PMID: 18799424

Authors:

Veldkamp CT, Seibert C, Peterson FC, De la Cruz NB, Haugner JC 3rd, Basnet H, Sakmar TP, Volkman BF

Title:

Structural basis of CXCR4 sulfotyrosine recognition by the chemokine SDF-1/CXCL12.

Journal:

Sci Signal. 2008 Sep 16;1(37):ra4.

Abstract:

Stem cell homing and breast cancer metastasis are orchestrated by the chemokine stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4. Here, we report the nuclear magnetic resonance structure of a constitutively dimeric SDF-1 in complex with a CXCR4 fragment that contains three sulfotyrosine residues important for a high-affinity ligand-receptor interaction. CXCR4 bridged the SDF-1 dimer interface so that sulfotyrosines sTyr7 and sTyr12 of CXCR4 occupied positively charged clefts on opposing chemokine subunits. Dimeric SDF-1 induced intracellular Ca2+ mobilization but had no chemotactic activity; instead, it prevented native SDF-1-induced chemotaxis, suggesting that it acted as a potent partial agonist. Our work elucidates the structural basis for sulfotyrosine recognition in the chemokine-receptor interaction and suggests a strategy for CXCR4-targeted drug development.