Peptidylarginine deiminase modulates the physiological roles of enolase via citrullination: links between altered multifunction of enolase and neurodegenerative diseases
Peptidylarginine deiminase modulates the physiological roles of enolase via citrullination: links between altered multifunction of enolase and neurodegenerative diseases
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DOI：
10.1042/bj20120025
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发表时间：
2012-07-15
影响因子：
4.1
通讯作者：
Choi, Eun-Kyoung
中科院分区：
文献类型：
--
作者：
Jang, Byungki;Jeon, Yong-Chul;Choi, Eun-Kyoung
通过PAD（肽精氨酸脱亚胺酶）使烯醇化酶瓜氨酸化已成为人类疾病中重要的翻译后修饰；然而，瓜氨酸化的生理功能尚不清楚。在本研究中，我们报道瓜氨酸化不同地调节enol1 （α -烯醇化酶）和NSE（神经元特异性烯醇化酶）的生物学功能。我们开发了三种小鼠IgG1单克隆抗体，具有以下特异性：(1)ENO1的瓜氨酸化(9)[ENO1(Cit9)]；抗瓜氨酸烯醇化酶1 （ce2）抗体；（ii）在ENO1和NSE中Are的瓜氨酸化(ENO1(Cit9)/NSECit9；anti-CE1/2抗体);（iii） NSE的Arg（429）的瓜氨酸化（NSECit429；抗ce2抗体）。无论总蛋白表达水平如何，散发性克雅氏病和阿尔茨海默病患者的皮层神经元细胞或额叶皮层血管周围的ENO1（Cit9）和NSECit429水平均升高，其免疫反应活性也比对照组升高。PAD通过瓜氨酸化负向调节烯醇化酶活性，呈时间和剂量依赖性，患病患者的烯醇化酶活性比对照组更不活跃。有趣的是，烯醇化酶的瓜氨酸化有效地促进了Ca2+依赖性calpain-1的蛋白水解降解，而白细胞介素（calpain抑制剂1）则消除了这种降解。令人惊讶的是，通过亲和力测定，烯醇化酶的瓜氨酸化增强了它与纤溶酶原结合的亲和力，而这种亲和力被赖氨酸类似物epsiln -氨基己酸阻断。这些发现表明，pad介导的瓜氨酸化调节了烯醇化酶的多种生理活性，CE可能是退行性疾病的候选诊断/预后因素。
The citrullination of enolase by PAD (peptidylarginine deiminase) has emerged as an important post-translational modification in human disorders; however, the physiological function of citrullination remains unknown. In the present study, we report that citrullination diversely regulates the biological functions of ENO1 (alpha-enolase) and NSE (neuron-specific enolase). We developed three mouse IgG1 monoclonal antibodies with specificity to the following: (i) citrullination of Are(9) of ENO1 [ENO1(Cit9); anti-CE2 (citrullinated enolase 1) antibody]; (ii) citrullination of Are in ENO1 and NSE (ENO1(Cit9)/NSECit9; anti-CE1/2 antibody); and (iii) citrullination of Arg(429) of NSE (NSECit429; anti-CE2 antibody). Regardless of the total protein expression level, the levels of ENO1(Cit9) and NSECit429 were elevated, and their immunoreactivities were also increased in cortical neuronal cells or around blood vessels in the frontal cortex of patients with sporadic Creutzfeldt-Jakob disease and Alzheimer's disease compared with controls. In a time- and dose-dependent manner, PAD negatively regulated enolase activity via citrullination, and enolase in diseased patients was more inactive than in controls. Interestingly, the citrullination of enolase effectively promoted its proteolytic degradation by Ca2+-dependent calpain-1, and leupeptin (calpain inhibitor 1) abrogated this degradation. Surprisingly, using an affinity assay, the citrullination of enolase enhanced its plasminogen-binding affinity, which was blocked by the lysine analogue epsilon-aminocaproic acid. These findings suggest that PAD-mediated citrullination regulates the diverse physiological activities of enolase and that CE may be a candidate diagnostic/prognostic factor for degenerative diseases.