Inhibition of asparagine-linked glycosylation by incorporation of a threonine analog into nascent peptide chains.
The importance of threonine in the Asn-X-Thr recognition sequence for asparagine-linked glycosylation was tested by examining the effect of a threonine analog, beta-hydroxynorvaline, on co-translational glycosylation in Krebs' II ascites tumor lysates. beta-Hydroxynorvaline inhibited the glycosylation of the alpha subunit of human chorionic gonadotropin and the beta subunit of bovine luteinizing hormone; both proteins contain Asn-X-Thr recognition sites. The effect was prevented by threonine, indicating that beta-hydroxynorvaline acted via its incorporation into protein. These results provide direct evidence for the role of threonine in Asn-X-Thr sites for asparagine-linked glycosylation. The results support the view that this site is sensitive to steric hindrance.
D000818:Animals; D001216:Asparagine / Q000378:metabolism*; D002287:Carcinoma, Krebs 2 / Q000378:metabolism*; D002417:Cattle; D006063:Chorionic Gonadotropin / Q000096:biosynthesis; D006027:Glycosides / Q000378:metabolism*; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D007986:Luteinizing Hormone / Q000096:biosynthesis; D051379:Mice; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D010452:Peptide Biosynthesis; D014176:Protein Biosynthesis / Q000187:drug effects*; D012333:RNA, Messenger / Q000378:metabolism; D013912:Threonine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D014415:Tunicamycin / Q000494:pharmacology
D006063:Chorionic Gonadotropin; D006027:Glycosides; D012333:RNA, Messenger; D014415:Tunicamycin; C010994:3-hydroxynorvaline; D013912:Threonine; D001216:Asparagine; D007986:Luteinizing Hormone