PHORBOL ESTER-SENSITIVE PHOSPHOLIPASE-D IS MAINLY LOCALIZED IN THE ENDOPLASMIC-RETICULUM OF BHK CELLS

The localization of phorbol ester-sensitive phospholipase D (PLD) in b aby hamster kidney cells has been investigated by determining the subc ellular distribution of the phosphatidylbutanol produced when the cell s are incubated with phorbol 12-myristate 13-acetate and n-butanol. Re sults derived by isolation of plasma membrane vesicles from intact cel ls or by subcellular fractionation on a sucrose density gradient sugge st the PLD is specific for phosphatidylcholine and its primary site of action is not the plasma membrane but the endoplasmic reticulum.