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  • The EMBO Journal (2000) 19, 870 - 881
  • doi:10.1093/emboj/19.5.870

The luminal part of the murine cytomegalovirus glycoprotein gp40 catalyzes the retention of MHC class I molecules

Heike Ziegler1, Walter Muranyi1, Hans-Gerhard Burgert1, Elisabeth Kremmer2 and Ulrich H. Koszinowski

  1. Max-von-Pettenkofer Institut, Genzentrum, Ludwig-Maximilians-Universität München, D-81377 München, Germany
  2. GSF-Forschungszentrum für Umwelt und Gesundheit, Institut für Molekulare Immunologie, D-81377 München, Germany

Correspondence to:

Ulrich H. Koszinowski, Max-von-Pettenkofer Institut, Lehrstuhl Virologie, Pettenkofer Strasse 9a, D-80336 München, Germany, E-mail: koszinowski@m3401.mpk.med.uni-muenchen.de

Received 17 August 1999; Accepted 10 January 2000; Revised 16 September 1999

Murine cytomegalovirus (MCMV) interferes with the MHC class I pathway of antigen presentation. The type I transmembrane glycoprotein gp40, encoded by the gene m152, retains major histocompatibility complex (MHC) class I complexes in the endoplasmic reticulum (ER)–Golgi intermediate compartment (ERGIC)/cis-Golgi. These MHC class I complexes are stable, show an extended half-life and do not exchange beta2-microglobulin, whereas gp40 reaches an endosomal/lysosomal compartment where it subsequently is degraded. The analysis of regions within the viral protein that are essential for MHC class I retention revealed that a secreted form of gp40, lacking the cytoplasmic tail and the transmembrane region, still has the capacity to retain MHC class I complexes. Continuous expression of gp40 is not required for MHC class I retention. Our data indicate that the retention of MHC class I complexes in the ERGIC/cis-Golgi is triggered by gp40 and does not require the further presence of the viral protein.

  • Keywords:

    • antigen presentation,
    • ERGIC,
    • cis-Golgi retention,
    • immune evasion,
    • MHC class I pathway,
    • murine cytomegalovirus