Selectively increased oxidative modifications mapped to detergent-insoluble forms of Aβ and β-III tubulin in Alzheimer's disease
Selectively increased oxidative modifications mapped to detergent-insoluble forms of Aβ and β-III tubulin in Alzheimer's disease
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DOI：
10.1096/fj.06-5920com
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发表时间：
2006-07-01
期刊：
影响因子：
4.8
通讯作者：
Montine, Thomas J.
中科院分区：
文献类型：
--
作者：
Boutte, Angela M.;Woltjer, Randall L.;Montine, Thomas J.
神经元细胞骨架的有害翻译后修饰（PTMs）是阿尔茨海默病（AD）中淀粉样蛋白(a) β肽积累与随后的tau异常和神经退行性变之间的机制联系。在这里，我们测试了神经元小管上的ptm选择性地积聚在AD的病理蛋白部分的假设。我们使用新的软件P-MOD，利用来自AD的可溶性（正常）和清洁剂不溶性（病理）蛋白质部分的质谱数据，以及来自对照组的总提取物，对选定的蛋白质进行全面鉴定和绘制ptm，这些蛋白质包括：A β、tau、载脂蛋白（apo） E、胶质纤维酸性蛋白（GFAP）、α - iii微管蛋白和β - iii微管蛋白。我们的结果证实了其他人的直接观察，在AD的洗涤剂不溶性蛋白的A β位置35和tau磷酸化的许多位点上鉴定了蛋氨酸(M)亚硫化物，而在该部分中，主要星形胶质细胞衍生的apoE或GFAP上没有ptm富集。P-MOD将几种丰富的M亚砜映射到富含神经元的α - iii微管蛋白上，但没有映射到其异二聚体伙伴-富含神经元的α - iii微管蛋白上，这一结果通过选择性抑制cnbr介导的α - iii微管蛋白的裂解得到证实。这些发现是对阿尔茨海默病中PTMs的首次全面评估，并指出β - iii微管蛋白的氧化修饰是阿尔茨海默病特征的神经元细胞骨架破坏的潜在因素。
Deleterious post-translational modifications (PTMs)to the neuronal cytoskeleton are a proposed mechanistic link between accumulation of amyloid (A) beta peptides and subsequent abnormalities of tau and neurodegeneration in Alzheimer's disease (AD). Here we tested the hypothesis that PTMs on neuronal tubulins selectively accumulate in a pathological protein fraction in AD. We used new software, P-MOD, to identify comprehensively and map PTMs using mass spectral data from soluble (normal) and detergent-insoluble (pathological) protein fractions from AD, as well as total extracts from controls, for selected proteins: A beta, tau, apolipoprotein (apo) E, glial fibrillary acidic protein (GFAP), alpha-III tubulin, and beta-III tubulin. Our results confirmed direct observations of others by identifying methionine (M) sulfoxides at A beta position 35 and numerous sites of tau phosphorylation in detergent-insoluble protein from AD, while no PTMs were enriched on primarily astrocyte-derived apoE or GFAP in this fraction. P-MOD mapped several abundant M sulfoxides to neuron-enriched alpha-III tubulin but not its heterodimeric partner, neuron-enriched alpha-III tubulin, a result confirmed by selective suppression of CNBr-mediated cleavage of alpha-III tubulin. These findings are the first comprehensive assessment of PTMs in AD and point to oxidative modification of beta-III tubulin as a potential contributor to the neuronal cytoskeletal disruption that is characteristic of AD.