Glycosylation of Nuclear Pore Protein ~62
نویسنده
چکیده
The addition of O-linked N-acetylglucosamine (GlcNAc) to the major nuclear pore complex glycoprotein p62 was examined. Expression of the rat p62 cDNA in transfected monkey cells was detected using a rat p62-specific antipeptide antiserum and two previously described nuclear pore-specific monoclonal antibodies which require O-linked GlcNAc for binding. Although the p62 cDNA was predicted to encode a 54kDa polypeptide, the product expressed in monkey cells migrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis as two species of 62 and 59kDa. Cell-free translation of the p62 z% uitro transcript yielded a 59-kDa polypeptide using wheat germ extract and a 62-kDa product using a commercially available rabbit reticulocyte lysate. Several lines of evidence indicated that the 62-kDa rabbit reticulocyte lysate translation product was modified by O-linked N-acetylglucosamine; the protein bound specifically to a wheat germ agglutinin affinity column and was converted to 59 kDa when treated with jack bean @-acetylglucosaminidase. The 59-kDa unglycosylated wheat germ translation product was converted to the 62-kDa glycosylated form upon incubation with reticulocyte lysate demonstrating that O-linked GlcNAc can be added to p62 post-translationally.
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