作用因子网络的可逆应力软化
Ovijit Chaudhuri1, Sapun H Parekh, Daniel A Fletcher
1UC San Francisco /UC Berkeley Joint Graduate Group in Bioengineering and Department of Bioengineering, University of California at Berkeley, Berkeley, California 94720, USA.
Nature
|January 19, 2007
概括
细胞的机械特性至关重要. 动氨酸网络表现出应力软化,原因是压缩下丝的曲,揭示了细胞力学中的复杂弹性.
科学领域:
- 细胞力学 细胞力学
- 生物物理学的生物物理.
- 细胞骨动力学 细胞骨动力学
背景情况:
- 动氨酸丝网对于细胞力学至关重要,它会影响硬度和力传递.
- 在生理条件下量化体外活性网络的机械性质仍然具有挑战性.
- 之前的研究表明,由于丝延伸阻力,actin网络的应力强化.
研究的目的:
- 为了研究复合的树突性亚丁网络的机械性质.
- 探索压力-应变行为超越简单的硬化在actin网络.
- 了解电线压缩在细胞机械反应中的作用.
主要方法:
- 使用改造的原子力显微镜 (AFM) 进行机械探测.
- 在实验室中重建了树突性活性蛋白网络,模仿了细胞的lamellipodia.
- 应用受控力来观察网络变形和应力-应变关系.
主要成果:
- 在较低负载下观察到应力硬,与之前的发现一致.
- 在较高的施加负载下确定了一种新的可逆应力软化行为.
- 证明应力软化是由于压缩下单个actin丝的弹性曲引起的.
结论:
- 动氨酸网络表现出应力硬化和应力软化,表明复杂的弹性.
- 压缩下丝的弹性曲是可逆软化的一个关键机制.
- 热带弹性和热带弹性之间的这种相互作用决定了actin网络的机械行为.
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...
Actin Filament Depolymerization
Actin filaments (F-actin) are composed of actin subunits. The dissociation of actin monomers can occur from either end of F-actin. The rate of dissociation is faster from the minus-end or the pointed end, where the actin subunits exist with a bound ADP, together known as ADP-actin. The depolymerization of F-actin is aided by proteins, including the actin-depolymerizing factor (ADF) and cofilin family of proteins, gelsolin, and glia maturation factor (GMF).
In F-actin, the ADF/cofilin proteins...
In F-actin, the ADF/cofilin proteins...
Formation of Higher-order Actin Filaments
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 networks...
The high-order actin networks...
Destabilization of Microtubules
The destabilization of microtubules can occur during different stages of the microtubule lifecycle, such as nucleation or elongation. It can take place at either end of the microtubule or in the microtubule lattices as a whole. The lifespan of individual microtubules within a cell varies according to the cell type and stage of the cell cycle. During interphase, the lifespan of the microtubule is about 30 minutes, while during cell division, it is about 15 minutes. In axonal microtubules of...
Actin Polymerization and Cell Motility
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.
Cell-matrix's Response to Mechanical Forces
In animal cells, the extracellular matrix allows cells within tissues to withstand external stresses and transmits signals from the outside of the cell to the inside. The extracellular matrix is extensive, and its composition varies between different types of tissues. For example, the reticular fibers and ground substance make up the ECM in loose connective tissue, while collagen and bone minerals make up the ECM of bone tissue.
Anchoring junctions mechanically attach a cell to the...
Anchoring junctions mechanically attach a cell to the...


