由Legionella pneumophila效应蛋白MavH介导的膜依赖性actin聚合
Qing Zhang1,2, Min Wan1,2, Elena Kudryashova3
1Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America.
PLoS pathogens
|July 18, 2023
概括
军菌MavH效应蛋白重塑宿主actin细胞骨架,促进细菌进入细胞. 这种机制涉及到actin组装和膜管道,这对于早期感染阶段至关重要.
科学领域:
- 微生物学 微生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 莱吉欧内拉肺炎 (L. pneumophila) 感染了含有莱吉欧内拉的真空细胞 (LCV) 中的真核细胞.
- 通过控制L. pneumophila感染的IV型分泌系统传递的330多种效应蛋白.
- 宿主细胞的行为动态对于细胞内细菌病原体的生存至关重要.
研究的目的:
- 为了研究Legionella效应蛋白MavH的功能.
- 阐明MavH影响宿主细胞actin细胞骨和膜动态的机制.
- 确定MavH在L. pneumophila感染早期阶段的作用.
主要方法:
- 在真核细胞中MavH的异胎表达.
- 焦显微镜分析MavH局部化和行为体重塑.
- 在体外基于脂质体的测试来研究actin组装和膜管道.
- 生物化学测试以确定蛋白质相互作用域.
主要成果:
- MavH局限于内分泌体,并以酸氨基3-酸盐 (PI(3) P) 依存的方式重塑动因细胞骨架.
- MavH通过其CPI动机和WH2-like域来招募宿主actin封闭蛋白 (CP) 和actin.
- MavH刺激PI(3) P脂质体上的活性蛋白组合,诱导膜管道并负调节F-活性蛋白密度.
- 在早期感染期间,MavH被招募到LCV中,并促进细菌的进入.
结论:
- MavH采用了一种通过PI(3) P依赖性actin聚合的膜管道新机制.
- MavH 调节宿主活性,以促进 L. pneumophila 进入宿主细胞.
- MavH在L. pneumophila感染的早期病变发生中发挥着重要作用.
相关概念视频
Mechanism of Filopodia Formation
2.4K
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...
2.4K
Mechanism of Lamellipodia Formation
2.6K
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
2.6K
Actin Polymerization and Cell Motility
5.3K
Actin is a family of globular proteins that are highly abundant in eukaryotic cells. It makes up approximately 1-5% of total cell protein concentration. Actin monomers polymerize to form a complex network of polarized filaments, the actin cytoskeleton, that plays a crucial role in many cellular processes, including cell motility, division, endocytosis, and metastasis of cancer cells.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate....
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate....
5.3K
Actin Polymerization
6.7K
Actin polymerization occurs through the head-to-tail association of binding sites on monomeric actin or G-actin to form filamentous or F-actin. The polymerization can be divided into three phases ̶ nucleation, elongation, and steady-state phase.
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
6.7K
Generation of Straight or Branched Actin Filaments
2.9K
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...
2.9K
Cytoskeletal Proteins in Bacteria
3.5K
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.5K


