MUC5AC 纤维照亮了呼吸道和肠道粘膜的结构多样化
Meital Haberman1, Roman Kamyshinsky2, Nava Reznik1
1Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
概括
研究人员揭示了MUC5AC的螺旋丝结构,这是一个关键的呼吸道粘膜. 这些结构解释了素单体如何组装成保护性聚合物,为肺部健康和疾病提供了洞察力.
科学领域:
- 葡萄糖蛋白的结构和功能
- 粘膜免疫学 粘膜免疫学
- 生物化学 生物化学
背景情况:
- 分泌的粘膜是保护粘膜组织的大型葡萄糖蛋白,在各个器官中具有不同的功能.
- 由于它们的大小,灵活性和复杂的组装,研究粘蛋白结构具有挑战性.
- MUC5AC和MUC5B是呼吸系统中主要的粘膜.
研究的目的:
- 为了确定一个主要的呼吸道粘素段的高分辨率结构,MUC5AC.
- 阐明MUC5AC聚合和超分子组合的机制.
- 了解MUC5AC结构如何与其在肺部保护和疾病中的功能有关.
主要方法:
- 进行X射线晶体学以确定MUC5AC氨基末端段的结构.
- 与其他粘膜蛋白 (MUC2) 和相关蛋白 (VWF) 的比较分析.
- 氨基酸序列的生物信息分析,以寻找变异和疾病突变.
主要成果:
- MUC5AC的高分辨率结构揭示了螺旋状纤维,与其他已知的粘蛋白结构不同.
- 这些结构支持一种模型,其中非共价相互作用指导二硫化物交联以形成聚合物.
- 表明局部序列变化在保持聚合活性的同时显著影响更高阶组合.
结论:
- MUC5AC螺旋丝结构为了解肺清洁和保护中的呼吸道粘素功能提供了基础.
- 呼吸道和肠道粘膜之间超分子组合的差异可能反映出不同的生理要求.
- MUC5AC结构可视化了人类序列变异和疾病相关突变的部位,有助于未来的研究.
相关概念视频
Mucosal Barrier of the Stomach
433
The gastric glands contain parietal cells that secrete hydrochloric acid (HCl) for digestion. The cells secrete HCl because it is highly corrosive and essential for breaking down food. To achieve this, they secrete hydrogen and chloride ions into the lumen of the gastric glands, which combine to form HCl.
Within parietal cells, carbonic acid is first formed through the reaction of water and carbon dioxide. The dissociation of carbonic acid releases bicarbonate and hydrogen ions. The bicarbonate...
Within parietal cells, carbonic acid is first formed through the reaction of water and carbon dioxide. The dissociation of carbonic acid releases bicarbonate and hydrogen ions. The bicarbonate...
433
Microvilli
5.5K
Microvilli are tiny finger-like projections found on the surface of certain cells. Their purpose is to increase the surface area of the cell's apical surface, resulting in more effective absorption or secretion of substances.
These microvilli are predominantly present in cells lining the small intestine, kidney tubules, and certain cells in the respiratory and reproductive systems. By significantly expanding the surface area of the cell membrane, microvilli enhance the cell's capacity...
These microvilli are predominantly present in cells lining the small intestine, kidney tubules, and certain cells in the respiratory and reproductive systems. By significantly expanding the surface area of the cell membrane, microvilli enhance the cell's capacity...
5.5K
Types of Intermediate Filaments
3.6K
The intermediate filaments are an essential component of the cytoskeleton. Presently six types of intermediate filament have been identified. Type I and II are acidic and basic keratin proteins. Type III is of mesodermal origin and comprises four proteins: vimentin, desmin, glial fibrillary acidic protein (GFAP), and peripherin. Vimentin is commonly found in mesenchymal cells, desmin in muscle cells, GFAP in astrocytes, while peripherin is found in peripheral nervous system neurons (PNS). Type...
3.6K
Generation of Straight or Branched Actin Filaments
2.8K
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...
2.8K
Renewal of Intestinal Stem Cells
2.5K
The intestinal epithelial lining rapidly renews every 4 to 5 days. The renewal is facilitated by intestinal stem cells (ISCs) located at the base of the crypt– a gland located at the bottom of each villus. ISCs divide asymmetrically to form new stem cells and progenitor daughter cells. The daughter cells are called transit-amplifying (TA) cells which move upwards along the crypt and either differentiate into absorptive cells– the enterocytes or secretory cells– including the...
2.5K
Formation of Higher-order Actin Filaments
2.9K
The polymerization of G-actin monomers into filamentous F-actin is a multi-step process. Once the F-actins are formed, they can bundle together in different arrangements to form higher-order networks and regulate cellular functions. Common examples include the formation of lamellipodia and filopodia at the cell's leading edge by actin reorganization in a migrating cell. The microvilli on the brush border epithelial cells are also formed through the F-actin network.
The high-order actin...
The high-order actin...
2.9K


