title: Measles virus matrix protein specifies apical virus release and glycoprotein sorting in epithelial cells.
abstract: In polarized epithelial cells measles virus (MV) is predominantly released at the apical cell surface, irrespective of the sorting of its two envelope glycoproteins F and H. It has been reported previously that the viral matrix (M) protein modulates the fusogenic capacity of the viral envelope glycoproteins. Here, extant MV mutants and chimeras were used to determine the role of M protein in the transport of viral glycoproteins and release of progeny virions in polarized epithelial CaCo2 cells. In the absence of M, envelope glycoproteins are sorted to the basolateral surface, suggesting that they possess intrinsic basolateral sorting signals. However, interactions of M with the glycoprotein cytoplasmic tails allow M-glycoprotein co-segregation to the apical surface, suggesting a vectorial function of M to retarget the glycoproteins for apical virion release. Whereas this may allow virus airway shedding, the intrinsic sorting of the glycoproteins to the basolateral surface may account for systemic host infection by allowing efficient cell-cell fusion.
authors.affiliation: University of Zürich, Institute of Molecular Biology, Winterthurerstrasse 190, 8057 Zürich. naim@molbio.unizh.ch
authors.forename: H Y
authors.initials: HY
authors.lastname: Naim
authors.forename: E
authors.initials: E
authors.lastname: Ehler
authors.forename: M A
authors.initials: MA
authors.lastname: Billeter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018938:Caco-2 Cells; D002460:Cell Line; D016764:Cell Polarity; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism / Q000821:virology*; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008459:Measles virus / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008561:Membrane Fusion; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D014760:Viral Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014763:Viral Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D006023:Glycoproteins; D011993:Recombinant Fusion Proteins; D014760:Viral Fusion Proteins; D014763:Viral Matrix Proteins