在Dictyostelium discoideum中表达和描述一个功能性肌素头部碎片的表达和特征
D J Manstein1, K M Ruppel, J A Spudich
1Department of Cell Biology, Stanford University School of Medicine, CA 94305.
Science (New York, N.Y.)
|November 3, 1989
概括
研究人员从Dictyostelium discoideum中表达和净化了一个功能性肌肉素头部片段 (子片段1). 这种重组的运动蛋白片段支持活性丝的滑动,这对肌肉收缩和细胞运动至关重要.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 肌是一种运动蛋白质,对细胞运动至关重要.
- 头部域 (子片段1) 负责actin相互作用和ATP水解.
- 了解肌肉蛋白的功能需要研究其孤立的域.
研究的目的:
- 为了表达和净化一个功能性的重组肌肉素头部片段 (子片段1).
- 为了表征复合肌肉素片段的生物化学和运动性质.
- 为了证实肌素亚片1在丝丝滑动中的作用.
主要方法:
- 在Dictyostelium discoideum中克隆和表达Dictyostelium myosin重链基因片段.
- 复合肌肉素亚片的净化 1. 复合肌肉素亚片的净化
- 生物化学试验:用轻链进行共净化,与乙烯酸结合,ATPase活性.
- 在体外运动性测试.
主要成果:
- 成功表达和净化了一个功能性重组肌肉素头部片段 (子片段1).
- 净化的碎片与基本和调节光链共净化.
- 再组合的髓片段显示了由actin激活的ATPase活性.
- 试管体内运动性测试证实了碎片能够支持活性丝的滑动.
结论:
- 再组合肌肉素头部片段是功能性的,并保留了关键的运动活动.
- 这项研究提供了一种生产活性肌肉酶运动域的方法,用于进一步研究.
- 这些发现证实了肌素亚片1在产生细胞运动力的作用.
相关概念视频
01:15Overview of Myosin Structure and Function
Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with their role in muscle contraction, these proteins also play a role in the intracellular transport of molecules and vesicles. There are twenty-four classes of myosins based on their domain sequence and organization. Of the twenty-four, six classes (Myosin I, Myosin II, Myosin V, Myosin VI, Myosin VII, and Myosin X) have been well characterized.
01:16Actin and Myosin in Muscle Contraction
Actin and myosin are contractile proteins that form the sarcomere found in skeletal muscle tissues for regulating muscle contraction. Actin, a globular contractile protein, interacts with myosin for muscle contraction. The skeletal tissue appears striped or striated under a microscope due to the repeated arrangement of contractile proteins actin and myosin along the length of myofibrils. Dark A bands and light I bands repeat along myofibrils, and the alignment of myofibrils in the cell causes...
01:10The Role of Actin and Myosin in Non-muscle Cells
Actin and myosin or actomyosin filaments also play a significant role in cells other than those involved in muscle contraction (which occurs within the sarcomere of muscle cells). The mechanism of non-muscle cell contractile bundles was first observed in Dictyostelium and Acanthamoeba. In non-muscle cells, two bundles are commonly found: stress fibers and actomyosin adherence belts. These contractile bundles are smaller and less organized than the ones found in muscle cells. They are held...
01:13Actin 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.
01:18Role of Myosin in Cell Migration
Myosins are multimeric motor proteins involved in various cellular processes such as migration, adhesion, and proliferation. Myosin II is the most common type in animal cells, which binds and cross-links actin filaments.
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...
01:08The Sarcomere
A sarcomere is a microscopic segment repeating in a myofibril. The sarcomere fundamentally consists of two main myofilaments: thick filaments called myosin and thin filaments called actin. These filaments interact by sliding past each other in response to stimulus. In addition to myosin and actin, several other proteins, such as tropomyosin, troponin, titin, nebulin, myomesin, α-actinin, and dystrophin, play crucial roles in regulating, structuring, and functioning of the sarcomere.
Each myosin...
Each myosin...