Human Group IVC Phospholipase A2(cPLA2γ)
| Autor: | Naonori Uozumi, Kenji Asai, Toshiaki Houjou, Ryo Taguchi, Takao Shimizu, Tetsuya Hirabayashi |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Phosphatidylethanolamine
biology Endoplasmic reticulum Phospholipid Tyrosine phosphorylation Cell Biology Golgi apparatus Biochemistry Cell biology Enzyme activator chemistry.chemical_compound symbols.namesake Phospholipase A2 chemistry biology.protein symbols lipids (amino acids peptides and proteins) Arachidonic acid Molecular Biology |
| Zdroj: | Journal of Biological Chemistry. 278:8809-8814 |
| ISSN: | 0021-9258 |
| Popis: | To create the unique properties of a certain cellular membrane, both the composition and the metabolism of membrane phospholipids are key factors. Phospholipase A2(PLA2), with hydrolytic enzyme activities at thesn-2 position in glycerophospholipids, plays critical roles in maintaining the phospholipid composition as well as producing bioactive lipid mediators. In this study we examined the contribution of a Ca2+-independent group IVC PLA2 isozyme (cPLA2γ), a paralogue of cytosolic PLA2α (cPLA2α), to phospholipid remodeling. The enzyme was localized in the endoplasmic reticulum and Golgi apparatus, as seen using green fluorescence fusion proteins. Electrospray ionization mass spectrometric analysis of membrane extracts revealed that overexpression of cPLA2γ increased the proportion of polyunsaturated fatty acids in phosphatidylethanolamine, suggesting that the enzyme modulates the phospholipid composition. We also found that H2O2 and other hydroperoxides induced arachidonic acid release in cPLA2γ-transfected human embryonic kidney 293 cells, possibly through the tyrosine phosphorylation pathway. Thus, we propose that cPLA2γ is constitutively expressed in the endoplasmic reticulum and plays important roles in remodeling and maintaining membrane phospholipids under various conditions, including oxidative stress. |
| Databáze: | OpenAIRE |
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