| Regulation of expression of phospholipase D 1 and D 2 by PEA 15 , a novel protein that interacts with them . ^^^ The PLD 1 interacting site on PEA 15 consists of part of the death effector domain domain plus additional C terminal flanking sequences , whereas the PEA 15 interacting site on PLD 1 overlaps the previously identified RhoA interacting site . ^^^ PEA 15 did not affect basal or stimulated in vitro PLD 1 enzymatic activation . ^^^ However , co expression of PEA 15 increased levels of PLD 1 activity . ^^^ This increased activation correlated with higher PLD 1 protein expression levels , as marked by faster accumulation and longer persistence of PLD 1 when PEA 15 was present . ^^^ |