Molecular basis of N-acetylglucosaminyltransferase I deficiency in Arabidopsis thaliana plants lacking complex N-glycans

5 April 2005

journal article
Published by Portland Press Ltd. in Biochemical Journal

Vol. 387 (2) , 385-391
https://doi.org/10.1042/bj20041686

Abstract

GnTI (N-acetylglucosaminyltransferase I) is a Golgi-resident enzyme essential for the processing of high-mannose to hybrid and complex N-glycans. The Arabidopsis thaliana cgl mutant lacks GnTI activity and as a consequence accumulates oligomannosidic structures. Molecular cloning of cgl GnTI cDNA revealed a point mutation, which causes a critical amino acid substitution (Asp¹⁴⁴→Asn), thereby creating an additional N-glycosylation site. Heterologous expression of cgl GnTI in insect cells confirmed its lack of activity and the use of the N-glycosylation site. Remarkably, introduction of the Asp¹⁴⁴→Asn mutation into rabbit GnTI, which does not result in the formation of a new N-glycosylation site, led to a protein with strongly reduced, but still detectable enzymic activity. Expression of Asn¹⁴⁴ rabbit GnTI in cgl plants could partially restore complex N-glycan formation. These results indicate that the complete deficiency of GnTI activity in cgl plants is mainly due to the additional N-glycan, which appears to interfere with the proper folding of the enzyme.

Keywords

This publication has 37 references indexed in Scilit:

Caenorhabditis elegans triple null mutant lacking UDP-N-acetyl-D-glucosamine:α-3-D-mannoside β1,2-N-acetylglucosaminyltransferase I
Biochemical Journal, 2004
Toxin‐dependent utilization of engineered ribosomal protein L3 limits trichothecene resistance in transgenic plants
Plant Biotechnology Journal, 2004
Generation of Arabidopsis thaliana plants with complex N‐glycans lacking β1,2‐linked xylose and core α1,3‐linked fucose
FEBS Letters, 2004
Catalytic mechanism of the inverting N-acetylglucosaminyltransferase I: DFT quantum mechanical model of the reaction pathway and determination of the transition state structure
Glycobiology, 2003
Growth Stage-Based Phenotypic Analysis of Arabidopsis: A Model for High Throughput Functional Genomics in Plants
Plant Cell, 2001
Isolation and Characterization of Plant N-Acetyl Glucosaminyltransferase I (GntI) cDNA Sequences. Functional Analyses in the Arabidopsis cgl Mutant and in Antisense Plants
Plant Physiology, 2000
An Arabidopsis thaliana cDNA Complements the N-Acetylglucosaminyltransferase I Deficiency of CHO Lec1 Cells
Biochemical and Biophysical Research Communications, 1999
Processing of asparagine-linked oligosaccharides in insect cells. N-Acetylglucosaminyltransferase I and II activities in cultured lepidopteran cells
Glycobiology, 1993
Isolation of a Mutant Arabidopsis Plant That Lacks N-Acetyl Glucosaminyl Transferase I and Is Unable to Synthesize Golgi-Modified Complex N-Linked Glycans
Plant Physiology, 1993
A Revised Medium for Rapid Growth and Bio Assays with Tobacco Tissue Cultures
Physiologia Plantarum, 1962