title: Polymorphism of Saccharomyces cerevisiae aquaporins.
abstract: Aquaporin water channels facilitate the transmembrane diffusion of water and higher organisms possess a large number of isoforms. The genome of the yeast Saccharomyces cerevisiae contains two highly similar aquaporin genes, AQY1 and AQY2. AQY1 has been shown to encode a functional water channel but only in certain laboratory strains. Here we show that the AQY2 gene is interrupted by an 11 bp deletion in 23 of the 27 laboratory strains tested, with the exception of strains from the sigma 1278b background, which also exhibit a functional Aqy1p. However, although the AQY2 gene from sigma 1278b is highly homologous to functional aquaporins, we did not observe Aqy2p-mediated water transport in Xenopus oocytes. A survey of 52 yeast strains revealed that all industrial and wild yeasts carry the allele encoding a functional Aqy1p, while none of these strains appear to have a functional Aqy2p. We conclude that natural and industrial conditions provide selective pressure to maintain AQY1 but apparently not AQY2.
authors.affiliation: Department of Cell and Molecular Biology, Microbiology, Göteborg University, Box 462, SE-40530 Göteborg, Sweden.
authors.forename: V
authors.initials: V
authors.lastname: Laizé
authors.forename: F
authors.initials: F
authors.lastname: Tacnet
authors.forename: P
authors.initials: P
authors.lastname: Ripoche
authors.forename: S
authors.initials: S
authors.lastname: Hohmann
mesh_terms: D000595:Amino Acid Sequence; D020346:Aquaporins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: C115153:AQY1 protein, S cerevisiae; C422454:AQY2 protein, S cerevisiae; D020346:Aquaporins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins