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Hydrogen peroxide‐induced phospholipase D 2 activation in lymphocytic leukemic L1210 cells
Author(s) -
Lee Byoung Dae,
Kim Jae Ho,
Lee Sang Do,
Kim Yong,
Suh PannGhill,
Ryu Sung Ho
Publication year - 2000
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.67.5.630
Subject(s) - phospholipase d , pld2 , egta , extracellular , hydrogen peroxide , phorbol , protein kinase c , transfection , phospholipase , biology , microbiology and biotechnology , biochemistry , kinase , chemistry , calcium , phosphatidic acid , signal transduction , enzyme , phospholipid , organic chemistry , membrane , gene
Extracellular hydrogen peroxide (H 2 O 2 ) has been implicated in the activation of phospholipase D (PLD). However, it was still unclear how this activation occurs and what the molecular identity of the H 2 O 2 ‐stimulated PLD isozyme is. This study shows that H 2 O 2 potently increases the PLD activity in mouse lymphocytic leukemic L1210 cells, which contain exclusively PLD 2 . In addition, H 2 O 2 increased PLD activity only in PLD 2 ‐transfected COS‐7 cells and not in PLD 1 ‐transfected cells. This suggests that PLD 2 is selectively activated by H 2 O 2 . Depletion of extracellular Ca 2+ with EGTA completely blocked the H 2 O 2 ‐induced PLD activation, indicating that Ca 2+ influx is required. Moreover, pretreatment of the cells with the protein kinase C (PKC) inhibitors GF‐109203X and RO‐31‐8220 and down‐regulation of PKCct by prolonged treatment with 4β‐phorbol 12‐myristate 13‐acetate inhibited the H 2 O 2 ‐stimulated PLD 2 activity, which points to the involvement of PKCα. Based on these new findings we suggest that PLD 2 activity is specifically up‐regulated by H 2 O 2 and that the H 2 O 2 ‐induced PLD 2 activation is mediated by Ca 2+ influx and PKCα activation. J. Leukoc. Biol. 67: 630–636; 2000.