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研究揭示病理性TDP-43丝的结构
作者:小柯机器人 发布时间:2021/12/11 21:47:00

英国MRC分子生物学实验室Benjamin Ryskeldi-Falcon课题组揭示来自具有额颞叶退化(FTLD)的肌萎缩侧索硬化症(ALS)患者的病理性TDP-43丝结构。2021年12月8日,国际知名学术期刊《自然》在线发表了这一成果。

研究人员表示,TAR DNA结合蛋白43 kDa(TDP-43)在神经元和胶质中的异常聚集是神经退行性疾病和多种形式的FTLD的决定性病理标志。它在其他疾病中也很常见,包括阿尔茨海默氏症和帕金森症。这些疾病没有改变病情的治疗方法,早期诊断也不可能。病理性TDP-43聚集物的结构是未知的。
 
在一个患有ALS并伴有FTLD患者的额叶和运动皮层中以及第二个具有相同诊断患者的额叶皮层中,研究人员利用冷冻电镜确定了聚集的TDP-43结构。在这两个脑区和个人中都发现了一个由单一原丝组成的相同淀粉样细丝结构。有序的丝状核心横跨TDP-43低复杂性结构域的282-360个残基,并采用了先前未描述的双螺旋形折叠,这与体外形成的TDP-43丝状结构没有相似性。
 
大量的甘氨酸和中性极性残基促进了大量的转折并限制了β-链的长度,这导致缺乏与交叉β淀粉样结构相关的β-片状堆叠。残基的不均匀分布产生了结构上和化学上不同的表面,这些表面面对外部密度,表明可能有配体结合的位置。这项工作增强了人们对ALS和FTLD分子发病机制的理解,并为开发靶向聚集TDP-43的诊断和治疗药物提供了信息。
 
附:英文原文
 
Title: Structure of pathological TDP-43 filaments from ALS with FTLD

Author: Arseni, Diana, Hasegawa, Masato, Murzin, Alexey G., Kametani, Fuyuki, Arai, Makoto, Yoshida, Mari, Ryskeldi-Falcon, Benjamin

Issue&Volume: 2021-12-08

Abstract: The abnormal aggregation of TAR DNA-binding protein 43kDa (TDP-43) in neurons and glia is the defining pathological hallmark of the neurodegenerative disease amyotrophic lateral sclerosis (ALS) and multiple forms of frontotemporal lobar degeneration (FTLD)1,2. It is also common in other diseases, including Alzheimer’s and Parkinson’s. No disease-modifying therapies exist for these conditions and early diagnosis is not possible. The structures of pathological TDP-43 aggregates are unknown. Here we used cryo-electron microscopy to determine the structures of aggregated TDP-43 in the frontal and motor cortices of an individual who had ALS with FTLD and from the frontal cortex of a second individual with the same diagnosis. An identical amyloid-like filament structure comprising a single protofilament was found in both brain regions and individuals. The ordered filament core spans residues 282–360 in the TDP-43 low-complexity domain and adopts a previously undescribed double-spiral-shaped fold, which shows no similarity to those of TDP-43 filaments formed in vitro3,4. An abundance of glycine and neutral polar residues facilitates numerous turns and restricts β-strand length, which results in an absence of β-sheet stacking that is associated with cross-β amyloid structure. An uneven distribution of residues gives rise to structurally and chemically distinct surfaces that face external densities and suggest possible ligand-binding sites. This work enhances our understanding of the molecular pathogenesis of ALS and FTLD and informs the development of diagnostic and therapeutic agents that target aggregated TDP-43.

DOI: 10.1038/s41586-021-04199-3

Source: https://www.nature.com/articles/s41586-021-04199-3

期刊信息

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:43.07
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html