Cloning of a unique lipase from endothelial cells extends the lipase gene family
Cloning of a unique lipase from endothelial cells extends the lipase gene family
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DOI：
10.1074/jbc.274.20.14170
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发表时间：
1999-05-14
影响因子：
4.8
通讯作者：
Quertermous, T
中科院分区：
文献类型：
--
作者：
Hirata, K;Dichek, HL;Quertermous, T
通过差减方法从内皮细胞中克隆了一个新的脂蛋白脂酶样基因，旨在鉴定该细胞在体外分化过程中表达的基因。内皮细胞来源的脂肪酶蛋白含有500个氨基酸，包括一个18个氨基酸的疏水信号序列，与脂蛋白脂肪酶有44%的同源性，与肝脂肪酶有41%的同源性。与脂蛋白和肝脂酶的一级序列比较表明，丝氨酸、天冬氨酸和组氨酸催化残基以及参与二硫键形成的10个半胱氨酸残基是保守的。Northern印迹法检测到培养的人脐静脉内皮细胞、人冠状动脉内皮细胞和小鼠内皮样卵黄囊细胞均有表达。此外，Northern印迹和原位杂交分析显示内皮源性脂肪酶在胎盘、肝脏、肺、卵巢、甲状腺和睾丸中有表达。转基因COS7细胞分泌的c-Myc标记蛋白具有磷脂酶A1活性，但不具有甘油三酯脂肪酶活性。它的组织限制性表达模式和由内皮细胞表达的能力表明，内皮细胞衍生脂肪酶在脂蛋白代谢和血管疾病中可能具有独特的功能。
A new lipoprotein lipase-like gene has been cloned from endothelial cells through a subtraction methodology aimed at characterizing genes that are expressed with in vitro differentiation of this cell type. The conceptual endothelial cell-derived lipase protein contains 500 amino acids, including an 18-amino acid hydrophobic signal sequence, and is 44% identical to lipoprotein lipase and 41% identical to hepatic lipase. Comparison of primary sequence to that of lipoprotein and hepatic lipase reveals conservation of the serine, aspartic acid, and histidine catalytic residues as well as the 10 cysteine residues involved in disulfide bond formation. Expression was identified in cultured human umbilical vein endothelial cells, human coronary artery endothelial cells, and murine endothelial-like yolk sac cells by Northern blot. In addition, Northern blot and in situ hybridization analysis revealed expression of the endothelial-derived lipase in placenta, liver, lung, ovary, thyroid gland, and testis. A c-Myc-tagged protein secreted from transfected COS7 cells had phospholipase Al activity but no triglyceride lipase activity. Its tissue-restricted pattern of expression and its ability to be expressed by endothelial cells, suggests that endothelial cell-derived lipase may have unique functions in lipoprotein metabolism and in vascular disease.