交换机I中的突变改变了肌Va的负载依赖性动力学
Christopher Marang1, Brent Scott1, James Chambers2
1Department of Kinesiology, University of Massachusetts, Amherst, MA, 01003, USA.
Nature communications
|May 30, 2023
概括
肌肉蛋白 Va 和 肌肉蛋白 Va.
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:
- 氨酸Va是一种分子电机,对于细胞内运输至关重要.
- 氨酸中ATP水解到机械工作的机制尚未完全理解.
- 电动冲击和酸盐释放的精确时间是一个关键的未知因素.
研究的目的:
- 为了研究高酸盐 (Pi) 对氨酸Va产生力的能力的影响.
- 为了确定电阻负荷如何影响Pi诱导的脱离actin的速度.
- 阐明特定的髓Vα区域在酸盐释放机制中的作用.
主要方法:
- 采用激光陷测定,使用小组合的髓Va S1 (野生类型和S217A突变).
- 多种激光陷刚度,以应用不同的电阻负荷.
- 使用贝尔近似量化Pi诱导的脱落率.
主要成果:
- 野生类型的myosin Va在增加负载时产生更高的力和位移,并增加了Pi.
- 结合事件的寿命在30mM Pi的存在下显著减少.
- 开关I (S217A) 的突变使Pi诱导脱离的负载依赖性增加了七倍.
结论:
- 结果表明,电动冲击可能会在Pi释放前从VA菌素中的活性部位释放.
- 开关I中的S217A突变可能在调节Pi重结的负载依赖性方面发挥作用.
- 这项研究提供了关于肌素Va功能的机械化学合的见解.
相关概念视频
Overview of Myosin Structure and Function
4.5K
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...
4.5K
The Role of Actin and Myosin in Non-muscle Cells
3.6K
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...
3.6K
Actin and Myosin in Muscle Contraction
13.5K
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...
13.5K
Role of Myosin in Cell Migration
2.3K
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....
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....
2.3K
ATP Synthase: Mechanism
14.8K
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased...
14.8K
ATP Driven Pumps III: V-type Pumps
3.8K
V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient.
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
3.8K


