title: Structures and biosynthesis of the N- and O-glycans of recombinant human oviduct-specific glycoprotein expressed in human embryonic kidney cells.
abstract: Oviduct-specific glycoprotein (OVGP1) is a major mucin-like glycoprotein synthesized and secreted exclusively by non-ciliated secretory cells of mammalian oviduct. In vitro functional studies showed that OVGP1 plays important roles during fertilization and early embryo development. We have recently produced recombinant human oviduct-specific glycoprotein (rhOVGP1) in human embryonic kidney 293 (HEK293) cells. The present study was undertaken to characterize the structures and determine the biosynthetic pathways of the N- and O-glycans of rhOVGP1. Treatment of the stable rhOVGP1-expressing HEK293 cells with either GalNAcα-Bn to block O-glycan extension, tunicamycin to block N-glycosylation, or neuraminidase increased the electrophoretic mobility of rhOVGP1. A detailed analysis of O- and N-linked glycans of rhOVGP1 by mass spectrometry showed a broad range of many simple and complex glycan structures. In order to identify the enzymes involved in the glycosylation of rhOVGP1, we assayed glycosyltransferase activities involved in the assembly of O- and N-glycans in HEK293 cells, and compared these to those from the immortalized human oviductal cells (OE-E6/E7). Our results demonstrate that HEK293 and OE-E6/E7 cells exhibit a similar spectrum of glycosyltransferase activities that can synthesize elongated and sialylated O-glycans with core 1 and 2 structures, as well as complex multiantennary N-glycans. It is anticipated that the knowledge gained from the present study will facilitate future studies of the role of the glycans of human OVGP1 in fertilization and early embryo development.
authors: Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada.
authors: Xiaojing
authors: X
authors: Yang
authors: Shujuan
authors: S
authors: Tao
authors: Ron
authors: R
authors: Orlando
authors: Inka
authors: I
authors: Brockhausen
authors: Frederick W K
authors: FW
authors: Kan
mesh_terms: D002460:Cell Line; D006023:Glycoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D015394:Molecular Structure; D011134:Polysaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; C091468:OVGP1 protein, human; D011134:Polysaccharides; D011994:Recombinant Proteins