title: The Arf-GEF Schizo/Loner regulates N-cadherin to induce fusion competence of Drosophila myoblasts.
abstract: Myoblast fusion is a key process in multinucleated muscle formation. Prior to fusion, myoblasts recognize and adhere to each other with the aid of cell-adhesion proteins integrated into the membrane. Their intracellular domains participate in signal transduction by binding to cytoplasmic proteins. Here we identified the calcium-dependent cell-adhesion protein N-cadherin as the binding partner of the guanine-nucleotide exchange factor Schizo/Loner in Drosophila melanogaster. N-cadherin was expressed in founder cells and fusion-competent myoblasts of Drosophila during the first fusion phase. Our genetic analyses demonstrated that the myoblast fusion defect of schizo/loner mutants is rescued in part by the loss-of-function mutation of N-cadherin, which suggests that Schizo/Loner is a negative regulator of N-cadherin. Based on our findings, we propose a model where N-cadherin must be removed from the myoblast membrane to induce a protein-free zone at the cell-cell contact point to permit fusion.
authors.affiliation: Fachbereich Biologie, Entwicklungsbiologie, Philipps-Universität Marburg, Karl-von-Frisch Str. 8, D-35043 Marburg, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Dottermusch-Heidel
authors.forename: Verena
authors.initials: V
authors.lastname: Groth
authors.forename: Lothar
authors.initials: L
authors.lastname: Beck
authors.forename: Susanne-Filiz
authors.initials: SF
authors.lastname: Önel
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D030801:Animals, Genetically Modified; D001665:Binding Sites / Q000235:genetics; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D002459:Cell Fusion; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D005260:Female; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D009154:Mutation; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism*; D011485:Protein Binding; D020798:Two-Hybrid System Techniques
chemical_list: C570800:CadN protein, Drosophila; D015820:Cadherins; D029721:Drosophila Proteins; D020662:Guanine Nucleotide Exchange Factors; D008164:Luminescent Proteins; C478493:Siz protein, Drosophila; D020823:ADP-Ribosylation Factor 1