GDE3, also known as glycerophosphodiester phosphodiesterase 3, glycerophosphodiester phosphodiesterase domain containing 2 (GDPD2) or osteoblast differentiation promoting factor (OBDPF), is a 539 amino acid protein belonging to the glycerophosphoryl diester phosphodiesterase family. Possessing glycerophosphoinositol inositolphosphodiesterase activity, GDE3 hydrolyzes glycerophosphoinositol to form inositol 1-phosphate and glycerol, and is suggested to play a role in Actin cytoskeleton remodeling and osteoblast differentiation and growth. A multi-pass membrane protein, GDE3 localizes to cell membrane and cytoplasm, and colocalizes with actin in the cytoskeleton. GDE3 contains one GDPD domain, binds calcium as a cofactor and is encoded by a gene mapping to human chromosome Xq13.1.