UniProt Summary: Has glycerophosphoinositol phosphodiesterase activity. Hydrolyzes lysoglycerophospholipids to produce lysophosphatidic acid (LPA) and the corresponding amines. Has little or no activity towards glycerophosphocholine. GDE1 activity can be modulated by G-protein signaling pathways (By similarity). {ECO:0000250|UniProtKB:Q9JL55, ECO:0000250|UniProtKB:Q9JL56}.