鉴定Dictyostelium中的一种actin结合蛋白作为延长因子1a
1Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461.
Nature
|October 4, 1990
概括
蛋白质延长因子1a (EF-1a) 结合于活性丝,将蛋白质合成与细胞骨联系起来. 这种相互作用在细胞运动期间受到调节,可能控制蛋白质生产的位置和时间.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 间接证据表明细胞骨和蛋白质合成机制之间存在联系.
- 之前的研究表明,延长因子1a (EF-1a) 与微管细胞骨架有关.
- 新出现的数据表明细胞骨蛋白mRNAs与行为丝有关.
研究的目的:
- 为了研究ABP-50,一种在Dictyostelium discoideum中活性丝捆绑蛋白的作用.
- 为了确定ABP-50是否与已知的蛋白质合成因子有关.
- 为了阐明actin细胞骨动力学和蛋白质合成调节之间的功能联系.
主要方法:
- 从Dictyostelium discoideum中分离和描述ABP-50.
- 免疫光显微镜以确定ABP-50的定位.
- 补充DNA测序和功能分析.
- 生物化学测试以评估actin结合性质.
主要成果:
- ABP-50是一种丰富的50K活性丝捆绑蛋白质,在filopodia和皮层区域中发现.
- ABP-50在细胞质中结合单体性actin,其与actin细胞骨的关联在化疗过程中受到调节.
- 鉴定出ABP-50是Dictyostelium discoideum EF-1a. 这种植物的名称.
- 在刺激时,EF-1a表现出可逆的结合到actin细胞骨架.
结论:
- 在功能上,ABP-50与Dictyostelium discoideum EF-1a完全相同.
- EF-1a与actin细胞骨架的调节相互作用为蛋白质合成的空间和时间控制提供了一种机制.
- 这一发现弥合了对细胞骨动力学和真核细胞中蛋白质合成调节的理解.
相关概念视频
Introduction to Actin
Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle cells, while in non-muscle cells, it is lower and makes up around 1–5 percent of the total cell protein. Actin found in the unicellular amoebae and complex multicellular animals is around 80% similar, demonstrating their conservation over a billion years of evolution. Actin coding genes are conserved within species and across different species.
Actin Polymerization
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 actin...
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 actin...
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...
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.
Mechanism of Filopodia Formation
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...


