title: The amino acid at the X position of an Asn-X-Ser sequon is an important determinant of N-linked core-glycosylation efficiency.
abstract: N-Linked glycosylation is a common form of protein processing that can profoundly affect protein expression, structure, and function. N-Linked glycosylation generally occurs at the sequon Asn-X-Ser/Thr, where X is any amino acid except Pro. To assess the impact of the X amino acid on core glycosylation, rabies virus glycoprotein variants were generated by site-directed mutagenesis with each of the 20 common amino acids substituted at the X position of an Asn-X-Ser sequon. The efficiency of core glycosylation at the sequon in each variant was quantified in a rabbit reticulocyte lysate cell-free translation system supplemented with canine pancreas microsomes. The presence of Pro at the X position completely blocked core glycosylation, whereas Trp, Asp, Chi, and Leu were associated with inefficient core glycosylation. The other variants were more efficiently glycosylated, and several were fully glycosylated. These findings demonstrate that the X amino acid is an important determinant of N-linked core-glycosylation efficiency.
authors.affiliation: Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Shakin-Eshleman
authors.forename: S L
authors.initials: SL
authors.lastname: Spitalnik
authors.forename: L
authors.initials: L
authors.lastname: Kasturi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006031:Glycosylation; D066298:In Vitro Techniques; D008954:Models, Biological; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010957:Plasmids / Q000235:genetics; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D011820:Rabies virus / Q000235:genetics / Q000378:metabolism; D012156:Reticulocytes / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D000956:Antigens, Viral; D017931:DNA Primers; D006023:Glycoproteins; D011506:Proteins; D014759:Viral Envelope Proteins; C064951:glycoprotein G, Rabies virus