Cellular iron utilization is regulated by putative siderophore transporter FgSit1 not by free iron transporter in Fusarium graminearum.
This report investigated FgSit1, which encodes a putative ferrichrome transporter of Fusarium graminearum. The identity of the deduced amino acid sequence of FgSit1 with the amino acid sequence of ScArn1p, an FC-Fe(3+) transporter of Saccharomyces cerevisiae, was 51%; both the growth defect related to the Deltafet3Deltaarn1-4 strain of S. cerevisiae in an iron-depleted condition and the FC-Fe(3+) uptake activity were recovered upon the introduction of FgSit1 into the Deltafet3Deltaarn1-4 strain. Although ScArn1p was found in the late endosomal compartment in S. cerevisiae, FgSit1 was found on the plasma membrane in S. cerevisiae; when FgSit1 was expressed exogenously in S. cerevisiae, it showed greater FC-Fe(3+) uptake activity than did ScArn1p. Additionally, in F. graminearum FC-Fe(3+) uptake activity in the Deltafgsit1 strain was found to be one-fourth that of the wild-type. However, Fe(3+) uptake activity in the Deltafgsit1 strain was 5-fold higher than that of wild-type; the gene expression of FgFtr1, a putative iron transporter, was induced by the deletion of FgSit1, but was not induced by the deletion of FgSit2. Taken together, these results strongly suggest that FgSit1 encodes a putative FC-Fe(3+) transporter that mediates FC-Fe(3+) uptake using a different mechanism than ScArn1p and plays an important role in the regulation of cellular iron availability in F. graminearum.
Park
Yong-Sung
YS
School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul, Republic of Korea.
Kim
Tae-Hyoung
TH
Chang
Hyo-Ihl
HI
Sung
Ha-Chin
HC
Yun
Cheol-Won
CW
D000595:Amino Acid Sequence; D001692:Biological Transport; D015152:Blotting, Northern; D002462:Cell Membrane / Q000378:metabolism; D005291:Ferrichrome / Q000378:metabolism; D005670:Fusarium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007501:Iron / Q000378:metabolism / Q000493:pharmacokinetics* / Q000494:pharmacology; D026901:Membrane Transport Proteins / Q000235:genetics / Q000502:physiology*; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009154:Mutation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D017262:Siderophores / Q000378:metabolism*; D014170:Transformation, Genetic
D026901:Membrane Transport Proteins; D011993:Recombinant Fusion Proteins; D017262:Siderophores; D049452:Green Fluorescent Proteins; D005291:Ferrichrome; D007501:Iron