title: Glycerophosphocholine utilization by Candida albicans: role of the Git3 transporter in virulence.
abstract: Candida albicans contains four ORFs (GIT1,2,3,4) predicted to encode proteins involved in the transport of glycerophosphodiester metabolites. Previously, we reported that Git1, encoded by ORF 19.34, is responsible for the transport of intact glycerophosphoinositol but not glycerophosphocholine (GroPCho). Here, we report that a strain lacking both GIT3 (ORF 19.1979) and GIT4 (ORF 19.1980) is unable to transport [(3)H]GroPCho into the cell. In the absence of a GroPCho transporter, C. albicans can utilize GroPCho via a mechanism involving extracellular hydrolysis. Upon reintegration of either GIT3 or GIT4 into the genome, measurable uptake of [(3)H]GroPCho is observed. Transport assays and kinetic analyses indicate that Git3 has the greater transport velocity. We present evidence that GDE1 (ORF 19.3936) codes for an enzyme with glycerophosphodiesterase activity against GroPCho. Homozygous deletion of GDE1 results in a buildup of internal GroPCho that is restored to wild type levels by reintegration of GDE1 into the genome. The transcriptional regulator, Pho4, is shown to regulate the expression of GIT3, GIT4, and GDE1. Finally, Git3 is shown to be required for full virulence in a mouse model of disseminated candidiasis, and Git3 sequence orthologs are present in other pathogenic Candida species. In summary, we have characterized multiple aspects of GroPCho utilization by C. albicans and have demonstrated that GroPCho transport plays a key role in the growth of the organism in the host.
authors.affiliation: Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Bishop
authors.affiliation: Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
authors.forename: Shantanu
authors.initials: S
authors.lastname: Ganguly
authors.affiliation: Division of Infectious Disease, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California 90502.
authors.forename: Norma V
authors.initials: NV
authors.lastname: Solis
authors.affiliation: Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Cooley
authors.affiliation: Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Jensen-Seaman
authors.affiliation: Division of Infectious Disease, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California 90502; David Geffen School of Medicine at UCLA, Los Angeles, California 90024.
authors.forename: Scott G
authors.initials: SG
authors.lastname: Filler
authors.affiliation: Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Mitchell
authors.affiliation: Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282. Electronic address: pattonvogt@duq.edu.
authors.forename: Jana
authors.initials: J
authors.lastname: Patton-Vogt
mesh_terms: D000818:Animals; D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism*; D002176:Candida albicans / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D002177:Candidiasis / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D017136:Ion Transport / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D016366:Open Reading Frames; D010742:Phospholipid Ethers / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D027321:Anion Transport Proteins; D005656:Fungal Proteins; D010742:Phospholipid Ethers; D014157:Transcription Factors; D037521:Virulence Factors
keywords: Candida albicans; Glycerophosphocholine; Pathogenesis; Phosphatidylcholine; Phospholipid Metabolite; Phospholipid Turnover; Transport; Yeast Genetics