Filamin a binds to CCR2B and regulates its internalization

PLoS One. 2010 Aug 17;5(8):e12212. doi: 10.1371/journal.pone.0012212.

Abstract

The chemokine (C-C motif) receptor 2B (CCR2B) is one of the two isoforms of the receptor for monocyte chemoattractant protein-1 (CCL2), the major chemoattractant for monocytes, involved in an array of chronic inflammatory diseases. Employing the yeast two-hybrid system, we identified the actin-binding protein filamin A (FLNa) as a protein that associates with the carboxyl-terminal tail of CCR2B. Co-immunoprecipitation experiments and in vitro pull down assays demonstrated that FLNa binds constitutively to CCR2B. The colocalization of endogenous CCR2B and filamin A was detected at the surface and in internalized vesicles of THP-1 cells. In addition, CCR2B and FLNa were colocalized in lamellipodia structures of CCR2B-expressing A7 cells. Expression of the receptor in filamin-deficient M2 cells together with siRNA experiments knocking down FLNa in HEK293 cells, demonstrated that lack of FLNa delays the internalization of the receptor. Furthermore, depletion of FLNa in THP-1 monocytes by RNA interference reduced the migration of cells in response to MCP-1. Therefore, FLNa emerges as an important protein for controlling the internalization and spatial localization of the CCR2B receptor in different dynamic membrane structures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Arrestins / metabolism
  • Cell Line, Tumor
  • Cell Membrane / metabolism
  • Cell Movement
  • Chemokine CCL2 / pharmacology
  • Contractile Proteins / metabolism*
  • Filamins
  • Humans
  • Microfilament Proteins / metabolism*
  • Monocytes / cytology
  • Monocytes / drug effects
  • Monocytes / metabolism
  • Protein Binding
  • Protein Transport
  • Receptors, CCR2 / chemistry
  • Receptors, CCR2 / metabolism*
  • beta-Arrestins

Substances

  • Actins
  • Arrestins
  • Chemokine CCL2
  • Contractile Proteins
  • Filamins
  • Microfilament Proteins
  • Receptors, CCR2
  • beta-Arrestins