title: A Coronin7 homolog with functions in actin-driven processes.
abstract: Dictyostelium discoideum Coronin7 (DdCRN7) together with human Coronin7 (CRN7) and Pod-1 of Drosophila melanogaster and Caenorhabditis elegans belong to the coronin family of WD-repeat domain-containing proteins. Coronin7 proteins are characterized by two WD-repeat domains that presumably fold into two beta-propeller structures. DdCRN7 shares highest homology with human CRN7, a protein with roles in membrane trafficking. DdCRN7 is present in the cytosol and accumulates in cell surface projections during movement and phago- and pinocytosis. Cells lacking CRN7 have altered chemotaxis and phagocytosis. Furthermore, loss of CRN7 affects the infection process by the pathogen Legionella pneumophila and allows a more efficient internalization of bacteria. To provide a mechanism for CNR7 action, we studied actin-related aspects. We could show that CRN7 binds directly to F-actin and protects actin filaments from depolymerization. CRN7 also associated with F-actin in vivo. It was present in the Triton X-100-insoluble cytoskeleton, colocalized with F-actin, and its distribution was sensitive to drugs affecting the actin cytoskeleton. We propose that the CRN7 role in chemotaxis and phagocytosis is through its effect on the actin cytoskeleton.
authors.affiliation: Institute for Biochemistry I, Center for Molecular Medicine Cologne and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases, Medical Faculty, University of Cologne, 50931 Koeln, Germany.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Shina
authors.forename: Can
authors.initials: C
authors.lastname: Unal
authors.forename: Ludwig
authors.initials: L
authors.lastname: Eichinger
authors.forename: Annette
authors.initials: A
authors.lastname: Müller-Taubenberger
authors.forename: Michael
authors.initials: M
authors.lastname: Schleicher
authors.forename: Michael
authors.initials: M
authors.lastname: Steinert
authors.forename: Angelika A
authors.initials: AA
authors.lastname: Noegel
mesh_terms: D000199:Actins / Q000737:chemistry*; D002448:Cell Adhesion; D002465:Cell Movement; D002633:Chemotaxis; D000242:Cyclic AMP / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D004023:Dictyostelium / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D016952:Legionella pneumophila / Q000378:metabolism; D008840:Microfilament Proteins / Q000737:chemistry*; D008954:Models, Biological; D009154:Mutation; D010587:Phagocytosis; D010873:Pinocytosis; D017434:Protein Structure, Tertiary
chemical_list: D000199:Actins; D008840:Microfilament Proteins; C072061:coronin proteins; D000242:Cyclic AMP; D005982:Glutathione Transferase