Enables small GTPase binding activity. Involved in positive regulation of neuron differentiation and positive regulation of protein import into nucleus. Acts upstream of or within cell morphogenesis. Located in cytoplasm and nucleus. Is expressed in brain ventricular layer; liver; and rest of cerebellum marginal layer. Orthologous to human ECT2 (epithelial cell transforming 2). [provided by Alliance of Genome Resources, Apr 2022]