膜局部化在与细胞信号传递相关的条件下加速关联
William Y C Huang1, Steven G Boxer2, James E Ferrell1,3
1Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305.
概括
细胞信号分子在等离子体膜上比在细胞质中更快地结合起来. 这种膜运动优势对于较大的细胞是显著的,但对于较小的细胞是可以忽略不计的.
科学领域:
- 细胞生物学 细胞生物学
- 生物物理学的生物物理.
- 分子动力学分子动力学
背景情况:
- 细胞质分子转移到等离子体膜是细胞信号传递的一个关键过程.
- 由于扩散限制,膜局部化是否增强或阻碍分子间关联率是有争议的.
研究的目的:
- 直接比较溶液 (细胞溶液) 中的DNA链的关联率与支持膜上的关联率.
- 研究细胞大小对膜相关反应的动力优势的影响.
主要方法:
- 利用互补的DNA链作为同一关联反应的模型系统.
- 在散装溶液 (模拟细胞质) 和支持的脂质双层 (模拟血) 中比较反应动力学.
- 测量速率常数以量化关联效率.
主要成果:
- 与10μm半径细胞的细胞质相比,在膜上DNA链的结合速度是22到33倍.
- 膜局部化的动力优势取决于细胞大小.
- 对于小的,约1微米的原生细胞,这种影响是最小的.
结论:
- 血局部化显著提高了较大的细胞中的分子间关联率.
- 这种增强是由增加的二维遭遇率和每次遭遇的更高反应概率驱动的.
- 细胞分离在调节生物过程的反应动力学方面发挥着至关重要的作用.
相关概念视频
Intracellular Signaling Affects Focal Adhesions
2.7K
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
2.7K
Assembly of Signaling Complexes
5.8K
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
5.8K
Mechanisms of Membrane Domain Formation
3.0K
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with...
Another mechanism for membrane domain formation involves membrane proteins interacting with...
3.0K
Cell-surface Signaling
51.8K
Hormones—or any molecule that binds to a receptor, known as a ligand—that are lipid-insoluble (water-soluble) are not able to diffuse across the cell membrane. In order to be able to affect a cell without entering it, these hormones bind to receptors on the cell membrane. When a first messenger, a hormone, binds to a receptor, a signal cascade is set off, causing second messengers, proteins inside the cell, to become activated, resulting in downstream effects.
51.8K
Protein Diffusion in the Membrane
4.4K
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
4.4K
Insertion of Single-pass Transmembrane Proteins in the RER
6.7K
Integral membrane proteins are proteins adhered to the lipid bilayer of a cell organelle or membrane. They can be of two types: transmembrane integral proteins that span the lipid bilayer and monotopic proteins that are attached to either side of the membrane but do not pass through it.
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
6.7K


