title: Genomewide screen reveals a wide regulatory network for di/tripeptide utilization in Saccharomyces cerevisiae.
abstract: Small peptides of two to six residues serve as important sources of amino acids and nitrogen required for growth by a variety of organisms. In the yeast Saccharomyces cerevisiae, the membrane transport protein Ptr2p, encoded by PTR2, mediates the uptake of di/tripeptides. To identify genes involved in regulation of dipeptide utilization, we performed a systematic, functional examination of this process in a haploid, nonessential, single-gene deletion mutant library. We have identified 103 candidate genes: 57 genes whose deletion decreased dipeptide utilization and 46 genes whose deletion enhanced dipeptide utilization. On the basis of Ptr2p-GFP expression studies, together with PTR2 expression analysis and dipeptide uptake assays, 42 genes were ascribed to the regulation of PTR2 expression, 37 genes were involved in Ptr2p localization, and 24 genes did not apparently affect Ptr2p-GFP expression or localization. The 103 genes regulating dipeptide utilization were distributed among most of the Gene Ontology functional categories, indicating a very wide regulatory network involved in transport and utilization of dipeptides in yeast. It is anticipated that further characterization of how these genes affect peptide utilization should add new insights into the global mechanisms of regulation of transport systems in general and peptide utilization in particular.
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville 37996-0845, USA.
authors.forename: Houjian
authors.initials: H
authors.lastname: Cai
authors.forename: Sarah
authors.initials: S
authors.lastname: Kauffman
authors.forename: Fred
authors.initials: F
authors.lastname: Naider
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Becker
mesh_terms: D002172:Canavanine / Q000378:metabolism; D004151:Dipeptides / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D005800:Genes, Fungal; D017930:Genes, Reporter; D016681:Genome, Fungal; D026901:Membrane Transport Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D009842:Oligopeptides / Q000235:genetics / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology
chemical_list: D004151:Dipeptides; D026901:Membrane Transport Proteins; D009842:Oligopeptides; C093495:PTR2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D002172:Canavanine; C092477:PMA1 protein, S cerevisiae; D006180:Proton-Translocating ATPases