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The yeast WBP1 is essential for oligosaccharyl transferase activity in vivo and in vitro.
Author(s) -
Heesen S.,
Janetzky B.,
Lehle L.,
Aebi M.
Publication year - 1992
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1992.tb05265.x
Subject(s) - biology , in vivo , in vitro , yeast , transferase , biochemistry , microbiology and biotechnology , genetics , enzyme
Asparagine‐linked N‐glycosylation is a highly conserved and functionally important modification of proteins in eukaryotic cells. The central step in this process is a cotranslational transfer of lipid‐linked core oligosaccharides to selected Asn‐X‐Ser/Thr‐sequences of nascent polypeptide chains, catalysed by the enzyme N‐oligosaccharyl transferase. In this report we show that the essential yeast protein WBP1 (te Heesen et al., 1991) is required for N‐oligosaccharyl transferase in vivo and in vitro. Depletion of WBP1 correlates with a defect in transferring core oligosaccharides to carboxypeptidase Y and proteinase A in vivo. In addition, in vitro N‐glycosylation of the acceptor peptide Tyr‐Asn‐Leu‐Thr‐Ser‐Val using microsomal membranes from WBP1 depleted cells is reduced as compared with membranes from wild‐type cells. We propose that WBP1 is an essential component of the oligosaccharyl transferase in yeast.