Na+/H+ exchanger regulatory factor-1 is involved in chemokine receptor homodimer CCR5 internalization and signal transduction but does not affect CXCR4 homodimer or CXCR4-CCR5 heterodimer

J Biol Chem. 2010 Nov 5;285(45):34653-64. doi: 10.1074/jbc.M110.106591. Epub 2010 Aug 26.

Abstract

Chemokine receptors are members of the G protein-coupled receptor (GPCR) family. CCR5 is also the principal co-receptor for macrophage-tropic strains of human immunodeficiency virus, type 1 (HIV-1), and efforts have been made to develop ligands to inhibit HIV-1 infection by promoting CCR5 receptor endocytosis. Given the nature of GPCRs and their propensity to form oligomers, one can consider ligand-based therapies as unselective in terms of the oligomeric composition of complexes. For example, a ligand targeting a CCR5 homomer could likely induce signal transduction on a heteromeric CCR5-CXCR4. Other avenues could therefore be explored. We identified a receptor adaptor interacting specifically with one receptor complex but not others. NHERF1, an adaptor known for its role in desensitization, internalization, and regulation of the ERK signaling cascade for several GPCRs, interacts via its PDZ2 domain with the CCR5 homodimer but not with the CXCR4-CCR5 heterodimer or CXCR4 homodimer. To further characterize this interaction, we also show that NHERF1 increases the CCR5 recruitment of arrestin2 following stimulation. NHERF1 is also involved in CCR5 internalization, as we demonstrate that co-expression of constructs bearing the PDZ2 domain can block CCR5 internalization. We also show that NHERF1 potentiates RANTES (regulated on activation normal T cell expressed and secreted)-induced ERK1/2 phosphorylation via CCR5 activation and that this activation requires NHERF1 but not arrestin2. Taken together, our results suggest that oligomeric receptor complexes can associate specifically with partners and that in this case NHERF1 could represent an interesting new target for the regulation of CCR5 internalization and potentially HIV infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Chemokine CCL5 / genetics
  • Chemokine CCL5 / metabolism
  • HIV Infections / genetics
  • HIV Infections / metabolism*
  • HIV-1 / genetics
  • HIV-1 / metabolism*
  • Humans
  • MAP Kinase Signaling System*
  • Mitogen-Activated Protein Kinase 1 / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / genetics
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Phosphorylation / genetics
  • Protein Multimerization*
  • Protein Structure, Quaternary
  • Protein Structure, Tertiary
  • Receptors, CCR5 / genetics
  • Receptors, CCR5 / metabolism*
  • Receptors, CXCR4 / genetics
  • Receptors, CXCR4 / metabolism*
  • Sodium-Hydrogen Exchangers / genetics
  • Sodium-Hydrogen Exchangers / metabolism*

Substances

  • CCL5 protein, human
  • CXCR4 protein, human
  • Chemokine CCL5
  • Phosphoproteins
  • Receptors, CCR5
  • Receptors, CXCR4
  • Sodium-Hydrogen Exchangers
  • sodium-hydrogen exchanger regulatory factor
  • MAPK1 protein, human
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3