Trans-dominant
mutations in two members of the GPR1/FUN34/YAAH protein family
(YNR002C, YCR010C) effect acetic acid sensitivity in Saccharomyces
cerevisiae.
Margret Kuschel (1),
Kristina Creuzburg (1), Stefan Hohmann (2), Gerold Barth (1)
(1) Institute of Microbiology, Technical University Dresden, Mommsenstr. 13,
Dresden, 01062, Germany (Kuschel@rcs.urz.tu-dresden.de); (2) Department of Cell
and Molecular Biology/ Microbiology, Göteborg University, Box 462, S-40530
Göteborg, Sweden, Phone: +46-31-7732595, Fax: +46-31-7732599,
(hohmann@gmm.gu.se)
Single base exchanges in the GPR1 (glyoxylate pathway regulator) gene of Yarrowia lipolytica act trans-dominant and cause high sensitivity to acetic acid (1). The GPR1 gene encodes a intrinsic membrane protein and its deletion causes a slower adaptation of Y. lipolytica cells to acetic acid containing media (2). Gpr1p is a member of the GPR1/FUN34/yaaH family of proteins which are highly conserved in pro- and eukaryotes. Saccharomyces cerevisiae contains three proteins (Ynr002cp (Fun34p), Ycr010cp, Ydr384cp), highly homologous to Gpr1p. Expression of these genes is increased in cells of old colonies (10.5 - 12d). Deletion mutants show a reduced secretion of ammonium (3). Expression of two YlGPR1 mutant alleles in S. c. caused also a trans-dominant sensitivity to acetic acid. We performed site specific mutations in YCR010c and FUN34 to test whether similar mutations in the homologues genes of S. cerevisiae have the same effect. Strains harbouring one of these mutated genes grew normally on glucose but could not grow on acetic acid. Our further studies have shown that YCR010c, YNR002c and YDR384c are differently expressed in glucose containing media and that their expression is differently induced by several carbon sources. These data suggest that these proteins may have divergent physiological functions during growth on different carbon sources. 1) Tzschoppe et al. (1999) Yeast 15, 1645-1656 2) Augstein et al (2003) Microbiology 149, in press 3) Palková et al. (2002) Mol Biol Cell 13, 3901-3914