Cloning and characterization of human PLD1 promoter region

Abstract

Phospholipase D (PLD) activity has been implicated in the regulation of membrane trafficking, superoxide generation and cytoskeletal remodelling. Phospholipase D (PLD) activity is elevated in response to most mitogenic signals. Especially, PLD1 is a downstream target of the Ras/RalA GTPase cascade implicated in mitogenic and oncogenic signaling. PLD1 promoter region was cloned from human genomic DNA and analyzed. 27kb sized intervening sequence was found between the promoter region and transcriptional initiation site of PLD1. 2.6kb sized promoter region was amplified from human genomic DNA. PLD1 promoter reporter gene was constructed and analyzed by transient transfection and firefly luciferase assay. Several factors which were confirmed to be induced in human stomach cancer tissue were cloned from human fetal cDNA library and investigated for its transactivation of PLD1 promoter. Also, several deletion construcs of PLD1 promoter were made and analyzed using some factors which were found to be induced in human gastric cancer. Among those factors, PDEF was the most potent transactivator of PLD1 promoter in KATO III cells.