Cx3cl1

Function

Chemokine that acts as a ligand for both CX3CR1 and integrins ITGAV:ITGB3 and ITGA4:ITGB1 (PubMed:10187784, PubMed:18971423). The CX3CR1-CX3CL1 signaling exerts distinct functions in different tissue compartments, such as immune response, inflammation, cell adhesion and chemotaxis (PubMed:10187784, PubMed:10382755, PubMed:18971423, PubMed:9177350). Regulates leukocyte adhesion and migration processes at the endothelium (PubMed:10382755, PubMed:9177350). Can activate integrins in both a CX3CR1-dependent and CX3CR1-independent manner (By similarity). In the presence of CX3CR1, activates integrins by binding to the classical ligand-binding site (site 1) in integrins (By similarity). In the absence of CX3CR1, binds to a second site (site 2) in integrins which is distinct from site 1 and enhances the binding of other integrin ligands to site 1 (By similarity).

Processed fractalkine

The soluble form is chemotactic for T-cells and monocytes, but not for neutrophils.

Fractalkine

The membrane-bound form promotes adhesion of those leukocytes to endothelial cells.

Post-translational modifications

A soluble short 80 kDa form may be released by proteolytic cleavage from the long membrane-anchored form.

Sequence Similarities

Belongs to the intercrine delta family.

Tissue Specificity

Highest levels in brain (PubMed:10508268, PubMed:9177350, PubMed:9479488, PubMed:9845323). Lower levels in kidney, heart and lung (PubMed:10508268, PubMed:9177350, PubMed:9479488). Also found in skeletal muscle and testis (PubMed:9177350, PubMed:9479488). Highly expressed in lesional smooth muscle cells, but not macrophages (PubMed:12569158). Low levels of ABCD-3 mRNA were also found in anti-CD40-stimulated splenic B-cells, but not in resting B-cells. Also expressed in dendritic cells (PubMed:10508268).

Cellular localization

• Cell membrane
• Single-pass type I membrane protein
• Processed fractalkine
• Secreted

Alternative names

Cx3c, Fkn, Scyd1, Cx3cl1, Fractalkine, FK, ABCD-3, C-X3-C motif chemokine 1, CX3C membrane-anchored chemokine, Neurotactin, Small-inducible cytokine D1

Database links

swissprot:O35188 entrezGene:20312

Other research areas

• Immuno-oncology