Identification of a motif in the carboxyl terminus of CXCR2 that is involved in adaptin 2 binding and receptor internalization

Biochemistry. 2001 Jan 23;40(3):791-800. doi: 10.1021/bi001661b.


Agonist treatment of cells expressing the chemokine receptor, CXCR2, induces receptor phosphorylation and internalization through a dynamin-dependent mechanism. In the present study, we demonstrate that a carboxyl terminus-truncated mutant of CXCR2 (331T), which no longer undergoes agonist-induced phosphorylation, continues to undergo ligand-induced internalization in HEK293 cells. This mutant receptor exhibits reduced association with beta-arrestin 1 but continues to exhibit association with adaptin 2 alpha and beta subunits. Replacing Leu320-321 and/or Ile323-Leu324 with Ala (LL320,321AA, IL323,324AA, and LLIL320,321,323,324AAAA) in wild-type CXCR2 or 331T causes little change in ligand binding and signaling through Ca(2+) mobilization but greatly impairs the agonist-induced receptor sequestration and ligand-mediated chemotaxis. The LL320,321AA, IL323,324AA, and LLIL320,321,323,324AAAA mutants of CXCR2 exhibit normal binding to beta-arrestin 1 but exhibit decreased binding to adaptin 2alpha and beta. These data demonstrate a role for the LLKIL motif in the carboxyl terminus of CXCR2 in receptor internalization and cell chemotaxis and imply a role for adaptin 2 in the endocytosis of CXCR2.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adaptor Protein Complex alpha Subunits
  • Adaptor Proteins, Vesicular Transport
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Arrestins / metabolism
  • Arrestins / physiology
  • Cell Line
  • Chemotaxis / genetics
  • Chemotaxis / physiology
  • Embryo, Mammalian
  • Humans
  • Kidney
  • Ligands
  • Membrane Proteins / metabolism*
  • Membrane Proteins / physiology
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Peptide Fragments / chemistry
  • Peptide Fragments / metabolism*
  • Peptide Fragments / physiology
  • Rats
  • Receptors, Interleukin-8B / agonists
  • Receptors, Interleukin-8B / biosynthesis
  • Receptors, Interleukin-8B / genetics
  • Receptors, Interleukin-8B / metabolism*
  • Signal Transduction / genetics
  • Transfection
  • Tumor Cells, Cultured
  • beta-Arrestin 1
  • beta-Arrestins


  • ARRB1 protein, human
  • Adaptor Protein Complex alpha Subunits
  • Adaptor Proteins, Vesicular Transport
  • Arrb1 protein, rat
  • Arrestins
  • Ligands
  • Membrane Proteins
  • Peptide Fragments
  • Receptors, Interleukin-8B
  • beta-Arrestin 1
  • beta-Arrestins