微纤维系统中的冗余性:缺少两个F-actin交联蛋白的Dictyostelium细胞的异常发展
W Witke1, M Schleicher, A A Noegel
1Max Planck Institute for Biochemistry, Martinsried, Federal Republic of Germany.
Cell
|January 10, 1992
概括
缺乏α-actinin和凝因子的Dictyostelium细胞显示出发育受损,特别是在果实体形成方面. 这种缺陷通过与野生类型细胞混合或重新引入α-actinin来挽救,这表明蛋白质网络相互作用.
科学领域:
- 细胞生物学 细胞生物学
- 发展生物学 发展生物学
- 生物化学 生物化学
背景情况:
- 动氨酸结合蛋白对细胞结构和功能至关重要.
- α-actinin和凝因子是Dictyostelium中关键的F-actin交叉链接蛋白.
- 这些蛋白在多细胞发育中的特定作用尚未完全理解.
研究的目的:
- 为了研究alpha-actinin和凝因子在Dictyostelium发育中的功能.
- 为了确定这些蛋白质的缺失是否会影响基本的细胞过程.
- 阐明导致发育缺陷的分子机制.
主要方法:
- 基因破坏被用来创造缺乏α-actinin和凝因子的Dictyostelium双重突变.
- 评估了细胞功能,包括生长,化疗,细胞和皮诺细胞.
- 进行了发育分析,包括聚合物形成和果实体发育.
- 进行了与野生类型细胞和基因再引入的补充试验.
主要成果:
- 双重突变的Dictyostelium表现出正常的生长,化学反应,细胞和皮诺细胞.
- 发育严重受损,很少形成果实体.
- 混合突变体与野生类型细胞挽救了果实体的形成.
- 在发育过程中基因表达模式在突变者中保持不变.
- 功能性α-actinin的重新引入恢复了正常发育.
结论:
- F-actin交叉链接蛋白质α-actinin和凝因子对于Dictyostelium多细胞发育至关重要,但对于基本的细胞功能来说并非如此.
- 发育缺陷是由于缺少这些蛋白质而引起的形态遗传问题.
- 可能存在一种功能性actin结合蛋白质网络,允许相互补充.
- 这些发现凸显了在编排发育过程中,actin结合蛋白的复杂相互作用.
相关概念视频
Adaptability of Cytoskeletal Filaments
6.9K
The cytoskeleton is a complex dynamic structure performing varied functions based on cellular requirements. The adaptability of the individual filaments in the cytoskeleton determines their ability to perform various functions within the cell. It can undergo rapid reorganization during processes like cell division or remain stable for several hours as in the interphase. The adaptability of these filaments depends on stringent regulatory mechanisms. The microfilament and microtubules of the...
6.9K
Actin Filament Depolymerization
4.2K
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...
4.2K
Microtubule Instability
6.5K
Microtubules are hollow cylindrical filaments having a diameter of approximately 25 nm and a length that varies from 200 nm to 25 μm. GTP-bound tubulin subunits form αβ-heterodimers for microtubule assembly. These core building blocks interact longitudinally, polymerizing into protofilaments. The protofilaments then interact with one another through lateral bonding forces to form stable cylindrical microtubules. These cylindrical filaments are dynamic as they undergo repeated...
6.5K
The Contractile Ring
7.5K
Contractile rings are composed of microfilaments and are responsible for separating the daughter cells during cytokinesis. Contractile ring assembly proceeds along with other cell cycle events; however, very few mechanistic details are known about the timing and coordination of the contractile rings with the cell cycle.
A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
7.5K
Mechanism of Filopodia Formation
3.5K
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...
3.5K
Disassembly of Intermediate Filaments
2.9K
Intermediate filaments (IFs) do not undergo spontaneous disassembly. Enzymes, kinases, and phosphatases add and remove phosphates from specific sites to regulate their disassembly. The IF concentration in the cytoplasm also regulates the disassembly. If the concentration crosses a threshold, it activates the protein kinases in the vicinity, allowing the phosphorylation of IFs.
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
2.9K


