Identification of novel cytosolic phospholipase A2s, murine cPLA2δ, ε, and ζ, which form a gene cluster with cPLA2β
Identification of novel cytosolic phospholipase A2s, murine cPLA2δ, ε, and ζ, which form a gene cluster with cPLA2β
复制标题
DOI：
10.1074/jbc.m413711200
复制
发表时间：
2005-07-01
影响因子：
4.8
通讯作者：
Shimizu, T
中科院分区：
文献类型：
--
作者：
Ohto, T;Uozumi, N;Shimizu, T
磷脂酶A（2）水解甘油磷脂的sn-2酯键，产生游离脂肪酸和溶血磷脂。胞浆磷脂酶A（2）s（cPLA（2），IV组）是作用于细胞内磷脂膜的酶的亚组。研究最充分的cPLA（2）α（IVA组）是体内脂质介质产生的关键酶。在这里，我们报告了新的小鼠cPLA（2）s的克隆和表征：cPLA（2）delta（IVD组），cPLA（2）delta（IVE组）和cPLA（2）zeta（IVF组），它们与cPLA（2）beta（IVB组）形成基因簇。推导的cPLA（2）delta、delta和zeta氨基酸序列表明cPLA（2）具有保守的结构域结构，即：e.一个C2结构域和一个脂肪酶结构域。这些新克隆的cPLA 2的潜在催化二联体Ser和Asp是保守的，沿着周围残基具有相对高的保守性。小鼠cPLA（2）delta、cPLA（2）zeta和cPLA（2）delta的转录物似乎在某些器官中富集，而不是普遍分布。在胎盘中检测到cPLA（2）δ的主要北方信号，在甲状腺、心脏和骨骼肌中检测到cPLA（2）δ，在甲状腺中检测到cPLA（2）zeta。在人胚肾293细胞中表达的重组蛋白经Western印迹证实分子大小约为100 kDa，并显示对1-棕榈酰-2-[C-14]花生四烯酸-磷脂酰胆碱底物的Ca 2+依赖性PLA（2）活性。与cPLA（2）alpha相比，cPLA（2）zeta更喜欢磷脂酰乙醇胺而不是磷脂酰胆碱。通过绿色荧光标记的蛋白质可视化细胞内定位。每种分子都显示出特异性定位，cPLA（2）δ在钙离子载体刺激下从胞浆转移到核周区域。因此，我们发现了这些功能新颖的cPLA 2基因，其聚集在小鼠染色体2 E5上。
Phospholipase A(2) hydrolyzes the sn-2 ester bond of glycerophospholipids that produce free fatty acids and lysophospholipids. Cytosolic phospholipase A(2)s ( cPLA(2), group IV) are a subgroup of enzymes that act on the intracellular phospholipid membrane. The best investigated cPLA(2)alpha( group IVA) is a key enzyme for lipid mediator production in vivo. Here we report cloning and characterization of novel murine cPLA(2)s: cPLA(2)delta ( group IVD), cPLA(2)epsilon ( group IVE), and cPLA(2)zeta ( group IVF), that form a gene cluster with cPLA(2)beta ( group IVB). The deduced amino acid sequences of cPLA(2)delta, epsilon, and zeta demonstrated a conserved domain structure of cPLA(2), i. e. one C2 domain and one lipase domain. The potential catalytic dyad, Ser and Asp, was conserved for these newly cloned cPLA2s along with relatively high conservation for the surrounding residues. Transcripts of murine cPLA(2)delta, epsilon, and zeta appeared to be enriched in certain organs rather than ubiquitous distribution. Major Northern signals for cPLA(2)delta were detected in placenta, cPLA(2)epsilon in thyroid, heart, and skeletal muscle, and cPLA(2)zeta in thyroid. Recombinant proteins expressed in human embryonic kidney 293 cells demonstrated molecular sizes of about 100 kDa by Western blotting and exhibited Ca2+-dependent PLA(2) activities on 1-palmitoyl-2-[C-14] arachidonoyl-phosphatidylcholine substrate. In contrast to cPLA(2)alpha, cPLA(2)zeta preferred phosphatidylethanolamine to phosphatidylcholine. Intracellular localization was visualized by green fluorescent-tagged proteins. Each molecule showed specific localization, and cPLA(2)delta translocated from the cytosol to the perinuclear region by calcium-ionophore stimulation. We thus discovered these functional novel cPLA2 genes, which cluster on murine chromosome 2E5.