Parsing disease-relevant protein modifications from epiphenomena: perspective on the structural basis of SOD1-mediated ALS.
Parsing disease-relevant protein modifications from epiphenomena: perspective on the structural basis of SOD1-mediated ALS.
复制标题
DOI：
10.1002/jms.3953
复制
发表时间：
2017-07
期刊：
影响因子：
--
通讯作者：
Agar JN
中科院分区：
文献类型：
--
作者：
Schmitt ND;Agar JN
蛋白质的构象变化和修饰涉及许多细胞功能。然而，它们也可能产生与多种疾病有关的副作用。人们普遍不太清楚结构变化如何促进疾病。这一观点说明了质谱（MS）如何通过毒理学和流行病学验证来发现与疾病相关的结构变化和治疗策略。我们（与我们的合作者）着手表征细胞质抗氧化蛋白铜/锌超氧化物歧化酶 (SOD1) 的疾病相关突变和翻译后修饰 (PTM) 的结构和毒性后果。之前的遗传学研究发现 SOD1 基因中有超过 180 种不同的突变，这些突变导致家族性（遗传性）肌萎缩侧索硬化症 (fALS)。使用 HDX-MS，我们确定多种与疾病相关的 SOD1 突变会导致常见的结构缺陷 - SOD1 静电环的扰动。 X 射线晶体学研究表明，这通过静电环和暴露的 β 桶边缘链之间的特定相互作用导致蛋白质聚集。然后，我们使用流行病学方法确定 SOD1 稳定性降低和蛋白质聚集增加是 fALS 进展的强大危险因素，其综合风险比 > 300（作为比较，终生吸烟与肺癌的风险比约为 15）。由此产生的 fALS 病因结构模型支持以下假设：一些散发性 ALS（sALS，约 80% 的 ALS 与基因缺陷无关）可能是由野生型 SOD1 的翻译后蛋白修饰引起的。我们开发了免疫捕获抗体和高灵敏度自上而下 MS 方法，并使用人体组织样本表征了野生型 SOD1 的 PTM。然后，我们利用全局 HDX、X 射线晶体学和神经毒理学来表征 SOD1 PTM 的毒性和保护性子集。为了概括这一观点，我们提出了翻译后修饰可能导致疾病的概念验证。我们发现，许多突变（N→D；Q→E）会导致与 PTM 脱酰胺相同的化学结构，从而导致多种疾病。
Conformational change and modification of proteins are involved in many cellular functions. However, they can also have adverse effects that are implicated in numerous diseases. How structural change promotes disease is generally not well understood. This perspective illustrates how mass spectrometry (MS), followed by toxicological and epidemiological validation, can discover disease-relevant structural changes and therapeutic strategies. We (with our collaborators) set out to characterize the structural and toxic consequences of disease-associated mutations and post-translational modifications (PTMs) of the cytosolic antioxidant protein Cu/Zn-Superoxide dismutase (SOD1). Previous genetic studies discovered > 180 different mutations in the SOD1 gene that caused familial (inherited) amyotrophic lateral sclerosis (fALS). Using HDX-MS, we determined that diverse disease-associated SOD1 mutations cause a common structural defect – perturbation of the SOD1 electrostatic loop. X-ray crystallographic studies had demonstrated that this leads to protein aggregation through a specific interaction between the electrostatic loop and an exposed beta-barrel edge strand. Using epidemiology methods, we then determined that decreased SOD1 stability and increased protein aggregation are powerful risk factors for fALS progression, with a combined hazard ratio > 300 (for comparison, a lifetime of smoking is associated with a hazard ratio of ∼15 for lung cancer). The resulting structural model of fALS etiology supported the hypothesis that some sporadic ALS (sALS, ∼80% of ALS is not associated with a gene defect) could be caused by post-translational protein modification of wild-type SOD1. We developed immunocapture antibodies and high sensitivity top-down MS methods, and characterized PTMs of wild-type SOD1 using human tissue samples. Using global-HDX, X-ray crystallography, and neurotoxicology we then characterized toxic and protective subsets of SOD1 PTMs. To cap this perspective, we present proof-of-concept that post-translational modification can cause disease. We show that numerous mutations (N→D; Q→E), which result in the same chemical structure as the PTM deamidation, cause multiple diseases.
登录
查看更多内容
DOI：
10.1016/j.bbrc.2014.02.041
发表时间：
2014-03-21
影响因子：
3.1
作者：
Catherman, Adam D.;Skinner, Owen S.;Kelleher, Neil L.
通讯作者：
Kelleher, Neil L.
影响因子：
6
作者：
BRUCE, SE;BJARNASON, I;PETERS, TJ
通讯作者：
PETERS, TJ
影响因子：
3.9
作者：
Abel, Olubunmi;Powell, John F.;Al-Chalabi, Ammar
通讯作者：
Al-Chalabi, Ammar
影响因子：
12.7
作者：
Ayers JI;Fromholt SE;O'Neal VM;Diamond JH;Borchelt DR
通讯作者：
Borchelt DR
影响因子：
4.8
作者：
Coelho, Fernando R.;Iqbal, Asif;Augusto, Ohara
通讯作者：
Augusto, Ohara