相关实验视频
Updated: May 27, 2025

08:19
In Vitro Assessment of Cardiac Function Using Skinned Cardiomyocytes
Published on: June 22, 2020
6.1K
与过度缩小心肌病相关的A331P动因变体增强了基底收缩活动,并引起休息肌肉功能障碍
Matthew H Doran1, Michael J Rynkiewicz1, Evan Despond2
1Department of Pharmacology, Physiology & Biophysics, Boston University Chobanian & Avedisian School of Medicine, 72 E. Concord St, Boston, MA 02118, USA.
iScience
|February 21, 2025
概括
通过改变actin-tropomyosin相互作用,A331P心脏动因突变导致肌肉过度收缩. 这项研究揭示了这种突变如何通过增加静止肌肉活动导致多变性心肌病.
科学领域:
- 心血管生物学 心血管生物学
- 肌肉生理学 肌肉生理学
- 分子遗传学 分子遗传学
背景情况:
- 增高性心肌病变 (HCM) 是一种遗传性心脏病.
- 心脏动蛋白中的A331P突变与HCM有关,但其精确的机制尚不清楚.
- 在调节肌肉收缩方面,actin-tropomyosin相互作用至关重要.
研究的目的:
- 阐明由A331P心脏动因突变引起的过度缩性心肌病变的机制基础.
- 为了研究A331P突变对actin-tropomyosin相互作用和肌肉收缩性的影响.
主要方法:
- 采用了多学科的方法,包括转基因Drosophila模型和体外生化分析.
- 使用重组的人类心脏动因复制的A331P细丝.
- 进行了冷电子显微镜 (Cryo-EM) 和in silico分子动力学模拟.
主要成果:
- 转基因Drosophila表达A331P动因显示了骨肌肉过度收缩和心肌活性升高.
- 试验室研究显示,在低度下,A331P细纤维的基于髓的滑动速度增加.
- 低温EM没有显示F-actin的结构变化,但in silico分析表明流动性降低和变化的热氨酸相互作用.
结论:
- 心脏动因中的A331P突变破坏了正常的动因-热菌素相互作用,导致休息肌肉活动增加.
- 这些改变的相互作用可能有助于过度缩性心肌病变的发病.
- 这些发现提供了A331P突变和疾病发展之间的机制联系.
相关概念视频
Actin Polymerization and Cell Motility
5.1K
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....
5.1K
The Role of Actin and Myosin in Non-muscle Cells
3.4K
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...
3.4K
Actin and Myosin in Muscle Contraction
8.5K
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...
8.5K
Introduction to Actin
4.8K
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...
4.8K
The Sarcomere
7.5K
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...
Each...
7.5K
Cross-bridge Cycle
116.6K
As muscle contracts, the overlap between the thin and thick filaments increases, decreasing the length of the sarcomere—the contractile unit of the muscle—using energy in the form of ATP. At the molecular level, this is a cyclic, multistep process that involves binding and hydrolysis of ATP, and movement of actin by myosin.
116.6K

