Glycerophosphodiester phosphodiesterase domain of mammalian glycerophosphodiester phosphodiesterase GDE1 and similar proteinsThis subfamily corresponds to the glycerophosphodiester phosphodiesterase domain (GDPD) present in mammalian GDE1 (also known as MIR16, membrane interacting protein of RGS16) and their metazoan homologs. GDE1 is widely expressed in mammalian tissues, including the heart, brain, liver, and kidney. It shows sequence homology to bacterial glycerophosphodiester phosphodiesterases (GP-GDEs, EC 22.214.171.124), which catalyzes the hydrolysis of various glycerophosphodiesters, and produce sn-glycerol-3-phosphate (G3P) and the corresponding alcohols. GDE1 has been characterized as GPI-GDE (EC 126.96.36.199) that selectively hydrolyzes extracellular glycerophosphoinositol (GPI) to generate glycerol phosphate and inositol. It functions as an integral membrane-bound glycoprotein interacting with regulator of G protein signaling protein RGS16, and is modulated by G protein-coupled receptor (GPCR) signaling. In addition, GDE1 may interact with PRA1 domain family, member 2 (PRAF2, also known as JM4), which is an interacting protein of the G protein-coupled chemokine receptor CCR5. The catalytic activity, which is dependent on the integrity of the GDPD domain, is required for GDE1 cellular function.