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Structures of the CXCR4 chemokine GPCR with small-molecule and cyclic peptide antagonists

Beili Wu1, Ellen Y T Chien, Clifford D Mol

  • 1Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.

Science (New York, N.Y.)
|October 9, 2010
PubMed

Insights

Structural insights into the chemokine receptor CXCR4 reveal a homodimer crucial for cell migration. These findings impact understanding of cancer metastasis and HIV-1 infection.

Area of Science:

  • Structural Biology
  • Molecular Biology
  • Immunology

Background:

  • Chemokine receptors, such as CXCR4, regulate immune cell migration.
  • CXCR4 is implicated in cancer metastasis and HIV-1 infection.

Purpose of the Study:

  • To determine the crystal structures of CXCR4 bound to antagonists.
  • To elucidate the structural basis of CXCR4 function and ligand interactions.

Main Methods:

  • X-ray crystallography
  • Structure determination at 2.5 to 3.2 angstrom resolution.
  • Analysis of CXCR4-ligand complexes.

Main Results:

  • Five crystal structures of CXCR4 with antagonists IT1t and CVX15 were determined.
  • A consistent homodimer interface involving helices V and VI was observed.
  • CXCR4 ligand-binding sites are distinct from other GPCRs and located near the extracellular surface.

Conclusions:

  • The identified CXCR4 homodimer may regulate receptor signaling.
  • Structural data provides insights into CXCR4 interactions with CXCL12 and HIV-1 gp120.
  • These findings offer a basis for developing novel therapeutics targeting CXCR4.

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