A Coronin7 homolog with functions in actin-driven processes.
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.
Shina
Maria C
MC
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.
Unal
Can
C
Eichinger
Ludwig
L
Müller-Taubenberger
Annette
A
Schleicher
Michael
M
Steinert
Michael
M
Noegel
Angelika A
AA
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
D000199:Actins; D008840:Microfilament Proteins; C072061:coronin proteins; D000242:Cyclic AMP; D005982:Glutathione Transferase