title: N-linked glycosylation of AtVSR1 is important for vacuolar protein sorting in Arabidopsis.
abstract: Vacuolar sorting receptors (VSRs) in Arabidopsis mediate the sorting of soluble proteins to vacuoles in the secretory pathway. The VSRs are post-translationally modified by the attachment of N-glycans, but the functional significance of such a modification remains unknown. Here we have studied the role(s) of glycosylation in the stability, trafficking and vacuolar protein transport of AtVSR1 in Arabidopsis protoplasts. AtVSR1 harbors three complex-type N-glycans, which are located in the N-terminal 'PA domain', the central region and the C-terminal epidermal growth factor repeat domain, respectively. We have demonstrated that: (i) the N-glycans do not affect the targeting of AtVSR1 to pre-vacuolar compartments (PVCs) and its vacuolar degradation; and (ii) N-glycosylation alters the binding affinity of AtVSR1 to cargo proteins and affects the transport of cargo into the vacuole. Hence, N-glycosylation of AtVSR1 plays a critical role in its function as a VSR in plants.
authors.affiliation: School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Jinbo
authors.initials: J
authors.lastname: Shen
authors.forename: Yu
authors.initials: Y
authors.lastname: Ding
authors.forename: Caiji
authors.initials: C
authors.lastname: Gao
authors.forename: Enrique
authors.initials: E
authors.lastname: Rojo
authors.forename: Liwen
authors.initials: L
authors.lastname: Jiang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D017930:Genes, Reporter; D006031:Glycosylation; D030821:Plants, Genetically Modified; D021381:Protein Transport; D011523:Protoplasts; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C106564:ELP protein, Arabidopsis
keywords: Arabidopsis; N-glycosylation; cargo; vacuolar protein; vacuolar sorting receptor