The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

MRS6  -  Mrs6p

Saccharomyces cerevisiae S288c

Synonyms: MSI4, REP, Rab escort protein, Rab proteins geranylgeranyltransferase component A, YOR370C
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of MRS6

  • The yeast MRS6 gene encodes a protein that is approximately 30% identical to the choroideremia gene product [1].

High impact information on MRS6

  • We propose that the REP loci constitute a copy control system that overrides normal cellular restriction on plasmid replication and amplifies the plasmid when copy number is low [2].
  • Rab escort proteins (REP) 1 and 2 are closely related mammalian proteins required for prenylation of newly synthesized Rab GTPases by the cytosolic heterodimeric Rab geranylgeranyl transferase II complex (RabGG transferase) [3].
  • Although REP and GDI share common Rab-binding properties, GDI cannot assist in Rab prenylation and REP cannot retrieve Rab proteins from the membranes [4].
  • After delivery to the membrane by the REP-Rab complex, subsequent recycling to the cytosol requires the REP-related guanine-nucleotide-dissociation-inhibitor (GDI) [4].
  • Molecular evolution of the Rab-escort-protein/guanine-nucleotide-dissociation-inhibitor superfamily [4].

Biological context of MRS6

  • The only known yeast homologue of the choroideremia gene product is encoded by an essential gene called MRS6 [5].
  • Disruption of the MRS6 gene is lethal to haploid yeast cells [6].
  • 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 [6].
  • Here, we report the characterization of a yeast REP mutant, mrs6-2, in which reduced prenylation of Ypt proteins occurs even at the permissive temperature [7].
  • A gene disruption experiment showed that MSI4 is essential for cell growth [8].

Anatomical context of MRS6


Associations of MRS6 with chemical compounds

  • A point mutant allele of AthREP with arginine at this position complemented the yeast REP mutation, while wild-type AthREP did not [10].
  • We found that a conserved arginine residue, R195, known to be crucial for yeast REP function, is substituted by an asparagine or threonine residue in angiosperm REPs [10].
  • Prenylated Ypt1p obtained after incubation of Ypt1p with PGGTase-II, Msi4p, and geranylgeranyl diphosphate was digested with trypsin [11].
  • Recombinant Msi4p with an N-terminal polyhistidine leader was purified on a Ni(2+)-Sepharose column, followed by gel filtration and ion exchange chromatography [11].
  • In yeast estrogen receptor transcription assay, both EEP and REP were found to be estrogenic with EC(50) values of 9.48, and 8.55 microg/ml, respectively [12].

Regulatory relationships of MRS6

  • Here we characterize an antiserum directed against Mrs6p and show that it specifically inhibits the geranylation of the YPT1 protein in an in vitro assay [13].

Other interactions of MRS6

  • To investigate its functions further, we constructed a strain whose MSI4 is driven by the GAL1 promoter [8].
  • We describe the isolation of MSI4 as a multicopy suppressor of ira1 (inhibitory regulator of Ras) [8].

Analytical, diagnostic and therapeutic context of MRS6

  • We used oligonucleotide primers that are complementary to (i) intron splice sites, (ii) REP and (iii) ERIC elements to produce PCR fingerprints that display specific patterns between the different yeast species [14].


  1. Identification of yeast component A: reconstitution of the geranylgeranyltransferase that modifies Ypt1p and Sec4p. Jiang, Y., Ferro-Novick, S. Proc. Natl. Acad. Sci. U.S.A. (1994) [Pubmed]
  2. The yeast plasmid 2mu circle encodes components required for its high copy propagation. Jayaram, M., Li, Y.Y., Broach, J.R. Cell (1983) [Pubmed]
  3. Molecular basis for Rab prenylation. Alory, C., Balch, W.E. J. Cell Biol. (2000) [Pubmed]
  4. Molecular evolution of the Rab-escort-protein/guanine-nucleotide-dissociation-inhibitor superfamily. Alory, C., Balch, W.E. Mol. Biol. Cell (2003) [Pubmed]
  5. Amino- and carboxy-terminal domains of the yeast Rab escort protein are both required for binding of Ypt small G proteins. Bauer, B.E., Lorenzetti, S., Miaczynska, M., Bui, D.M., Schweyen, R.J., Ragnini, A. Mol. Biol. Cell (1996) [Pubmed]
  6. The yeast protein Mrs6p, a homologue of the rabGDI and human choroideraemia proteins, affects cytoplasmic and mitochondrial functions. Ragnini, A., Teply, R., Waldherr, M., Voskova, A., Schweyen, R.J. Curr. Genet. (1994) [Pubmed]
  7. Low levels of Ypt protein prenylation cause vesicle polarization defects and thermosensitive growth that can be suppressed by genes involved in cell wall maintenance. Bialek-Wyrzykowska, U., Bauer, B.E., Wagner, W., Kohlwein, S.D., Schweyen, R.J., Ragnini, A. Mol. Microbiol. (2000) [Pubmed]
  8. The Saccharomyces cerevisiae MSI4 gene encodes the yeast counterpart of component A of Rab geranylgeranyltransferase. Fujimura, K., Tanaka, K., Nakano, A., Toh-e, A. J. Biol. Chem. (1994) [Pubmed]
  9. The yeast Rab escort protein binds intracellular membranes in vivo and in vitro. Miaczynska, M., Lorenzetti, S., Bialek, U., Benito-Moreno, R.M., Schweyen, R.J., Ragnini, A. J. Biol. Chem. (1997) [Pubmed]
  10. A specific feature of the angiosperm Rab escort protein (REP) and evolution of the REP/GDI superfamily. Hála, M., Eliás, M., Zárský, V. J. Mol. Biol. (2005) [Pubmed]
  11. Yeast geranylgeranyltransferase type-II: steady state kinetic studies of the recombinant enzyme. Witter, D.J., Poulter, C.D. Biochemistry (1996) [Pubmed]
  12. Estrogenic effects of ethanol and ether extracts of propolis. Song, Y.S., Jin, C., Jung, K.J., Park, E.H. Journal of ethnopharmacology. (2002) [Pubmed]
  13. Mrs6p, the yeast homologue of the mammalian choroideraemia protein: immunological evidence for its function as the Ypt1p Rab escort protein. Benito-Moreno, R.M., Miaczynska, M., Bauer, B.E., Schweyen, R.J., Ragnini, A. Curr. Genet. (1994) [Pubmed]
  14. New PCR-based methods for yeast identification. Hierro, N., González, A., Mas, A., Guillamón, J.M. J. Appl. Microbiol. (2004) [Pubmed]
WikiGenes - Universities