Quantitative Phosphoproteomic Analysis in Alpha-Synuclein Transgenic Mice Reveals the Involvement of Aberrant p25/Cdk5 Signaling in Early-stage Parkinson's Disease
Quantitative Phosphoproteomic Analysis in Alpha-Synuclein Transgenic Mice Reveals the Involvement of Aberrant p25/Cdk5 Signaling in Early-stage Parkinson's Disease
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α-突触核蛋白转基因小鼠的定量磷酸化蛋白质组分析揭示了异常 p25/Cdk5 信号传导与早期帕金森病的关系
DOI：
10.1007/s10571-019-00780-7
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发表时间：
2020-02-03
影响因子：
4
通讯作者：
Zhang, Pei
中科院分区：
文献类型：
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作者：
He, Feng;Qi, Guangjian;Zhang, Pei
编码突触前蛋白α-突触核蛋白的基因A30P和A53T突变是帕金森病(PD)最常见的遗传原因。α-突触核蛋白的异常可能在帕金森病患者的多巴胺能神经元死亡和运动症状中起核心作用。本研究通过对6个月龄α-突触核蛋白转基因小鼠(A30P/A53T双突变人α-突触核蛋白；hM(2)α-SYN-39株)黑质致密部(SNPC)组织样本的磷酸化蛋白质组学分析，研究了早期帕金森病患者的蛋白质磷酸化特征。我们鉴定了2136个磷酸蛋白中的5351个磷酸化位点。其中，245种蛋白质中的357个上调位点和46种蛋白质中的50个下调位点在α-突触核蛋白转基因小鼠和野生型小鼠之间存在差异磷酸化。生物信息学分析，包括基因本体论，京都百科全书的基因和基因组途径丰富，以及Motif分析，以阐明双突变人α-突触核蛋白过表达的分子和细胞机制。基于SCANSITE的计算分析和对差异定量的磷蛋白的预测表明，神经元蛋白细胞周期蛋白依赖性激酶5(CDK5)是最显著的浓缩蛋白。生化实验表明，在MPP+诱导的细胞培养模型和MPTP诱导的小鼠模型中，p25/CDK5通路被激活。此外，在体外，CDK5可以直接磷酸化位于Ser1889的Ank2蛋白。因此，使用α-突触核蛋白转基因小鼠模型的定量磷酸蛋白质组学为阐明帕金森病动物模型中SNPC多巴胺能神经元死亡的蛋白磷酸化机制提供了有力的途径。
A30P and A53T mutations in the gene encoding alpha-synuclein-a presynaptic protein-are the most frequently identified genetic causes of Parkinson's disease (PD). Aberrant alpha-synuclein likely plays central roles in dopaminergic neuronal death and motor symptoms in PD. This study investigated the protein phosphorylation profile in early-stage PD through phosphoproteomic analyses of tissue samples from the substantia nigra pars compacta (SNpc) of 6-month-old alpha-synuclein transgenic mice (A30P/A53T double-mutant human alpha-synuclein; hm(2)alpha-SYN-39 strain). We identified 5351 phosphorylation sites in 2136 phosphoproteins. Of these, 357 upregulated sites in 245 proteins and 50 downregulated sites in 46 proteins were differentially phosphorylated between alpha-synuclein transgenic and wildtype mice. Bioinformatic analyses, including Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway enrichment, and motif analyses, were used to elucidate the molecular and cellular mechanisms underlying double-mutant human alpha-synuclein overexpression. Scansite-based computational analysis and prediction of differentially quantitated phosphoproteins identified the neuronal protein cyclin-dependent kinase 5 (Cdk5) as the most significantly enriched kinase. Biochemical experiments suggested that the p25/Cdk5 pathway was activated in an MPP+-induced cell culture model and MPTP-induced mouse model. Moreover, Cdk5 could directly phosphorylate the Ank2 protein at Ser1889 in vitro. Therefore, quantitative phosphoproteomic using an alpha-synuclein transgenic mouse model offers a powerful approach for elucidating the protein phosphorylation mechanism underlying SNpc dopaminergic neuronal death in an animal model of PD.