Fachbereich Veterinärmedizin


Service-Navigation

    Publikationsdatenbank

    Intrinsic membrane association of the cytoplasmic tail of influenza virus M2 protein and lateral membrane sorting regulated by cholesterol binding and palmitoylation (2011)

    Art
    Zeitschriftenartikel / wissenschaftlicher Beitrag
    Autoren
    Thaa, Bastian (WE 5)
    Levental, Ilya
    Herrmann, Andreas
    Veit, Michael (WE 5)
    Quelle
    The Biochemical journal; 437(3) — S. 389–397
    ISSN: 0264-6021
    Sprache
    Englisch
    Verweise
    DOI: 10.1042/BJ20110706
    Pubmed: 21592088
    Kontakt
    Institut für Virologie

    Robert-von-Ostertag-Str. 7-13
    Gebäude 35
    14163 Berlin
    Tel. +49 30 838 51833 Fax. +49 30 838 451847
    email:viro@zedat.fu-berlin.de

    Abstract / Zusammenfassung

    The influenza virus transmembrane protein M2 is a proton channel, but also plays a role in the scission of nascent virus particles from the plasma membrane. An amphiphilic helix in the CT (cytoplasmic tail) of M2 is supposed to insert into the lipid bilayer, thereby inducing curvature. Palmitoylation of the helix and binding to cholesterol via putative CRAC (cholesterol recognition/interaction amino acid consensus) motifs are believed to target M2 to the edge of rafts, the viral-budding site. In the present study, we tested pre-conditions of this model, i.e. that the CT interacts with membranes, and that acylation and cholesterol binding affect targeting of M2. M2-CT, purified as a glutathione transferase fusion protein, associated with [3H]photocholesterol and with liposomes. Mutation of tyrosine residues in the CRAC motifs prevented [(3)H]photocholesterol labelling and reduced liposome binding. M2-CT fused to the yellow fluorescent protein localized to the Golgi in transfected cells; membrane targeting was dependent on CRAC and (to a lesser extent) on palmitoylation. Preparation of giant plasma membrane vesicles from cells expressing full-length M2-GFP (green fluorescent protein) showed that the protein is partly present in the raft domain. Raft targeting required palmitoylation, but not the CRAC motifs. Thus palmitoylation and cholesterol binding differentially affect the intrinsic membrane binding of the amphiphilic helix.