The yeast protein Mrs6p, a homologue of the rabGDI and human choroideraemia proteins, affects cytoplasmic and mitochondrial functions.
MRS6 is a newly-identified gene in the yeast Saccharomyces cerevisiae. Its product Mrs6p shows significant homology to the mammalian GDP dissociation inhibitor (GDI) of Rab/Ypt-type small G proteins and to the human choroideraemia protein (CHM), the component A of Rab-specific GGTase II. The interaction of Mrs6p with G proteins is indicated by our observation that the MRS6 gene suppresses the effect of a temperature-sensitive ypt1 mutation. Disruption of the MRS6 gene is lethal to haploid yeast cells. This is consistent with the notion that Mrs6p is interacting with Rab/Ypt-type small G proteins, which are known to have essential functions in vesicular transport. Unexpectedly, the MRS6 gene product also affects mitochondrial functions as revealed by the facts that high-copy numbers of MRS6 (1) suppress the pet- phenotype of mrs2-1 mutant strains and (2) cause a weak pet- phenotype in wild-type strains. We conclude from these results that the MRS6 gene product has a vital function in connection with Rab/Ypt-type proteins in the cytoplasm and, in addition, affects mitochondrial functions.
Ragnini
A
A
Vienna Biocenter, Institute of Microbiology and Genetics, University of Vienna, Austria.
Teply
R
R
Waldherr
M
M
Voskova
A
A
Schweyen
R J
RJ
D048868:Adaptor Proteins, Signal Transducing; D019883:Alkyl and Aryl Transferases; D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D003593:Cytoplasm / Q000502:physiology; D004271:DNA, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000235:genetics; D005800:Genes, Fungal; D016153:Genes, Suppressor; D020730:Guanine Nucleotide Dissociation Inhibitors; D006801:Humans; D008928:Mitochondria / Q000502:physiology; D008969:Molecular Sequence Data; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D020691:rab GTP-Binding Proteins
D048868:Adaptor Proteins, Signal Transducing; C081787:CHM protein, human; D002352:Carrier Proteins; D004271:DNA, Fungal; D005656:Fungal Proteins; C086796:GDP dissociation inhibitor 1; D020730:Guanine Nucleotide Dissociation Inhibitors; C092439:MRS6 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D019883:Alkyl and Aryl Transferases; D019204:GTP-Binding Proteins; D020691:rab GTP-Binding Proteins