Mannose receptor polyubiquitination regulates endosomal recruitment of p97 and cytosolic antigen translocation for cross-presentation

Proc Natl Acad Sci U S A. 2011 Jun 14;108(24):9933-8. doi: 10.1073/pnas.1102397108. Epub 2011 May 31.

Abstract

The molecular mechanisms regulating noncanonical protein transport across cellular membranes are poorly understood. Cross-presentation of exogenous antigens on MHC I molecules by dendritic cells (DCs) generally requires antigen translocation from the endosomal compartment into the cytosol for proteasomal degradation. In this study, we demonstrate that such translocation is controlled by the endocytic receptor and regulated by ubiquitination. Antigens internalized by the mannose receptor (MR), an endocytic receptor that targets its ligands specifically toward cross-presentation, were translocated into the cytosol only after attachment of a lysin48-linked polyubiquitin chain to the cytosolic region of the MR. Furthermore, we identify TSG101 as a central regulator of MR ubiquitination and antigen translocation. Importantly, we demonstrate that MR polyubiquitination mediates the recruitment of p97, a member of the ER-associated degradation machinery that provides the driving force for antigen translocation, toward the endosomal membrane, proving the central role of the endocytic receptor and its ubiquitination in antigen translocation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / immunology
  • Adenosine Triphosphatases / metabolism*
  • Animals
  • Antigens / immunology
  • Antigens / metabolism*
  • Blotting, Western
  • Bone Marrow Cells / immunology
  • Bone Marrow Cells / metabolism
  • Cross-Priming*
  • Cytosol / immunology
  • Cytosol / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / immunology
  • DNA-Binding Proteins / metabolism
  • Dendritic Cells / immunology
  • Dendritic Cells / metabolism
  • Endocytosis / immunology
  • Endosomal Sorting Complexes Required for Transport / genetics
  • Endosomal Sorting Complexes Required for Transport / immunology
  • Endosomal Sorting Complexes Required for Transport / metabolism
  • Endosomes / immunology
  • Endosomes / metabolism
  • Flow Cytometry
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Lectins, C-Type / genetics
  • Lectins, C-Type / immunology
  • Lectins, C-Type / metabolism*
  • Mannose-Binding Lectins / genetics
  • Mannose-Binding Lectins / immunology
  • Mannose-Binding Lectins / metabolism*
  • Mice
  • Mice, Knockout
  • Microscopy, Fluorescence
  • Nuclear Proteins / genetics
  • Nuclear Proteins / immunology
  • Nuclear Proteins / metabolism*
  • Ovalbumin / immunology
  • Ovalbumin / metabolism
  • Polyubiquitin / metabolism
  • Protein Transport / immunology
  • RNA Interference
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / immunology
  • Receptors, Cell Surface / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / immunology
  • Transcription Factors / metabolism
  • Ubiquitination / immunology

Substances

  • Antigens
  • DNA-Binding Proteins
  • Endosomal Sorting Complexes Required for Transport
  • Lectins, C-Type
  • Mannose-Binding Lectins
  • Nuclear Proteins
  • Receptors, Cell Surface
  • Transcription Factors
  • Tsg101 protein
  • mannose receptor
  • Polyubiquitin
  • Green Fluorescent Proteins
  • Ovalbumin
  • Adenosine Triphosphatases
  • p97 ATPase