IDENTIFICATION AND CHARACTERIZATION OF A NOVEL UBIQUITIN LIGASE SIAH THAT EXHIBITS COMPLEMENTARY ROLES WITH PARKIN

与 Parkin 发挥互补作用的新型泛素连接酶 SIAH 的鉴定和表征

• 批准号: 15590893
• 负责人: YAMASHITA Hiroshi
• 金额: $ 2.24万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15590893/
• 关键词: Parkinson's disease; Parkin; α-synuclein; SIAH; Synphilin-1; ubiquitination; ubiquitin lipase; Lewy body; α-Synuclein; Synphilin-1; Siah-1; ユビキチン; ドーパミン

Parkinson's disease is a common neurodegenerative disorder characterized by loss of dopaminergic neurons and appearance of Lewy bodies, cytoplasmic inclusions that are highly enriched with ubiquitin. Synphilin-1, α-synuclein and Parkin represent the major components of Lewy bodies, and are involved in pathogenesis of Parkinson's disease. Synphilin-1 is anα-synuclein binding protein that is ubiquitinated by Parkin. Recently, a mutation in the synphilin-1 gene is reported in patients with sporadic Parkinson's disease. Although synphilin-1 localizes close to synaptic vesicles, its function remains unknown. To investigate the proteins that interact with synphilin-1, the present study performed a yeast two-hybrid screening and identified a novel interacting protein, Siah-1 ubiquitin ligase. Synphilin-1 and Siah-1 proteins were endogenously expressed in the central nervous system, and coimmunoprecipitated each other in rat brain homogenate. Confocal microscopic analysis revealed colocalization of both proteins in cells. Siah-1 was found to interact with the N-terminus of synphilin-1 through its substrate-binding domain, and specifically ubiquitinate synphilin-1 via its RING finger domain. Siah-1 facilitated synphilin-1 degradation via the ubiquitin-proteasome pathway more efficiently than Parkin. Siah-1 was found not to facilitate ubiquitination and degradation of wild type or mutant α-synuclein. Synphilin-1 inhibited high K^+-induced dopamine release from PC12 cells. Siah-1 was found to abrogate the inhibitory effect of synphilin-1 on dopamine release. Such findings suggest that Siah-1 might play a role in regulation of synphilin-1 function.

帕金森病是一种常见的神经退行性疾病，其特征是多巴胺能神经元的丧失和路易小体的出现，路易小体是富含泛素的细胞质包涵体。Synphilin-1、α-突触核蛋白和Parkin是路易小体的主要成分，参与帕金森病的发病。Synphilin-1是一种α-突触核蛋白结合蛋白，被Parkin泛素化。最近，在散发性帕金森病患者中报道了一种突触蛋白-1基因突变。虽然synphilin-1定位于突触囊泡附近，但其功能尚不清楚。为了研究与synphilin-1相互作用的蛋白，本研究进行了酵母双杂交筛选，并鉴定了一种新的相互作用蛋白Siah-1泛素连接酶。Synphilin-1和Siah-1蛋白在中枢神经系统内源性表达，并在大鼠脑匀浆中相互共免疫沉淀。共聚焦显微镜分析显示这两种蛋白在细胞中的共定位。发现Siah-1通过底物结合域与synphilin-1的n端相互作用，并通过其环指结构域特异性地泛素化synphilin-1。Siah-1通过泛素-蛋白酶体途径比Parkin更有效地促进synphilin-1的降解。发现Siah-1不促进野生型或突变型α-突触核蛋白的泛素化和降解。Synphilin-1抑制高K^+诱导的PC12细胞多巴胺释放。发现Siah-1能消除synphilin-1对多巴胺释放的抑制作用。这些发现提示Siah-1可能在synphilin-1的功能调控中起作用。

项目成果

Identification and characterization of a novel Pyk2/Related adhesion focal tyrosine kinase-associated protein that inhibits α-synuclein phosphorylation

抑制 α-突触核蛋白磷酸化的新型 Pyk2/Related 粘附局灶酪氨酸激酶相关蛋白的鉴定和表征

• 发表时间: 2003
• 期刊: Journal of Biological Chemistry 278
• 作者: Yamashita H;et al.;Nagano Y et al.;Takahashi T et al.
• 通讯作者: Takahashi T et al.

パーキンソン病の病態解明

阐明帕金森病的病理学

• 发表时间: 2004
• 期刊: 日本臨床 62
• 作者: 山下 拓史

Elucidation of the pathogenesis of Parkinson's disease

阐明帕金森病的发病机制

• 发表时间: 2004
• 期刊: Nippon Rinsho 62
• 作者: Yamashita H;et al.
• 通讯作者: et al.

Siah-1 facilitates ubiquitination and degradation of synphilin-1

• DOI: 10.1074/jbc.m306347200
• 发表时间: 2003-12-19
• 期刊: JOURNAL OF BIOLOGICAL CHEMISTRY
• 影响因子: 4.8
• 作者: Nagano, Y;Yamashita, H;Matsumoto, M
• 通讯作者: Matsumoto, M

Identification and characterization of a novel Pyk2/related adhesion focal tyrosine kinase-associated protein that inhibits alpha-synuclein phosphorylation

抑制 α-突触核蛋白磷酸化的新型 Pyk2/相关粘附局灶酪氨酸激酶相关蛋白的鉴定和表征

• 发表时间: 2003
• 期刊: J Biol Chem 278
• 作者: Takahashi T;et al.
• 通讯作者: et al.