Plays a role in directed cell migration by regulating the activation and subcellular location of RAC1 (PubMed:25074804, PubMed:25925950). Increases the presence of activated RAC1 at the leading edge of migrating cells (PubMed:25074804, PubMed:25925950). Required for normal organization of the cytoskeleton, including the actin cytoskeleton, microtubules and the vimentin intermediate filaments (PubMed:27178841). Required for normal cell proliferation, cell migration, and normal formation of lamellipodia (PubMed:27178841). Plays a role in endoplasmic reticulum-associated endosome fission: localizes to endosome membrane tubules and promotes recruitment of TMCC1, leading to recruitment of the endoplasmic reticulum to endosome tubules for fission. Endosome membrane fission of early and late endosomes is essential to separate regions destined for lysosomal degradation from carriers to be recycled to the plasma membrane (By similarity). Required for normal distribution of mitochondria within cells (PubMed:27178841). Homotrimer (By similarity). Binds F-actin (PubMed:22364218). Interacts with RCC2 (PubMed:25074804). Interacts preferentially with nucleotide-free and GDP-bound RAC1 (PubMed:25074804). Interacts with VIM (via head domain) (PubMed:27178841). Interacts with MICAL2; this interaction recruits MICAL2 to the actin filaments (By similarity). Colocalizes with the actin cytoskeleton in the cytosol, and especially in the cell cortex (PubMed:19651142, PubMed:22364218, PubMed:25074804, PubMed:27178841). Colocalizes with F-actin at the leading edge of lamellipodia (PubMed:22364218). Partially colocalizes with microtubules and vimentin intermediate filaments (PubMed:27178841). Localizes to endosome membrane tubules/buds (By similarity). Detected in skeletal muscle (at protein level) (PubMed:19651142). Detected in fibroblasts (at protein level) (PubMed:27178841). Ubiquitous (PubMed:9778037). The C-terminal coiled-coil domain is essential for cortical membrane localization and oligomerization. No visible phenotype (PubMed:27178841). Fibroblasts from mutant mice display a disordered actin cytoskeleton with a reduced width of the actin stress fibers. Likewise, these cells have several microtubule-organizing centers (MTOCs) and a disordered microbutule network (PubMed:27178841). Belongs to the WD repeat coronin family.