title: Regulation of the actin cytoskeleton by an interaction of IQGAP related protein GAPA with filamin and cortexillin I.
abstract: Filamin and Cortexillin are F-actin crosslinking proteins in Dictyostelium discoideum allowing actin filaments to form three-dimensional networks. GAPA, an IQGAP related protein, is required for cytokinesis and localizes to the cleavage furrow during cytokinesis. Here we describe a novel interaction with Filamin which is required for cytokinesis and regulation of the F-actin content. The interaction occurs through the actin binding domain of Filamin and the GRD domain of GAPA. A similar interaction takes place with Cortexillin I. We further report that Filamin associates with Rac1a implying that filamin might act as a scaffold for small GTPases. Filamin and activated Rac associate with GAPA to regulate actin remodelling. Overexpression of filamin and GAPA in the various strains suggests that GAPA regulates the actin cytoskeleton through interaction with Filamin and that it controls cytokinesis through association with Filamin and Cortexillin.
authors.affiliation: Medical Faculty, Institute of Biochemistry I, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Köln, Germany.
authors.forename: Subhanjan
authors.initials: S
authors.lastname: Mondal
authors.forename: Bhagyashri
authors.initials: B
authors.lastname: Burgute
authors.forename: Daniela
authors.initials: D
authors.lastname: Rieger
authors.forename: Rolf
authors.initials: R
authors.lastname: Müller
authors.forename: Francisco
authors.initials: F
authors.lastname: Rivero
authors.forename: Jan
authors.initials: J
authors.lastname: Faix
authors.forename: Michael
authors.initials: M
authors.lastname: Schleicher
authors.forename: Angelika A
authors.initials: AA
authors.lastname: Noegel
mesh_terms: D000199:Actins / Q000378:metabolism; D003285:Contractile Proteins / Q000235:genetics / Q000378:metabolism*; D048749:Cytokinesis; D003599:Cytoskeleton / Q000378:metabolism*; D004023:Dictyostelium / Q000235:genetics / Q000378:metabolism; D064448:Filamins; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009154:Mutation; D011485:Protein Binding; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D011554:Pseudopodia / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D020703:ras GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D003285:Contractile Proteins; D064448:Filamins; D008840:Microfilament Proteins; D015800:Protozoan Proteins; C101109:ctxA protein, Dictyostelium discoideum; D020703:ras GTPase-Activating Proteins; D049452:Green Fluorescent Proteins