HUMAN ADP-RIBOSYLATION FACTOR-ACTIVATED PHOSPHATIDYLCHOLINE-SPECIFIC PHOSPHOLIPASE-D DEFINES A NEW AND HIGHLY CONSERVED GENE FAMILY

Activation of phosphatidylcholine-specific phospholipase D (PLD) has b een implicated as a critical step in numerous cellular pathways, inclu ding signal transduction, membrane trafficking, and the regulation of mitosis. We report here the identification of the first human PLD cDNA , which defines a new and highly conserved gene family. Characterizati on of recombinant human PLD1 reveals that it is membrane-associated, s elective for phosphatidylcholine, stimulated by phosphatidyl-inositol 4,5-bisphosphate, activated by the monomeric G-protein ADP-ribosylatio n factor-1, and inhibited by oleate. PLD1 Likely encodes the gene prod uct responsible for the most widely studied endogenous PLD activity.