title: Structural basis of the interaction between chemokine stromal cell-derived factor-1/CXCL12 and its G-protein-coupled receptor CXCR4.
abstract: The chemokine stromal cell-derived factor-1 (SDF-1/CXCL12) and its G-protein-coupled receptor (GPCR) CXCR4 play fundamental roles in many physiological processes, and CXCR4 is a drug target for various diseases such as cancer metastasis and human immunodeficiency virus, type 1, infection. However, almost no structural information about the SDF-1-CXCR4 interaction is available, mainly because of the difficulties in expression, purification, and crystallization of CXCR4. In this study, an extensive investigation of the preparation of CXCR4 and optimization of the experimental conditions enables NMR analyses of the interaction between the full-length CXCR4 and SDF-1. We demonstrated that the binding of an extended surface on the SDF-1 beta-sheet, 50-s loop, and N-loop to the CXCR4 extracellular region and that of the SDF-1 N terminus to the CXCR4 transmembrane region, which is critical for G-protein signaling, take place independently by methyl-utilizing transferred cross-saturation experiments along with the usage of the CXCR4-selective antagonist AMD3100. Furthermore, based upon the data, we conclude that the highly dynamic SDF-1 N terminus in the 1st step bound state plays a crucial role in efficiently searching the deeply buried binding pocket in the CXCR4 transmembrane region by the "fly-casting" mechanism. This is the first structural analyses of the interaction between a full-length GPCR and its chemokine, and our methodology would be applicable to other GPCR-ligand systems, for which the structural studies are still challenging.
authors.affiliation: Graduate School of Pharmaceutical Sciences, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kofuku
authors.forename: Chie
authors.initials: C
authors.lastname: Yoshiura
authors.forename: Takumi
authors.initials: T
authors.lastname: Ueda
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Terasawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hirai
authors.forename: Sae
authors.initials: S
authors.lastname: Tominaga
authors.forename: Masako
authors.initials: M
authors.lastname: Hirose
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Maeda
authors.forename: Hideo
authors.initials: H
authors.lastname: Takahashi
authors.forename: Yuya
authors.initials: Y
authors.lastname: Terashima
authors.forename: Kouji
authors.initials: K
authors.lastname: Matsushima
authors.forename: Ichio
authors.initials: I
authors.lastname: Shimada
mesh_terms: D054377:Chemokine CXCL12 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D017434:Protein Structure, Tertiary; D019718:Receptors, CXCR4 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D054377:Chemokine CXCL12; D019718:Receptors, CXCR4