Using phospholipase D1 (PLD1)-overexpressing PC12 (PLD1-PC12) cells, the regulatory roles of PLD1 on ATP-induced currents were investigated. In control and PLD1-PC12 cells, ATP increased PLD activity in an external Ca2⁢ dependent manner. PLD activity stimulated by ATP was substantially larger in PLD1-PC12 cells than in control cells. In whole-cell voltage-clamp mode, ATP induced transient inward and outward currents. The outward currents inhibited by TEA or charybdotoxin were significantly larger in PLD1-PC12 cells than in control cells. The inward currents known as Ca2⁢ permeable nonselective cation currents were also larger in PLD1-PC12 cells than in control cells. However, the difference between the two groups of cells disappeared in Ca2⁢-free external solution, where ATP did not activate PLD. Finally, ATP-induced 45Ca uptakes were also larger in PLD1-PC12 cells than in control cells. These results suggest that PLD enhances ATP-induced Ca2⁢ influx via Ca2⁢ permeable nonselective cation channels and increases subsequent Ca2⁢-activated K⁢ currents in PC12 cells.