Predicted to enable GTPase activator activity. Predicted to be involved in negative regulation of endoplasmic reticulum calcium ion concentration; positive regulation of GTPase activity; and positive regulation of mitochondrial calcium ion concentration. Predicted to be located in endoplasmic reticulum and mitochondrion. Predicted to be active in cytosol. Is expressed in several structures, including central nervous system; dorsal root ganglion; glans of male genital tubercle; liver; and retina nuclear layer. Orthologous to human RAP1GDS1 (Rap1 GTPase-GDP dissociation stimulator 1). [provided by Alliance of Genome Resources, Apr 2022]