马德28是一种深分支磁动性细菌中保存的类似actin的蛋白质,表现出细胞曲率依赖的局部化
Rino Shimoshige1, Hirokazu Shimoshige2,3, Azuma Taoka4,5
1Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa, Japan.
Journal of bacteriology
|November 24, 2025
概括
磁触性细菌使用两种不同的类似actin的蛋白质,MamK和Mad28,用于磁体的定位. 与MAMK不同的是,Mad28能够感知细胞膜曲率,从而揭示出新的细菌细胞骨功能.
科学领域:
- 微生物学 微生物学
- 细胞生物学 细胞生物学
- 生物物理学的生物物理.
背景情况:
- 磁触性细菌 (MTB) 使用磁体体进行导航,磁体体由类似于actin的蛋白 MamK.定位.
- MTB 拥有第二种类似actin的蛋白 Mad28,其在磁体组定位中的功能基本上是未知的.
研究的目的:
- 在磁体位定位中描述Mad28的结构和功能.
- 为了研究Mad28和MamK在磁触性细菌中的不同作用.
- 探索Mad28在感知细胞几何学方面的潜在作用.
主要方法:
- 免疫涂抹,免疫光显微镜和相关光和电子显微镜证实了Mad28的定位.
- 在 *Magnetospirillum magneticum* 的功能性测试中,AMB-1 测试了磁体位定位的 Mad28 和 MamK 救援.
- 在大肠杆菌中的活细胞成像和局部化研究探索了Mad28与细胞形状的相互作用.
主要成果:
- 马德28在*Solidesulfovibrio magneticus* RS-1中特定地定位在磁体体上.
- MamK,但不是Mad28,在*M.magneticum*AMB-1中拯救了静态磁体位定位表型,表明了功能分歧.
- 马德28在大肠杆菌中显示了依赖曲率的局部化,这表明它感知了膜几何.
结论:
- 马德28和马姆K代表着不同的细胞骨系统,有助于在深分支MTB中磁体组定位.
- 马德28在感知膜曲率方面具有新的功能,这种特性以前没有在细菌的类似活性蛋白中观察到.
- 这些发现为细菌中复杂的细胞骨介导的有机体定位机制提供了新的见解.
相关概念视频
Cytoskeletal Proteins in Bacteria
4.1K
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...
4.1K
Generation of Straight or Branched Actin Filaments
3.7K
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...
3.7K
Other Unique Bacteria
397
Magnetic bacteria exhibit a directed movement called magnetotaxis, driven by structures called magnetosomes. These magnetosomes consist of chains of magnetic particles made of either magnetite (Fe₃O₄) or greigite (Fe₃S₄) and are organized in a linear conformation by a protein scaffold within invaginations of the cell membrane. The bacteria align along the north–south magnetic field lines, much like a compass needle. They are typically microaerophilic or anaerobic...
397
Actin Polymerization and Cell Motility
6.4K
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....
6.4K
Mechanism of Filopodia Formation
3.0K
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...
3.0K
Mechanisms of Membrane-bending
3.2K
The living membranes are flexible due to their fluid mosaic nature; however, their bending into different shapes is an active process regulated by specific lipids and proteins. The membrane bending can be transient as seen in vesicles or stable for a long time as in microvilli. Cells regulate the size, location, and duration of the membrane curvature.
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
3.2K


