Small GTPase. Negatively regulates the transcription regulation activity of the APBB1/FE65-APP complex via its interaction with APBB1/FE65 (By similarity). Forms a ternary complex with CAPON and NOS1. Component of a complex, at least composed of APBB1, RASD1/DEXRAS1 and APP. Interacts with APBB1/FE65 (By similarity). Expressed in a variety of tissues including heart, cardiovascular tissues, brain, placenta, lung, liver, skeletal muscle, kidney, pancreas, gastrointestinal and reproductive tissues. By dexamethasone. S-nitrosylation stimulates guanine-nucleotide exchange activity. Belongs to the small GTPase superfamily. RasD family.