Glycosylation efficiency of Asn-Xaa-Thr sequons depends both on the distance from the C terminus and on the presence of a downstream transmembrane segment
2000 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 275, no 23, 17338-17343 p.Article in journal (Refereed) Published
Statistical studies of N-glycosylated proteins have indicated that the frequency of nonglycosylated Asn-Xaa-(Thr/Ser) sequons increases toward the C terminus (Gavel, Y., and von Heijne, G. (1990) Protein Eng. 3, 433-442), Using in vitro transcription/translation of a truncated model protein in the presence of dog pancreas microsomes, we find that glycosylation efficiency of Asn-Xaa-Thr sequons indeed is reduced when the sequon is within similar to 60 residues of the C terminus. Surprisingly, the presence of a hydrophobic stop transfer sequence between the Asn-Xaa-Thr sequon and the C terminus results in a very different dependence of glycosylation efficiency on the distance to the C terminus, where the presence of the stop transfer segment inside the ribosome appears to cause a drastic drop in the level of glycosylation. We speculate that this may reflect a change in the structure of the ribosome/translocon complex induced by the stop transfer segment.
Place, publisher, year, edition, pages
2000. Vol. 275, no 23, 17338-17343 p.
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:su:diva-21427DOI: 10.1074/jbc.M002317200ISI: 000087485000019PubMedID: 10748070OAI: oai:DiVA.org:su-21427DiVA: diva2:187954