Gene cloning, RNA distribution, and functional expression of mCX3CR1, a mouse chemotactic receptor for the CX3C chemokine fractalkine

Biochem Biophys Res Commun. 1998 Dec 30;253(3):728-32. doi: 10.1006/bbrc.1998.9849.


Human fractalkine and its apparent murine counterpart neurotactin are the only members identified so far of the CX3C subfamily of chemokines. Recently, a human fractalkine receptor was identified and named CX3CR1. Here we have identified a mouse counterpart of this receptor. The receptor was identified by analysis of a mouse genomic clone named PC2 isolated by homology hybridization using CX3CR1 as probe. Clone PC2 has a 354-codon open reading frame that has 83% amino acid identity to CX3CR1. PC2 RNA was abundant in brain and lung and comparatively less abundant in lung, liver, kidney, testis, and peripheral blood leukocytes, a pattern similar to that found for CX3CR1. The recombinant fractalkine, but no other chemokines tested, induced chemotaxis and transient increases in [Ca2+]i in HEK 293 cells transfected with PC2, whereas untransfected cells did not respond. Furthermore, fractalkine bound specifically to the transfected cells (Kd=4 nM). Thus, fractalkine is a functional ligand for this receptor and we propose to name it mCX3CR1 for murine CX3C chemokine receptor 1.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • CX3C Chemokine Receptor 1
  • Calcium / metabolism
  • Cell Line
  • Chemokine CX3CL1
  • Chemokines, CX3C*
  • Chemokines, CXC / metabolism*
  • Cloning, Molecular
  • Ligands
  • Membrane Proteins / metabolism*
  • Mice
  • Molecular Sequence Data
  • RNA / analysis
  • Receptors, Cytokine / genetics*
  • Receptors, Cytokine / metabolism
  • Receptors, HIV / genetics*
  • Receptors, HIV / metabolism
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Tissue Distribution


  • CX3C Chemokine Receptor 1
  • CX3CL1 protein, human
  • Chemokine CX3CL1
  • Chemokines, CX3C
  • Chemokines, CXC
  • Cx3cl1 protein, mouse
  • Ligands
  • Membrane Proteins
  • Receptors, Cytokine
  • Receptors, HIV
  • Recombinant Proteins
  • RNA
  • Calcium

Associated data

  • GENBANK/AF074912