title: Characterization of Microfibrillar-associated Protein 4 (MFAP4) as a Tropoelastin- and Fibrillin-binding Protein Involved in Elastic Fiber Formation.
abstract: MFAP4 (microfibrillar-associated protein 4) is an extracellular glycoprotein found in elastic fibers without a clearly defined role in elastic fiber assembly. In the present study, we characterized molecular interactions between MFAP4 and elastic fiber components. We established that MFAP4 primarily assembles into trimeric and hexameric structures of homodimers. Binding analysis revealed that MFAP4 specifically binds tropoelastin and fibrillin-1 and -2, as well as the elastin cross-linking amino acid desmosine, and that it co-localizes with fibrillin-1-positive fibers in vivo. Site-directed mutagenesis disclosed residues Phe(241) and Ser(203) in MFAP4 as being crucial for type I collagen, elastin, and tropoelastin binding. Furthermore, we found that MFAP4 actively promotes tropoelastin self-assembly. In conclusion, our data identify MFAP4 as a new ligand of microfibrils and tropoelastin involved in proper elastic fiber organization.
authors.affiliation: From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark.
authors.forename: Bartosz
authors.initials: B
authors.lastname: Pilecki
authors.affiliation: From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark.
authors.forename: Anne T
authors.initials: AT
authors.lastname: Holm
authors.affiliation: From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Schlosser
authors.affiliation: From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark.
authors.forename: Jesper B
authors.initials: JB
authors.lastname: Moeller
authors.affiliation: the Center for Biochemistry, Faculty of Medicine and.
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Wohl
authors.affiliation: the Center for Biochemistry, Faculty of Medicine and.
authors.forename: Alexandra V
authors.initials: AV
authors.lastname: Zuk
authors.affiliation: the Center for Biochemistry, Faculty of Medicine and the Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany.
authors.forename: Stefanie E
authors.initials: SE
authors.lastname: Heumüller
authors.affiliation: the Department of Infection, Immunity and Inflammation, and Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 9HN, United Kingdom, and.
authors.forename: Russell
authors.initials: R
authors.lastname: Wallis
authors.affiliation: From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark, the Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, 5000 Odense C, Denmark.
authors.forename: Soren K
authors.initials: SK
authors.lastname: Moestrup
authors.affiliation: the Center for Biochemistry, Faculty of Medicine and the Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Sengle
authors.affiliation: From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark.
authors.forename: Uffe
authors.initials: U
authors.lastname: Holmskov
authors.affiliation: From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark, glsorensen@health.sdu.dk.
authors.forename: Grith L
authors.initials: GL
authors.lastname: Sorensen
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003895:Desmosine / Q000378:metabolism*; D004547:Elastic Tissue / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000071838:Fibrillin-1; D000071837:Fibrillins; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008297:Male; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D020894:Microfibrils / Q000378:metabolism*; D008840:Microfilament Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055503:Protein Multimerization; D021381:Protein Transport; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014333:Tropoelastin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D054392:Adipokines
chemical_list: D002352:Carrier Proteins; D003895:Desmosine; D016326:Extracellular Matrix Proteins; D000071838:Fibrillin-1; D000071837:Fibrillins; D006023:Glycoproteins; D008024:Ligands; D008840:Microfilament Proteins; D010446:Peptide Fragments; D020033:Protein Isoforms; D011994:Recombinant Proteins; D014333:Tropoelastin; C000605722:FBN1 protein, human; D054392:Adipokines; C000605724:Fbn1 protein, mouse; C400752:MFAP4 protein, human; C000600072:MFAP4 protein, mouse
keywords: analytical ultracentrifugation; calcium-binding protein; elastin; fibrillin; microfibrillar-associated protein 4; site-directed mutagenesis; surface plasmon resonance (SPR)