title: Association of putative ammonium exporters Ato with detergent-resistant compartments of plasma membrane during yeast colony development: pH affects Ato1p localisation in patches.
abstract: It was proposed that Ato1p, Ato2p and Ato3p have a role in ammonia production by Saccharomyces cerevisiae colonies (Palkova et al., Mol Biol Cell 13: 3901-3914, 2002). In this study, we show that all three Ato proteins localise to the plasma membrane and their appearance correlates with the beginning of ammonia release. The expression of ATO genes is controlled by ammonia. All three Ato-GFP proteins associate with detergent-resistant membranes; two of them, Ato1p-GFP and Ato3p-GFP, localise to patches visible under the fluorescence microscope. In contrast with Ato3p-GFP which forms stable patches, the formation of those of Ato1p-GFP is pH dependent. Ato1p-GFP patches form at pH above 6 and they disappear at pH 5 or lower. Both changes, Ato1p-GFP clustering and patches spreading are reversible. The Ato1p-GFP spreading at low pH is independent on endocytosis. These data suggest that besides the ammonia induction of Ato protein synthesis, pH may rapidly regulate Ato1p function.
authors: Department of Genetics and Microbiology, Charles University in Prague, Vinicná 5, 128 44 Prague 2, Czech Republic.
authors: Markéta
authors: M
authors: Ricicová
authors: Helena
authors: H
authors: Kucerová
authors: Libuse
authors: L
authors: Váchová
authors: Zdena
authors: Z
authors: Palková
mesh_terms: D000641:Ammonia / Q000378:metabolism; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000378:metabolism*; D003902:Detergents / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008565:Membrane Proteins / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism*; D021381:Protein Transport; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: C520069:ATO1 protein, S cerevisiae; C089361:ATO2 protein, S cerevisiae; C479828:ATO3 protein, S cerevisiae; D003902:Detergents; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D000644:Quaternary Ammonium Compounds; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; D000641:Ammonia