title: Macrophage Migration Inhibitory Factor-CXCR4 Receptor Interactions: EVIDENCE FOR PARTIAL ALLOSTERIC AGONISM IN COMPARISON WITH CXCL12 CHEMOKINE.
abstract: An emerging number of non-chemokine mediators are found to bind to classical chemokine receptors and to elicit critical biological responses. Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine that exhibits chemokine-like activities through non-cognate interactions with the chemokine receptors CXCR2 and CXCR4, in addition to activating the type II receptor CD74. Activation of the MIF-CXCR2 and -CXCR4 axes promotes leukocyte recruitment, mediating the exacerbating role of MIF in atherosclerosis and contributing to the wealth of other MIF biological activities. Although the structural basis of the MIF-CXCR2 interaction has been well studied and was found to engage a pseudo-ELR and an N-like loop motif, nothing is known about the regions of CXCR4 and MIF that are involved in binding to each other. Using a genetic strain of Saccharomyces cerevisiae that expresses a functional CXCR4 receptor, site-specific mutagenesis, hybrid CXCR3/CXCR4 receptors, pharmacological reagents, peptide array analysis, chemotaxis, fluorescence spectroscopy, and circular dichroism, we provide novel molecular information about the structural elements that govern the interaction between MIF and CXCR4. The data identify similarities with classical chemokine-receptor interactions but also provide evidence for a partial allosteric agonist compared with CXCL12 that is possible due to the two binding sites of CXCR4.
authors.affiliation: From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520.
authors.forename: Deepa
authors.initials: D
authors.lastname: Rajasekaran
authors.affiliation: the Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälische Technische Hochschule (RWTH), Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Gröning
authors.affiliation: the Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälische Technische Hochschule (RWTH), Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany, Vascular Biology, Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Feodor-Lynen-Strasse 17, and.
authors.forename: Corinna
authors.initials: C
authors.lastname: Schmitz
authors.affiliation: From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520.
authors.forename: Swen
authors.initials: S
authors.lastname: Zierow
authors.affiliation: From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520.
authors.forename: Natalie
authors.initials: N
authors.lastname: Drucker
authors.affiliation: the Division of Peptide Biochemistry, Technische Universität München, 85354 Freising-Weihenstephan, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Bakou
authors.affiliation: the Division of Peptide Biochemistry, Technische Universität München, 85354 Freising-Weihenstephan, Germany.
authors.forename: Kristian
authors.initials: K
authors.lastname: Kohl
authors.affiliation: the Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälische Technische Hochschule (RWTH), Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Mertens
authors.affiliation: the Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälische Technische Hochschule (RWTH), Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Hongqi
authors.initials: H
authors.lastname: Lue
authors.affiliation: the Institute for Cardiovascular Prevention, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Pettenkofer Strasse 8, 80336 Munich, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Weber
authors.affiliation: the Center for Molecular Imaging, Departments of Radiology, Biomedical Engineering, and Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan 48109.
authors.forename: Annie
authors.initials: A
authors.lastname: Xiao
authors.affiliation: the Center for Molecular Imaging, Departments of Radiology, Biomedical Engineering, and Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan 48109.
authors.forename: Gary
authors.initials: G
authors.lastname: Luker
authors.affiliation: the Division of Peptide Biochemistry, Technische Universität München, 85354 Freising-Weihenstephan, Germany, akapurniotu@wzw.tum.de.
authors.forename: Aphrodite
authors.initials: A
authors.lastname: Kapurniotu
authors.affiliation: From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, elias.lolis@yale.edu.
authors.forename: Elias
authors.initials: E
authors.lastname: Lolis
authors.affiliation: the Institute of Biochemistry and Molecular Cell Biology, Rheinisch-Westfälische Technische Hochschule (RWTH), Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany, Vascular Biology, Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-University of Munich, Feodor-Lynen-Strasse 17, and the Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany juergen.bernhagen@med.uni-muenchen.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Bernhagen
mesh_terms: D000494:Allosteric Regulation; D000818:Animals; D016466:CHO Cells; D054377:Chemokine CXCL12 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008263:Macrophage Migration-Inhibitory Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: C515255:CXCL12 protein, human; C527276:CXCR4 protein, human; D054377:Chemokine CXCL12; D008263:Macrophage Migration-Inhibitory Factors; D019718:Receptors, CXCR4; D011994:Recombinant Proteins; D019746:Intramolecular Oxidoreductases; C515598:MIF protein, human
keywords: G protein-coupled receptor (GPCR); chemokine; cytokine; protein mapping; protein-protein interaction; structure-function