相关实验视频
Updated: Jun 27, 2025

09:52
A Fluorescence-based Assay of Phospholipid Scramblase Activity
Published on: September 20, 2016
13.9K
通过TMEM16蛋白质进行封闭槽混杂的结构基础
Zhang Feng1, Omar E Alvarenga2, Alessio Accardi3,4,5
1Department of Anesthesiology, Weill Cornell Medical College, New York, NY, USA.
Nature structural & molecular biology
|April 29, 2024
概括
激活的TMEM16scramblases将脂质移动到信号中. 这项研究可视化了真菌TMEM16的封闭沟中的脂质相互作用,揭示了沟开放和脂质杂乱的分子步骤.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 膜生物物理学 膜生物物理学
背景情况:
- TMEM16 scramblases是依赖的离子通道,可以调节膜脂不对称.
- 通过TMEM16scramblases对酸胺酶的外部化对于细胞信号通路至关重要.
- 现有的模型提出了脂质变形和槽动力学,但分子机制仍然不清楚.
研究的目的:
- 阐明依赖的TMEM16 scramblase激活的分子机制.
- 为了可视化菌TMEM16 (nhTMEM16) 的闭槽中的脂质相互作用.
- 为了确定关键的结构重排和脂蛋白相互作用涉及到杂乱.
主要方法:
- 纳米磁盘中的Ca2+结合的真菌nhTMEM16的冷电子显微镜 (冷EM).
- 功能性脂质结合测试.功能性脂质结合测试.
- 对TMEM16形状和脂质相互作用的结构和生化分析.
主要成果:
- 在Ca2+结合的nhTMEM16.16的闭槽中直接可视化脂质协会.
- 确定关键的脂质-蛋白质相互作用点,用于闭槽混杂.
- 在TM6螺旋中,槽打开的结构证据涉及连续的pi-helical转.
- 证明脚手架蛋白质和脂质对nhTMEM16形状和冷EM结构确定的影响.
结论:
- 这项研究揭示了TMEM16杂酶激活和脂质杂的分子基础.
- 槽口的开放涉及TM6螺旋体中的动态结构重排.
- 脚手架蛋白质和脂质在TMEM16的构造和结构研究中起着重要作用.
相关概念视频
Membrane Asymmetry Regulating Transporters
4.5K
Enzymes like flippase, floppase, and scramblase transfer phospholipids from one layer to another in the membrane, thereby affecting membrane asymmetry.
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
4.5K
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
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
Translocation of Proteins into the Mitochondria
3.1K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
3.1K
Mechanisms of Membrane-bending
2.7K
The living membranes are flexible due to their fluid mosaic nature; however, their bending into different shapes is an active process regulated by specific lipids and proteins. The membrane bending can be transient as seen in vesicles or stable for a long time as in microvilli. Cells regulate the size, location, and duration of the membrane curvature.
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
2.7K
Protein Translocation Machinery on the ER Membrane
4.6K
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
4.6K

