GDE1 (glycerophosphodiester phosphodiesterase 1) catalyzes the hydrolysis of GroPIns (1-(sn-glycero-3-O-phosphonato)-1D-myo-inositol; glycerophosphoinositol) to G3P (glycerol-3-phosphate) and Ins (inositol). Experimental studies of the homologous rat enzyme have shown it to be associated with cellular membranes, to have a strong preference for glycerophosphoinositol over glycerophosphocholine as a substrate, and to be stimulated by G protein agonists, suggesting a possible role for GDE1 in signaling by G protein-coupled receptors (Zheng et al. 2000, 2003). Modeling studies with the human protein have been interpreted to suggest localization specifically to the plasma membrane (Bachmann et al. 2006).