TY - JOUR
T1 - A Golgi UDP-GlcNAc transporter delivers substrates for N-linked glycans and sphingolipids
AU - Ebert, Berit
AU - Rautengarten, Carsten
AU - McFarlane, Heather E.
AU - Rupasinghe, Thusitha
AU - Zeng, Wei
AU - Ford, Kristina
AU - Scheller, Henrik V.
AU - Bacic, Antony
AU - Roessner, Ute
AU - Persson, Staffan
AU - Heazlewood, Joshua L.
N1 - Publisher Copyright:
© 2018, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2018/10/1
Y1 - 2018/10/1
N2 - Glycosylation requires activated glycosyl donors in the form of nucleotide sugars to drive processes such as post-translational protein modifications and glycolipid and polysaccharide biosynthesis. Most of these reactions occur in the Golgi, requiring cytosolic-derived nucleotide sugars, which need to be actively transferred into the Golgi lumen by nucleotide sugar transporters. We identified a Golgi-localized nucleotide sugar transporter from Arabidopsis thaliana with affinity for UDP-N-acetyl-d-glucosamine (UDP-GlcNAc) and assigned it UDP-GlcNAc transporter 1 (UGNT1). Profiles of N-glycopeptides revealed that plants carrying the ugnt1 loss-of-function allele are virtually devoid of complex and hybrid N-glycans. Instead, the N-glycopeptide population from these alleles exhibited high-mannose structures, representing structures prior to the addition of the first GlcNAc in the Golgi. Concomitantly, sphingolipid profiling revealed that the biosynthesis of GlcNAc-containing glycosyl inositol phosphorylceramides (GIPCs) is also reliant on this transporter. By contrast, plants carrying the loss-of-function alleles affecting ROCK1, which has been reported to transport UDP-GlcNAc and UDP-N-acetylgalactosamine, exhibit no changes in N-glycan or GIPC profiles. Our findings reveal that plants contain a single UDP-GlcNAc transporter that delivers an essential substrate for the maturation of N-glycans and the GIPC class of sphingolipids.
AB - Glycosylation requires activated glycosyl donors in the form of nucleotide sugars to drive processes such as post-translational protein modifications and glycolipid and polysaccharide biosynthesis. Most of these reactions occur in the Golgi, requiring cytosolic-derived nucleotide sugars, which need to be actively transferred into the Golgi lumen by nucleotide sugar transporters. We identified a Golgi-localized nucleotide sugar transporter from Arabidopsis thaliana with affinity for UDP-N-acetyl-d-glucosamine (UDP-GlcNAc) and assigned it UDP-GlcNAc transporter 1 (UGNT1). Profiles of N-glycopeptides revealed that plants carrying the ugnt1 loss-of-function allele are virtually devoid of complex and hybrid N-glycans. Instead, the N-glycopeptide population from these alleles exhibited high-mannose structures, representing structures prior to the addition of the first GlcNAc in the Golgi. Concomitantly, sphingolipid profiling revealed that the biosynthesis of GlcNAc-containing glycosyl inositol phosphorylceramides (GIPCs) is also reliant on this transporter. By contrast, plants carrying the loss-of-function alleles affecting ROCK1, which has been reported to transport UDP-GlcNAc and UDP-N-acetylgalactosamine, exhibit no changes in N-glycan or GIPC profiles. Our findings reveal that plants contain a single UDP-GlcNAc transporter that delivers an essential substrate for the maturation of N-glycans and the GIPC class of sphingolipids.
UR - http://www.scopus.com/inward/record.url?scp=85053684373&partnerID=8YFLogxK
U2 - 10.1038/s41477-018-0235-5
DO - 10.1038/s41477-018-0235-5
M3 - Article
SN - 2055-026X
VL - 4
SP - 792
EP - 801
JO - Nature Plants
JF - Nature Plants
IS - 10
ER -