May play a role in actin cytoskeleton reorganization in different tissues since its activation induces formation of actin stress fibers. It works as a guanine nucleotide exchange factor for Rho family of small GTPases. Links specifically G alpha q/11-coupled receptors to RHOA activation (By similarity). May be an important regulator of processes involved in axon and dendrite formation. In neurons seems to be an exchange factor primarily for RAC1. Involved in skeletal myogenesis. Interacts with activated GNAQ and GNA11 (By similarity). Interacts (via the DH domain) with BVES (via the C-terminus cytoplasmic tail). Interacts with RHOA, CDC42 and RAC1. Highly colocalizes with actin regions. Highly expressed in excitable tissues, such as brain, heart and muscle. Elevated expression in hippocampus and cerebellum. Transcriptionally up-regulated during myogenic differentiation and down-regulated during adipogenic differentiation. Protein levels up-regulated during retinoic acid and dibutyric cAMP-induced outgrowth of neurites. The guanine nucleotide exchange activity is autoinhibited by the PH domain.