Enables actin filament binding activity. Involved in positive regulation of JNK cascade and regulation of cell shape. Acts upstream of or within positive regulation of JUN kinase activity. Predicted to be located in filopodium and lamellipodium. Predicted to be active in cytoplasm. Human ortholog(s) of this gene implicated in Charcot-Marie-Tooth disease type 4H. Orthologous to human FGD4 (FYVE, RhoGEF and PH domain containing 4). [provided by Alliance of Genome Resources, Apr 2022]