Phospholipase D

Exton, John H.

doi:10.1016/s0005-2760(98)00124-6

Cited by 113 publications

(91 citation statements)

References 103 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, in several cell systems it has been shown that activation of PLC and PLD is modulated by the EGF receptor and that some types of PKC may control PLD activity (Exton, 1998;Wahl and Carpenter, 1988;Kaszkin et al, 1992;Yeo and Exton, 1995). Further, an increase in the activity of lipid-dependent PKC-isoenzymes in E5-expressing cells has been observed (Straight et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

“…Also interesting is the fact that E5-expression is accompanied by an increased translocation of phorbol 12-myristate 13-acetate (PMA)-dependent PKC subtypes to the cellular membranes (Crusius et al, , 1998. Transcription/translation of the E5 reading frame in the presence of microsomal membranes results in the incorporation of the protein into the added membranes (Faulkner-Valle and Banks, 1995;Faccini et al, 1996). Thus many of the functions of E5 may be due to its localization in cellular membranes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The human papillomavirus type 16 E5 protein modulates phospholipase C-γ-1 activity and phosphatidyl inositol turnover in mouse fibroblasts

et al. 1999

View full text Add to dashboard Cite

The human papillomavirus type 16 E5 (HPV16-E5) protein is a membrane protein that has been associated with malignant growth. The protein aects growth factor-mediated signal transduction in a ligand-dependent manner. We show now that E5 expression in A31 ®broblasts results in an increased level of diacylglycerol (DAG) and inositol phosphates. Immunoprecipitation of phospholipase C-g-1 (PLC-g-1) with speci®c antibodies and immunoblotting with anti-phosphotyrosine antibodies reveal a large increase in tyrosine phosphorylation of the enzyme in E5-expressing cells compared to control vector-transfected cells. This activation of tyrosine phosphorylation is growth factor independent. In addition, an enhanced formation of phosphatidic acid (PA) was observed in E5 cells. This increase did not result from activation of phospholipase D (PLD), although the enzyme was activatable by treatment with phorbol ester. Thus, a phosphohydrolase-mediated DAG synthesis from PLD-produced PA can be excluded. The observed eects were not further enhanced by EGF showing that the presence of the growth factor is not necessary for maintaining permanent activation of PLC-g-1 in E5-expressing cells. The DAG-and inositol phosphatemediated signal cascade within the cells is thus eectively uncoupled from external control via EGF and its receptor in the presence of E5 protein.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The human papillomavirus type 16 E5 protein modulates phospholipase C-γ-1 activity and phosphatidyl inositol turnover in mouse fibroblasts

et al. 1999

View full text Add to dashboard Cite

show abstract

“…PMA has been shown to stimulate PtdEtn synthesis in freshly isolated hepatocytes [37] and to increase intracellular DAG levels via activation of the phospholipase D-catalysed hydrolysis of PtdCho and PtdEtn in combination with phosphatidate phosphohydrolase [38]. On the other hand, treatment of cells with PLC has been shown to increase intracellular DAG levels and stimulate PtdCho synthesis in several cell lines [35,39,40].…”

Section: Stable Overexpression Of Rat Liver Ect In Cultured Rat Hepatmentioning

confidence: 99%

Control of the CDPethanolamine pathway in mammalian cells: effect of CTP:phosphoethanolamine cytidylyltransferase overexpression and the amount of intracellular diacylglycerol

Bleijerveld

Klein

Vaandrager

et al. 2004

Biochemical Journal

View full text Add to dashboard Cite

For an insight regarding the control of PtdEtn (phosphatidylethanolamine) synthesis via the CDPethanolamine pathway, rat liver cDNA encoding ECT (CTP:phosphoethanolamine cytidylyltransferase) was transiently or stably transfected in Chinesehamster ovary cells and a rat liver-derived cell line (McA-RH7777), resulting in a maximum of 26-and 4-fold increase in specific activity of ECT respectively. However, no effect of ECT overexpression on the rate of [ 3 H]ethanolamine incorporation into PtdEtn was detected in both cell lines. This was explored further in cells overexpressing four times ECT activity (McA-ECT1). The rate of PtdEtn breakdown and PtdEtn mass were not changed in McA-ECT1 cells in comparison with controltransfected cells. Instead, an accumulation of CDPethanolamine (label and mass) was observed, suggesting that in McA-ECT1 cells the ethanolaminephosphotransferase-catalysed reaction became rate-limiting. However, overexpression of the human choline/ethanolaminephosphotransferase in McA-ECT1 and control-transfected cells had no effect on PtdEtn synthesis. To investigate whether the availability of DAG (diacylglycerol) limited PtdEtn synthesis in these cells, intracellular DAG levels were increased using PMA or phospholipase C. Exposure of cells to PMA or phospholipase C stimulated PtdEtn synthesis and this effect was much more pronounced in McA-ECT1 than in controltransfected cells. In line with this, the DAG produced after PMA exposure was consumed more rapidly in McA-ECT1 cells and the CDPethanolamine level decreased accordingly. In conclusion, our results suggest that the supply of CDPethanolamine, via the expression level of ECT, is an important factor governing the rate of PtdEtn biosynthesis in mammalian cells, under the condition that the amount of DAG is not limiting.

show abstract

“…Phospholipase D (PLD) catalyses the hydrolysis of phosphatidylcholine to generate phosphatidic acid (PA), a second messenger, and choline (Exton, 1998;Cockcroft, 2001). Two main products of PLD genes have been described: PLD1 and PLD2 Park et al, 1997;Lopez et al, 1998;Sung et al, 1999), as well as their regulators (Powner and Wakelam, 2002).…”

Section: Introductionmentioning

confidence: 99%