Identification and characterization of a sixth structural protein of Lelystad virus: the glycoprotein GP2 encoded by ORF2 is incorporated in virus particles.
Previously we have shown that Lelystad virus (LV) contains five structural proteins, a nucleocapsid protein N, an integral membrane protein M, and three glycoproteins GP3, GP4, and GP5. In this study we identified a sixth structural protein of Lelystad virus. The protein has an apparent molecular weight of 29 to 30 kDa, was recognized by an ORF2-specific antipeptide serum in Western immunoblotting using sucrose gradient purified LV virions, and was shown to be N-glycosylated. It was therefore designated GP2. The GP2 protein was also immunoprecipitated by ORF2-specific antipeptide serum from lysates and extracellular virus of CL2621 cells infected with LV. A fraction of the GP2 protein present in these lysates contained an intrachain disulfide bond. Endoglycosidase H treatment of immunoprecipitates indicated that the endoglycosidase H-sensitive N-glycans of the GP2 protein become endoglycosidase H-resistant during passage through the Golgi compartment in cells infected with LV. In contrast, the N-glycans of the GP2 protein expressed individually in a recombinant Semliki Forest virus remained endoglycosidase H-sensitive, indicating that the GP2 protein was retained in the endoplasmic reticulum. LV is the first arterivirus which has been demonstrated to contain six virion-associated proteins, one nucleocapsid protein, one integral membrane protein, and four glycoproteins.
Meulenberg
J J
JJ
Institute for Animal Science and Health, Lelystad, The Netherlands. J.J.M.Meulenberg@id.dlo.nl
Petersen-den Besten
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D000477:Alkylating Agents / Q000494:pharmacology; D000581:Amidohydrolases; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D019281:Dimerization; D004220:Disulfides; D005033:Ethylmaleimide / Q000494:pharmacology; D006023:Glycoproteins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics; D006031:Glycosylation; D006596:Hexosaminidases; D007460:Iodoacetamide / Q000494:pharmacology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames / Q000235:genetics*; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D019316:Porcine respiratory and reproductive syndrome virus / Q000737:chemistry* / Q000235:genetics; D011233:Precipitin Tests; D015678:Viral Structural Proteins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics; D014771:Virion / Q000737:chemistry
D000477:Alkylating Agents; D004220:Disulfides; D006023:Glycoproteins; D015678:Viral Structural Proteins; D006596:Hexosaminidases; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D005033:Ethylmaleimide; D007460:Iodoacetamide