Enables Rho GDP-dissociation inhibitor activity. Involved in semaphorin-plexin signaling pathway. Acts upstream of or within Rho protein signal transduction and regulation of protein localization. Located in immunological synapse and nucleus. Is expressed in brain and heart. Used to study nephrotic syndrome. Human ortholog(s) of this gene implicated in nephrotic syndrome type 8. Orthologous to human ARHGDIA (Rho GDP dissociation inhibitor alpha). [provided by Alliance of Genome Resources, Apr 2022]