title: The conserved ADAMTS-like protein lonely heart mediates matrix formation and cardiac tissue integrity.
abstract: Here we report on the identification and functional characterization of the ADAMTS-like homolog lonely heart (loh) in Drosophila melanogaster. Loh displays all hallmarks of ADAMTSL proteins including several thrombospondin type 1 repeats (TSR1), and acts in concert with the collagen Pericardin (Prc). Loss of either loh or prc causes progressive cardiac damage peaking in the abolishment of heart function. We show that both proteins are integral components of the cardiac ECM mediating cellular adhesion between the cardiac tube and the pericardial cells. Loss of ECM integrity leads to an altered myo-fibrillar organization in cardiac cells massively influencing heart beat pattern. We show evidence that Loh acts as a secreted receptor for Prc and works as a crucial determinant to allow the formation of a cell and tissue specific ECM, while it does not influence the accumulation of other matrix proteins like Nidogen or Perlecan. Our findings demonstrate that the function of ADAMTS-like proteins is conserved throughout evolution and reveal a previously unknown interaction of these proteins with collagens.
authors.affiliation: University of Osnabrueck, Department of Zoology and Developmental Biology, Osnabrueck, Germany.
authors.forename: Maik
authors.initials: M
authors.lastname: Drechsler
authors.forename: Ariane C
authors.initials: AC
authors.lastname: Schmidt
authors.forename: Heiko
authors.initials: H
authors.lastname: Meyer
authors.forename: Achim
authors.initials: A
authors.lastname: Paululat
mesh_terms: D051722:ADAM Proteins / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion; D003094:Collagen / Q000235:genetics / Q000378:metabolism*; D024141:Collagen Type IV / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D019143:Evolution, Molecular; D005109:Extracellular Matrix / Q000235:genetics / Q000648:ultrastructure; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure; D009210:Myofibrils / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D019699:Thrombospondins / Q000235:genetics / Q000378:metabolism
chemical_list: D024141:Collagen Type IV; D029721:Drosophila Proteins; D016326:Extracellular Matrix Proteins; C585455:Loh protein, Drosophila; D008562:Membrane Glycoproteins; C585456:Prc protein, Drosophila; D019699:Thrombospondins; C029967:nidogen; D003094:Collagen; D051722:ADAM Proteins; D008666:Metalloendopeptidases