MRS6/YOR370C Summary Help

Standard Name MRS6 1
Systematic Name YOR370C
Alias MSI4 2
Feature Type ORF, Verified
Description Rab escort protein; forms a complex with the Ras-like small GTPase Ypt1p that is required for the prenylation of Ypt1p by protein geranylgeranyltransferase type II (Bet2p-Bet4p); sequence similarity to mammalian choroideraemia gene; relative distribution to the nucleus increases upon DNA replication stress (1, 3, 4, 5, 6 and see Summary Paragraph)
Name Description Mitochondrial RNA Splicing 7
Chromosomal Location
ChrXV:1030994 to 1029183 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All MRS6 GO evidence and references
  View Computational GO annotations for MRS6
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 2 genes
Classical genetics
reduction of function
Large-scale survey
reduction of function
67 total interaction(s) for 35 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 11
  • Affinity Capture-RNA: 5
  • Affinity Capture-Western: 6
  • Biochemical Activity: 5
  • Co-purification: 1
  • FRET: 2
  • PCA: 10
  • Reconstituted Complex: 2
  • Two-hybrid: 10

Genetic Interactions
  • Dosage Rescue: 10
  • Phenotypic Enhancement: 1
  • Phenotypic Suppression: 1
  • Synthetic Growth Defect: 2
  • Synthetic Lethality: 1

Expression Summary
Length (a.a.) 603
Molecular Weight (Da) 67,373
Isoelectric Point (pI) 4.47
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXV:1030994 to 1029183 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1812 1030994..1029183 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000005897

MRS6, the Rab Escort Protein (REP), is the accessory subunit (component A) of the type II (RAB-protein) geranylgeranyl transferase (GGTase II), while a stable heterodimer of Bet2p and Bet4p forms the catalytic component B. Mrs6p presents the substrate to the catalytic subunits. GGTase II (Bet2p, Bet4p, Mrs6p) is required for transport between the endoplasmic reticulum and the Golgi, and its role in that pathway seems to be in geranylgeranylating (prenylating) Ypt1p and Sec4p, small GTP-binding proteins that help mediate vesicular traffic. Blocking of prenylation leads to defects in the membrane attachment of Ypt1 and Sec4p (3, 8, 9). The type II GGTase is one of three prenyl transferases in yeast, the other two being farnesyl transferase and the type I GGTase (9, 10). MRS6 is similar to the human choroideraemia gene (1).

Last updated: 2010-05-18 Contact SGD

References cited on this page View Complete Literature Guide for MRS6
1) Waldherr M, et al.  (1993) MRS6--yeast homologue of the choroideraemia gene. Nat Genet 3(3):193-4
2) Fujimura K, et al.  (1994) The Saccharomyces cerevisiae MSI4 gene encodes the yeast counterpart of component A of Rab geranylgeranyltransferase. J Biol Chem 269(12):9205-12
3) Benito-Moreno RM, et al.  (1994) Mrs6p, the yeast homologue of the mammalian choroideraemia protein: immunological evidence for its function as the Ypt1p Rab escort protein. Curr Genet 27(1):23-5
4) Witter DJ and Poulter CD  (1996) Yeast geranylgeranyltransferase type-II: steady state kinetic studies of the recombinant enzyme. Biochemistry 35(32):10454-63
5) Miaczynska M, et al.  (1997) The yeast Rab escort protein binds intracellular membranes in vivo and in vitro. J Biol Chem 272(27):16972-7
6) Tkach JM, et al.  (2012) Dissecting DNA damage response pathways by analysing protein localization and abundance changes during DNA replication stress. Nat Cell Biol 14(9):966-76
7) Kreike J, et al.  (1986) Cloning of a nuclear gene MRS1 involved in the excision of a single group I intron (bI3) from the mitochondrial COB transcript in S. cerevisiae. Curr Genet 11(3):185-91
8) Jiang Y and Ferro-Novick S  (1994) Identification of yeast component A: reconstitution of the geranylgeranyltransferase that modifies Ypt1p and Sec4p. Proc Natl Acad Sci U S A 91(10):4377-81
9) Jiang Y, et al.  (1995) Characterization of yeast type-II geranylgeranyltransferase. Methods Enzymol 257:21-9
10) Jiang Y, et al.  (1993) Bet2p and Mad2p are components of a prenyltransferase that adds geranylgeranyl onto Ypt1p and Sec4p. Nature 366(6450):84-6