Specific inhibition of rat brain phospholipase D by lysophospholipids
Although the importance of phospholipase D (PLD) in signal transduction in mammalian cells is well documented, the negative regulation of PLD is poorly understood. This is primarily due to a lack of known specific inhibitors of PLD. We herein report that the activity of partially purified rat brain...
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| Format: | Article |
| Language: | English |
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Elsevier
2000-06-01
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| Series: | Journal of Lipid Research |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520320368 |
| _version_ | 1818671451536883712 |
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| author | Stephen B. Ryu Jiwan P. Palta |
| author_facet | Stephen B. Ryu Jiwan P. Palta |
| author_sort | Stephen B. Ryu |
| collection | DOAJ |
| description | Although the importance of phospholipase D (PLD) in signal transduction in mammalian cells is well documented, the negative regulation of PLD is poorly understood. This is primarily due to a lack of known specific inhibitors of PLD. We herein report that the activity of partially purified rat brain PLD is inhibited by certain lysophospholipids, such as lysophosphatidylinositol, lysophosphatidylglycerol, and lysophosphatidylserine in a highly specific manner. Inhibition of PLD by lysophospholipids was dose-dependent: the concentration of lysophosphatidylinositol required for half-maximal inhibition was about 3 μm. An analysis of the enzyme-kinetics suggested that lysophospholipids act as non-competitive inhibitors of PLD activity. As expected, PLD activity was stimulated by ADP-ribosylation factor (Arf) and phosphatidylinositol 4,5-bisphosphate (PIP2). The inhibition of PLD by lysophospholipids, however, was not affected by the presence or absence of Arf or by an increase in PIP2 concentration. A protein-binding assay suggested that lysophospholipids bind directly to PLD. These results indicate that the observed inhibition of PLD by lysophospholipids is due to their direct interaction rather than to an interaction between lysophospholipids and either Arf or PIP2.The present study suggests that certain lysophospholipids are specific inhibitors of rat brain PLD in a cell-free system and may provide the new opportunities to investigate mechanisms by which PLD is regulated by lysophospholipids, presumably liberated by phospholipase A2 activation, in mammalian cells. |
| first_indexed | 2024-12-17T07:24:13Z |
| format | Article |
| id | doaj.art-f8408919a18a48a0bb34ab337ed729c3 |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-17T07:24:13Z |
| publishDate | 2000-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-f8408919a18a48a0bb34ab337ed729c32022-12-21T21:58:40ZengElsevierJournal of Lipid Research0022-22752000-06-01416940944Specific inhibition of rat brain phospholipase D by lysophospholipidsStephen B. Ryu0Jiwan P. Palta1Department of Horticulture, University of Wisconsin–Madison, Madison, WI 53706To whom correspondence should be addressed.; Department of Horticulture, University of Wisconsin–Madison, Madison, WI 53706Although the importance of phospholipase D (PLD) in signal transduction in mammalian cells is well documented, the negative regulation of PLD is poorly understood. This is primarily due to a lack of known specific inhibitors of PLD. We herein report that the activity of partially purified rat brain PLD is inhibited by certain lysophospholipids, such as lysophosphatidylinositol, lysophosphatidylglycerol, and lysophosphatidylserine in a highly specific manner. Inhibition of PLD by lysophospholipids was dose-dependent: the concentration of lysophosphatidylinositol required for half-maximal inhibition was about 3 μm. An analysis of the enzyme-kinetics suggested that lysophospholipids act as non-competitive inhibitors of PLD activity. As expected, PLD activity was stimulated by ADP-ribosylation factor (Arf) and phosphatidylinositol 4,5-bisphosphate (PIP2). The inhibition of PLD by lysophospholipids, however, was not affected by the presence or absence of Arf or by an increase in PIP2 concentration. A protein-binding assay suggested that lysophospholipids bind directly to PLD. These results indicate that the observed inhibition of PLD by lysophospholipids is due to their direct interaction rather than to an interaction between lysophospholipids and either Arf or PIP2.The present study suggests that certain lysophospholipids are specific inhibitors of rat brain PLD in a cell-free system and may provide the new opportunities to investigate mechanisms by which PLD is regulated by lysophospholipids, presumably liberated by phospholipase A2 activation, in mammalian cells.http://www.sciencedirect.com/science/article/pii/S0022227520320368bioactive phospholipidsPLD regulationphospholipase A2LPELPILPS |
| spellingShingle | Stephen B. Ryu Jiwan P. Palta Specific inhibition of rat brain phospholipase D by lysophospholipids Journal of Lipid Research bioactive phospholipids PLD regulation phospholipase A2 LPE LPI LPS |
| title | Specific inhibition of rat brain phospholipase D by lysophospholipids |
| title_full | Specific inhibition of rat brain phospholipase D by lysophospholipids |
| title_fullStr | Specific inhibition of rat brain phospholipase D by lysophospholipids |
| title_full_unstemmed | Specific inhibition of rat brain phospholipase D by lysophospholipids |
| title_short | Specific inhibition of rat brain phospholipase D by lysophospholipids |
| title_sort | specific inhibition of rat brain phospholipase d by lysophospholipids |
| topic | bioactive phospholipids PLD regulation phospholipase A2 LPE LPI LPS |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520320368 |
| work_keys_str_mv | AT stephenbryu specificinhibitionofratbrainphospholipasedbylysophospholipids AT jiwanppalta specificinhibitionofratbrainphospholipasedbylysophospholipids |