurred when transcription of the AFT1(up) gene was repressed. Ferrioxamine B and ferrichrome seemed to accumulate in an endosomal compartment, as shown by biochemical studies and by confocal microscopy study of cells loaded with a fluorescent derivative of ferrichrome. Endocytosis was, however, not involved in the non-reductive uptake of siderophores.
authors.affiliation: Laboratoire d'Ingénierie des Protéines et Contrôle Métabolique, Institut Jacques Monod, Tour 43, Université Paris 7/Paris 6, 2 place Jussieu, 75251 Paris cedex 05, France1.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Lesuisse
authors.affiliation: Laboratoire d'Ingénierie des Protéines et Contrôle Métabolique, Institut Jacques Monod, Tour 43, Université Paris 7/Paris 6, 2 place Jussieu, 75251 Paris cedex 05, France1.
authors.forename: Pierre-Louis
authors.initials: PL
authors.lastname: Blaiseau
authors.affiliation: University of Pennsylvania, Department of Medicine, Division of Hematology/Oncology, BRBII Room 731, 431 Curie Blvd, Philadelphia, PA 19104, USA2.
authors.forename: Andrew
authors.initials: A
authors.lastname: Dancis
authors.affiliation: Laboratoire d'Ingénierie des Protéines et Contrôle Métabolique, Institut Jacques Monod, Tour 43, Université Paris 7/Paris 6, 2 place Jussieu, 75251 Paris cedex 05, France1.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Camadro
mesh_terms: D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D005290:Ferric Compounds / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D007501:Iron / Q000378:metabolism; D026901:Membrane Transport Proteins; D009687:Nuclear Proteins; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017262:Siderophores / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: C090297:AFT1 protein, S cerevisiae; C409889:ARN2 protein, S cerevisiae; C065455:CYC8 protein, S cerevisiae; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D005290:Ferric Compounds; D005656:Fungal Proteins; D026901:Membrane Transport Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D017262:Siderophores; C066502:TUP1 protein, S cerevisiae; D014157:Transcription Factors; D007501:Iron; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; C104343:SIT4 protein, S cerevisiae