title: Tpr1, a Schizosaccharomyces pombe protein involved in potassium transport.
abstract: The Schizosaccharomyces pombe Tpr1 was isolated as suppressor of the Saccharomyces cerevisiae Delta trk1,2 potassium uptake deficient phenotype. Tpr1, for tetratrico peptide repeat, encodes a 1039 amino acid residues protein with several reiterated TPR units displaying significant homology to p150(TSP), a recently identified phosphoprotein of mouse, to S. cerevisiae CTR9 and to related sequences of human, Caenorhabditis elegans, Methanoccocus jannaschii and Arabidopsis thaliana. Expression of Tpr1 restored growth on 0.2 mM K(+) media, induced K(+) transport with a K(T) of 4.6 mM and resumed inward currents of -90 pA at -250 mV (pH 7.2) conducting K(+) and other alkali-metal ions. The tetratrico peptide repeat is a degenerate motif of 34 amino acids that is repeated several times within TPR-containing proteins and has been suggested to mediate protein-protein interactions. The sequence and putative binding properties of Tpr1 suggest the protein unlikely as transporter but involved in the enhancement of K(+) uptake via conventional carriers.
authors.affiliation: Botanisches Institut der Universität Bonn, Kirschallee 1, 53115, Bonn, Germany. H.Lichtenberg@uni-bonn.de
authors.forename: H
authors.initials: H
authors.lastname: Lichtenberg
authors.forename: M
authors.initials: M
authors.lastname: Heyer
authors.forename: M
authors.initials: M
authors.lastname: Höfer
mesh_terms: D019747:Aldose-Ketose Isomerases; D000818:Animals; D017360:Arabidopsis / Q000737:chemistry; D001692:Biological Transport / Q000187:drug effects; D017173:Caenorhabditis elegans / Q000737:chemistry; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D005656:Fungal Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D005816:Genetic Complementation Test; D006801:Humans; D017017:Methanococcus / Q000737:chemistry; D051379:Mice; D008969:Molecular Sequence Data; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000737:chemistry* / Q000378:metabolism; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid
chemical_list: D005656:Fungal Proteins; D015221:Potassium Channels; D029701:Saccharomyces cerevisiae Proteins; D004024:Dicyclohexylcarbodiimide; D019747:Aldose-Ketose Isomerases; C490353:TRP1 protein, S cerevisiae; D011188:Potassium