不对称的播种屏障在三重和四重复的丝中的合规基础
Ayisha Siddiqua1, Yin Luo, Virginia Meyer
1Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, USA.
Journal of the American Chemical Society
|June 5, 2012
概括
阿尔茨海默病的丝显示了三重复 (3R) 和四重复 (4R) 的独特结构. 这种差异解释了异型之间的播种障碍,影响了疾病的进展.
科学领域:
- 神经科学是一个神经科学.
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 陶氏病理是阿尔茨海默病的核心,涉及蛋白质丝沉积.
- 这些细丝被建议通过种子转换像子一样传播.
研究的目的:
- 为了研究三重复 (3R) 和四重复 (4R) 丝之间的形状差异.
- 为了建立一个分子基础,观察到异型之间的播种障碍.
主要方法:
- 使用了双电子电子共振 (DEER) 谱学.
- 采用广泛的计算分析来测量距离.
- 分析了陶纤维的第三次重复中的旋转标签.
主要成果:
- 证明3R和4R丝具有不同的构造.
- 鉴定出tau粉样纤维作为U转动图案的集体.
- 发现3R丝在结构上是均的,而4R丝是异质的,至少有三个符合性.
结论:
- 建立了不同异形之间的播种屏障的分子基础.
- 介绍了一种研究粉样纤维素组成和动态的新方法.
相关概念视频
Generation of Straight or Branched Actin Filaments
The straight or branched structure formation of actin filaments is controlled by nucleating proteins such as the formins and Arp2/3 complex. Formin-mediated assembly results in straight filaments, whereas Arp2/3 protein complex-mediated assembly results in branched actin filaments.
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Assembly of Cytoskeletal Filaments
Cytoskeletal filaments are polymeric forms of smaller protein subunits. However, individual cytoskeletal filaments may easily disassemble or associate with other similar filaments to form rigid structures. Microfilaments, made of actin monomers, rely on actin-binding proteins to form bundles and create networks of individual actin filaments. Microtubules rely on microtubule-associated proteins (MAPs) to form sturdy cylindrical structures. However, the proteins involved in forming complex...
Amyloid Fibrils
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Mechanism of Filopodia Formation
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Formation of Intermediate Filaments
Intermediate filaments are cytoskeletal proteins with higher tensile strength and flexibility than microfilaments and microtubules. Unlike the other two cytoskeletal proteins, intermediate filament formation lacks the enzymatic activity to hydrolyze nucleotides like ATP and GTP to generate energy for polymerization. Therefore, the formation of intermediate filaments is multistep self-assembly. The involvement of any accessory proteins in intermediate filament formation has not yet been reported.
Tail-anchoring of Proteins in the ER Membrane
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...


