Defective RFT1 does not flip the N-glycan precursor

Stable Identifier
Reaction [transition]
Homo sapiens
Locations in the PathwayBrowser
SVG |   | PPTX  | SBGN
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout
The N-glycan precursor is flipped across the ER membrane, moving it from the cytosolic side to the ER lumenal side. The exact mechanism of this translocation is not well understood but protein RFT1 homolog (RFT1) is known to be involved (Helenius et al. 2002). Defects in RFT1 are associated with congenital disorder of glycosylation 1n (RFT1-CDG, CDG-1n). The disease is a multi-system disorder characterised by under-glycosylated serum glycoproteins. Early-onset developmental retardation, dysmorphic features, hypotonia, coagulation disorders and immunodeficiency are reported features of this disorder. In a patient with RFT1-CDG, Haeuptle et al. identified a homozygous C-T transition at nucleotide 199, resulting in a substitution of cysteine for arginine at codon 67 (R67C) (Haeuptle et al. 2008).
Literature References
PubMed ID Title Journal Year
18313027 Human RFT1 deficiency leads to a disorder of N-linked glycosylation

Hennet, T, Haeuptle, MA, Kastaniotis, AJ, Neupert, C, Pujol, FM, Winchester, B, Aebi, M

Am J Hum Genet 2008
11807558 Translocation of lipid-linked oligosaccharides across the ER membrane requires Rft1 protein

Walter, P, Valvano, MA, Helenius, J, Marolda, CL, Aebi, M, Ng, DT

Nature 2002
Catalyst Activity

glycolipid floppase activity of RFT1 R67C [endoplasmic reticulum membrane]

Normal reaction
Functional status

Loss of function of RFT1 R67C [endoplasmic reticulum membrane]

Cite Us!