title: Cell surface expression of immature H glycoprotein in measles virus-infected cells.
abstract: Two forms of hemagglutinin (H) protein, one with an apparent molecular mass of 78 kDa (78K H protein) and the other with that of 74 kDa (74K H protein), are present in cells infected with measles virus (MV). We previously observed that only the mature 78K H protein, a completely glycosylated form of the 74K H protein, was expressed on the cell surface of the infected cells. In the present study, we detected transient expression of the 74K H protein on the cell surface of infected cells by pulse-chase studies, although the level of this expression was much lower than that of the 78K H protein. On the cell surface the 74K H protein was present as dimers and sensitive to endo-beta-N-acetylglucosaminidase H digestion. Treatment with brefeldin A, which blocks the transport of membrane and secretory proteins from the endoplasmic reticulum to the Golgi apparatus, inhibited the cell surface expression of the 78K H protein, but not that of the 74K H protein. These data suggest that a part of the MV 74K H proteins could be transported directly to the cell surface - probably via an alternative pathway - without processing to the complex form in the Golgi apparatus.
authors.affiliation: Department of Virology, Osaka City University Medical School, Asahimachi 1-4-3, Abeno-ku, Osaka, Japan. ogurah@med.osaka-cu.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Ogura
authors.forename: I
authors.initials: I
authors.lastname: Matsunaga
authors.forename: Y
authors.initials: Y
authors.lastname: Takano
authors.forename: X
authors.initials: X
authors.lastname: Ning
authors.forename: M
authors.initials: M
authors.lastname: Ayata
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Seto
authors.forename: K
authors.initials: K
authors.lastname: Furukawa
authors.forename: N
authors.initials: N
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Shingai
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Ichihara
authors.forename: H
authors.initials: H
authors.lastname: Kubo
authors.forename: T
authors.initials: T
authors.lastname: Murakami
mesh_terms: D000818:Animals; D020126:Brefeldin A / Q000494:pharmacology; D019556:COS Cells; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002522:Chlorocebus aethiops; D006388:Hemagglutinins / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D008459:Measles virus / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D014709:Vero Cells
chemical_list: D006388:Hemagglutinins; D020033:Protein Isoforms; D011500:Protein Synthesis Inhibitors; D020126:Brefeldin A