Different ways to reach the top of a cell. Analysis of rotavirus assembly and targeting in human intestinal cells reveals an original raft-dependent, Golgi-independent apical targeting pathway

Autor: Germain Trugnan, Agnès Gardet, Catherine Sapin, Michelyne Breton, Olivier Delmas, Serge Chwetzoff, Odile Colard, Jean Cohen
Přispěvatelé: Laboratoire Bordelais de Recherche en Informatique (LaBRI), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB), Université Pierre et Marie Curie - Paris 6 (UPMC), Trafic Membranaire et Signalisation Dans les Cellules Epitheliales, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de génétique moléculaire (CGM), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux (UB)-École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2004
Předmět:
Zdroj: Virology
Virology, Elsevier, 2004, 327 ((2)), pp.157-61. ⟨10.1016/j.virol.2004.06.029⟩
Virology, 2004, 327 ((2)), pp.157-61. ⟨10.1016/j.virol.2004.06.029⟩
ISSN: 0042-6822
1096-0341
Popis: IntroductionSince the pioneering works of David Sabatini’s group,viruses have demonstrated their high usefulness to unravelproperties of eukaryotic cells. This holds especially true forstudies on polarized protein targeting in epithelial cells inwhich influenza and vesicular stomatitis virus proteins havebeen widely used to characterize the mechanisms of proteinsorting (Rodriguez-Boulan and Sabatini, 1978). Since then,the study of polarized targeting mechanisms in epithelialcellshasremainedahighlyactivefieldofresearch.Althoughseveral signals and pathways have been described, there isuntil now no clear consensus on how molecules are sortedand transported from the Golgi apparatus to the cell surface.Simons and Ikonen (1997) suggested that specializedmembrane microdomains termed braftsQ, which are enrichedincholesteroland(glyco)sphingolipidsandformedbylateralsegregation of membrane lipids, may play a crucial role insorting mechanisms of subsets of proteins that will betargeted to the apical membrane. This braft hypothesisQ fitswith numerous observations indicating that apically targetedmolecules associate with lipid rafts in the Golgi apparatusbefore being incorporated into specific post-Golgi carriers(Simons and Ikonen, 1997). However, it has also beenobserved that raft association is not sufficient to confer astrict apical targeting, because several raft-associated pro-teins are targeted to the basolateral membrane in various celltypes (Kreitzer et al., 2003; Lipardi et al. 2000). In a recentreview,ithasalsobeensuggestedthatformationofpolymersor aggregates that are favored by the presence of membranemicrodomains may help the sorting process between apicaland basolateral proteins (Helms and Zurzolo, 2004).A few years ago, we started to study the morphogenesisand targeting of another virus, namely rotavirus, whichappeared to behave very differently as compared topreviously studied virus. As outlined below, this virus andits main structural proteins do not seem to follow a classicalexocytic route, although the virus was specifically deliveredto the apical pole of intestinal cells (Jourdan et al., 1997).We realized that most of the proteins of this virus werecytosolic proteins that have no specific signal to enter theexocytic pathway. These proteins are synthesized on freeribosomes and directly released within the cytosol. Little isknown on the mechanisms that control their sorting andtargeting. In a recent review, Walter Nickel summarized thedata obtained on what was called bthe nonclassical proteinsecretionQ, a pathway that by-passes ER and Golgi compart-ments (Nickel, 2003). Four mechanisms have been sug-gested for this atypical plasma membrane targeting: (1) a re-entry in the endosomal compartment (used for example byIL1h); (2) the use of specific transporters at the cell surface(used by FGF1 and FGF2); (3) a translocation at the
Databáze: OpenAIRE
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