N-glycan trimming by glucosidase II is essential for Arabidopsis development

SOUSSILANE P; D'ALESSIO C; PACCALET T; FITCHETTE AC; PARODI AJ; WILLIAMSON R; PLASSON C; FAYE L; GOMORD V

GLYCOCONJUGATE JOURNAL

Springer

Lugar: United States ; Año: 2009 vol. 26 p. 597 - 607

0282-0080

Glucosidase II, one of the early N-glycan processing enzymes and a major player in the glycoprotein folding quality control, has been described as a soluble heterodimer composed of alpha and beta subunits. Here we present the first characterization of a plant glucosidase II alpha subunit at the molecular level. Expression of the Arabidopsis alpha subunit restored N-glycan maturation capacity in Schizosaccharomyces pombe alpha minus or alpha and beta minus deficient mutants, but with a lower efficiency in the last case. Inactivation of the alpha subunit in a temperature sensitive Arabidopsis mutant blocked N-glycan processing after a first  trimming by glucosidase I and strongly affected seedling  development.