Key Laboratory of Molecular Biology, College of Bio-information, Chongqing University of Posts and Telecommunications, Nan'an District, 400065 Chongqing, People's Republic of China.
Mol Cell Biochem. 2010 Jun;339(1-2):181-90. doi: 10.1007/s11010-009-0382-0. Epub 2010 Jan 8.
A mammalian family of lipid hydrolases, designated "patatin-like phospholipase domain containing (PNPLA)" recently has attracted attention. NTE-related esterase (NRE) as a member of PNPLA is an insulin-regulated lysophospholipase with homology to neuropathy target esterase (NTE). Mouse NRE (mNRE) has a predicted amino-terminal transmembrane region (TM), a putative regulatory (R) domain, and a hydrophobic catalytic (C) domain. In the current study, we described the expression of green fluorescent protein (GFP)-tagged constructs of mNRE and mutant proteins lacking the specific protein domains. Esterase assays indicated that neither the TM nor R-domain was essential for mNRE esterase activity, but the TM significantly contributed to its activity. Subcellular distribution showed that mNRE was anchored in ER via its TM domain and that its C-domain was associated with ER. Furthermore, experiments involving proteinase treatment revealed that most of mNRE molecule was exposed on the cytoplasmic face of ER membranes. Collectively, our results for the first time revealed the protein domains, catalytic activity, and subcellular location of mNRE and a simplified model for mNRE was proposed.
最近，人们关注到一个哺乳动物脂质水解酶家族，被命名为“含有 patatin 样磷脂酶结构域（PNPLA）”。NTE 相关酯酶（NRE）作为 PNPLA 的一个成员，是一种胰岛素调节的溶血磷脂酶，与神经病靶酯酶（NTE）具有同源性。小鼠 NRE（mNRE）具有预测的氨基末端跨膜区（TM）、假定的调节（R）结构域和疏水性催化（C）结构域。在本研究中，我们描述了 GFP 标记的 mNRE 和缺失特定蛋白结构域的突变蛋白的构建体的表达。酯酶测定表明，TM 结构域和 R 结构域都不是 mNRE 酯酶活性所必需的，但 TM 结构域对其活性有显著贡献。亚细胞分布表明，mNRE 通过其 TM 结构域锚定在 ER 上，其 C 结构域与 ER 相关联。此外，涉及蛋白酶处理的实验表明，mNRE 的大部分分子暴露在 ER 膜的细胞质侧。总之，我们的结果首次揭示了 mNRE 的蛋白结构域、催化活性和亚细胞定位，并提出了 mNRE 的简化模型。
