Reactome | Flipping of the N-glycan precursor to inside the ER

Flipping of the N-glycan precursor to inside the ER

Stable Identifier

R-HSA-446212

Type

Reaction [transition]

Species

Homo sapiens

Compartment

endoplasmic reticulum membrane

ReviewStatus

5/5

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Flipping of the N-glycan precursor to inside the ER

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The precursor of the N-glycan sugar, now in the form of (GlcNAc)2 (Man)5 (PP-Dol), is flipped across the ER membrane, moving it from the cytosolic side into the ER lumen. The exact mechanism of this translocation is not well understood: the protein RFT1 is known to be involved (Helenius et al. 2002), along with an unknown flippase, which is distinct from the one that flips the Dol-P linked precursors (Dol-P-Mannose and Dol-P-glucose) (Sanyal et al. 2008). Defects in RFT1 are associated with Congenital Disorder of Glycosylation 1N (CDG1N) (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
18597486	Distinct flippases translocate glycerophospholipids and oligosaccharide diphosphate dolichols across the endoplasmic reticulum Sanyal, S, Menon, AK, Frank, CG	Biochemistry	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