RFT1/YBL020W Summary Help

Standard Name RFT1 1
Systematic Name YBL020W
Feature Type ORF, Verified
Description Membrane protein required for translocation of Man5GlcNac2-PP-Dol; required for translocation of Man5GlcNac2-PP-Dol from the cytoplasmic side to the lumenal side of the ER membrane but is not the flippase; mutation is suppressed by expression of human p53 protein; essential gene (1, 2, 3, 4, 5 and see Summary Paragraph)
Name Description Requiring Fifty-Three 1
Chromosomal Location
ChrII:182401 to 184125 | ORF Map | GBrowse
Gene Ontology Annotations All RFT1 GO evidence and references
  View Computational GO annotations for RFT1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 2 genes
Classical genetics
Large-scale survey
reduction of function
29 total interaction(s) for 27 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 5
  • Affinity Capture-Western: 1
  • PCA: 2
  • Two-hybrid: 2

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 5
  • Phenotypic Enhancement: 2
  • Positive Genetic: 2
  • Synthetic Growth Defect: 6
  • Synthetic Lethality: 3

Expression Summary
Length (a.a.) 574
Molecular Weight (Da) 66,210
Isoelectric Point (pI) 9.94
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrII:182401 to 184125 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1997-01-28
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1725 182401..184125 2011-02-03 1997-01-28
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) | TCDB | UniProtKB
Primary SGDIDS000000116

During N-linked glycosylation of proteins, oligosaccharide chains are assembled on the carrier molecule dolichyl pyrophosphate in the following order: 2 molecules of N-acetylglucosamine (GlcNAc), 9 molecules of mannose, and 3 molecules of glucose. These 14-residue oligosaccharide cores are then transferred to asparagine residues on nascent polypeptide chains in the endoplasmic reticulum (ER). As proteins progress through the Golgi apparatus, the oligosaccharide cores are modified by trimming and extension to generate a diverse array of glycosylated proteins (reviewed in 6, 7).

The first seven saccharide moieties are added to dolichyl phosphate on the cytosolic side of the ER, and the last seven are added in the lumen of the ER. Rft1p is required for translocation of the nascent lipid-linked oligosaccharide (LLO) from the cytosolic to the lumenal face of the ER membrane (2), but does not co-purify with the flippase activity (4, 3). Moreover, Rft1p depletion does not affect transbilayer movement of Man5GlcNac2-P-P-Dol in sealed microsomal fractions (5). RFT1 is essential (1, 2), but conditional mutants accumulate LLO's with five mannose residues (2). Although they share no homology, RFT1 ("Requires Fifty-Three") was originally isolated as a partial loss-of-function mutation suppressed by introduction of human p53 (OMIM) (1) but p53 does not complement deletion of RFT1.

Last updated: 2005-07-12 Contact SGD

References cited on this page View Complete Literature Guide for RFT1
1) Koerte A, et al.  (1995) Suppression of the yeast mutation rft1-1 by human p53. J Biol Chem 270(38):22556-64
2) Helenius J, et al.  (2002) Translocation of lipid-linked oligosaccharides across the ER membrane requires Rft1 protein. Nature 415(6870):447-50
3) Sanyal S, et al.  (2008) Distinct flippases translocate glycerophospholipids and oligosaccharide diphosphate dolichols across the endoplasmic reticulum. Biochemistry 47(30):7937-46
4) Frank CG, et al.  (2008) Does Rft1 flip an N-glycan lipid precursor? Nature 454(7204):E3-4; discussion E4-5
5) Rush JS, et al.  (2009) Suppression of Rft1 Expression Does Not Impair the Transbilayer Movement of Man5GlcNAc2-P-P-Dolichol in Sealed Microsomes from Yeast. J Biol Chem 284(30):19835-42
6) Herscovics A and Orlean P  (1993) Glycoprotein biosynthesis in yeast. FASEB J 7(6):540-50
7) Burda P and Aebi M  (1999) The dolichol pathway of N-linked glycosylation. Biochim Biophys Acta 1426(2):239-57