β-Arrestin-1 mediates the TCR-triggered re-routing of distal receptors to the immunological synapse by a PKC-mediated mechanism

EMBO J. 2014 Mar 18;33(6):559-77. doi: 10.1002/embj.201386022. Epub 2014 Feb 6.

Abstract

T-cell receptors (TCR) recognize their antigen ligand at the interface between T cells and antigen-presenting cells, known as the immunological synapse (IS). The IS provides a means of sustaining the TCR signal which requires the continual supply of new TCRs. These are endocytosed and redirected from distal membrane locations to the IS. In our search for novel cytoplasmic effectors, we have identified β-arrestin-1 as a ligand of non-phosphorylated resting TCRs. Using dominant-negative and knockdown approaches we demonstrate that β-arrestin-1 is required for the internalization and downregulation of non-engaged bystander TCRs. Furthermore, TCR triggering provokes the β-arrestin-1-mediated downregulation of the G-protein coupled chemokine receptor CXCR4, but not of other control receptors. We demonstrate that β-arrestin-1 recruitment to the TCR, and bystander TCR and CXCR4 downregulation, are mechanistically mediated by the TCR-triggered PKC-mediated phosphorylation of β-arrestin-1 at Ser163. This mechanism allows the first triggered TCRs to deliver a stop migration signal, and to promote the internalization of distal TCRs and CXCR4 and their translocation to the IS. This receptor crosstalk mechanism is critical to sustain the TCR signal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arrestins / metabolism*
  • Blotting, Western
  • Electroporation
  • Fluorescent Antibody Technique
  • Gene Expression Regulation / immunology*
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Humans
  • Immunological Synapses / metabolism*
  • Immunoprecipitation
  • Jurkat Cells
  • Mice
  • Mice, Transgenic
  • Microscopy, Fluorescence
  • Models, Immunological*
  • Pyrimidines
  • Receptors, Antigen, T-Cell / metabolism*
  • Receptors, CXCR4 / metabolism
  • Signal Transduction / immunology*
  • Time-Lapse Imaging
  • beta-Arrestin 1
  • beta-Arrestins

Substances

  • AG 1879
  • ARRB1 protein, human
  • Arrb1 protein, mouse
  • Arrestins
  • Pyrimidines
  • Receptors, Antigen, T-Cell
  • Receptors, CXCR4
  • beta-Arrestin 1
  • beta-Arrestins