title: Synthesis and processing of the influenza virus neuraminidase, a type II transmembrane glycoprotein.
abstract: The influenza virus neuraminidase (NA), a type II transmembrane glycoprotein, is expressed at the surface of infected cells and is a major structural component of the virion. The kinetics of biosynthesis of NA, including modification of N-linked sugar chains, association with GRP78-BiP, oligomerization, and transport to the cell surface, were examined in A/WSN/33 influenza-infected BHK cells. Prior to gaining endoglycosidase H (endo H) resistance, NA was found to transiently associate with GRP78-BiP (t1/2 approximately 5 min). The protein was synthesized as a monomer and within 10 min a significant fraction of it was chased into dimers and tetramers with a t1/2 approximately 15 to 20 min before endo H resistance was acquired suggesting that oligomerization took place in the endoplasmic reticulum. WSN NA remained completely endo H sensitive up to 15 min after synthesis, acquired partial resistance to endo H between 15 and 30 min (t1/2 approximately 25 min) after synthesis and exhibited heterogeneity in endo H-resistant forms. NA was first detected at the cell surface 30 min after synthesis, increased to a maximum at 1 hr, after which it decreased, presumably due to incorporation into virions. The results on the biosynthesis of NA, a type II protein for which the three-dimensional structure is known, will be useful in structure/function and virion assembly studies.
authors.affiliation: Department of Microbiology and Immunology, Jonsson Comprehensive Cancer Center, University of California, Los Angeles School of Medicine 90024-1747.
authors.forename: B G
authors.initials: BG
authors.lastname: Hogue
authors.forename: D P
authors.initials: DP
authors.lastname: Nayak
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D006224:Cricetinae; D000091342:Endoplasmic Reticulum Chaperone BiP; D006031:Glycosylation; D006360:Heat-Shock Proteins; D006596:Hexosaminidases / Q000494:pharmacology; D066298:In Vitro Techniques; D009980:Influenza A virus / Q000378:metabolism*; D046911:Macromolecular Substances; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D008562:Membrane Glycoproteins / Q000378:metabolism*; D018832:Molecular Chaperones; D009439:Neuraminidase / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D013997:Time Factors; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D018832:Molecular Chaperones; D014764:Viral Proteins; D006596:Hexosaminidases; D009439:Neuraminidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase