机械激活离子通道的结构OSCA2.3揭示了跨膜领域的移动元素
Sebastian Jojoa-Cruz1, Batuujin Burendei1, Wen-Hsin Lee1
1Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Structure (London, England : 1993)
|December 16, 2023
概括
在OSCA家族中,机械激活的离子通道表现出形状的多样性. 研究人员使用冷电子显微镜揭示了OSCA1.2和OSCA2.3内部的不同结构状态和相互作用,进步了机械感应的理解.
科学领域:
- 植物生物学 植物生物学
- 分子和细胞生物学分子和细胞生物学
- 生物物理学的生物物理.
背景情况:
- OSCA/TMEM63家族蛋白质是关键的机械激活离子通道.
- 之前的结构研究提供了静态观点,限制了对机械感应机制的理解.
- 关于这些通道内的动态形状变化的信息有限.
研究的目的:
- 为了研究阿拉比多普西斯·塔利亚纳 (Arabidopsis thaliana) 的高分辨率结构,OSCA1.2和OSCA2.3.
- 探索OSCA家族内的构造异质性和保存相互作用.
- 阐明这些离子通道中机械感应的结构基础.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定蛋白质结构.
- 在盘中对OSCA1.2和OSCA2.3进行高分辨率结构分析.
- 同进化序列分析以确定保存的蛋白相互作用.
主要成果:
- OSCA1.2的结构与之前报告的结构一致.
- OSCA2.3 呈现出独特的 TM6a-TM7 链接体构造,缩小了细胞质孔.
- 确定了TM6a-TM7链接器和束状域 (BLD) 之间的保守相互作用.
结论:
- 欧斯卡家族成员表现出显著的形状异质性.
- 观察到保守相互作用的差异,特别是涉及TM6a-TM7链接器和BLD.
- 这些发现提供了关于机械敏感离子通道功能的动态性质的见解.
相关概念视频
Mechanically-gated Ion Channels
6.4K
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
6.4K
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
Ion Channels
87.0K
The movement of ions like sodium, potassium, and calcium into and out of the cell is essential to maintain the electrochemical gradient in living cells. The ion channels—a class of membrane transport proteins—help maintain this ionic gradient for the smooth functioning of physiological activities such as maintaining cell size and volume, conducting nerve impulses, and gas and nutrient exchange.
Ion channels are specialized integral membrane proteins on the plasma membrane that allow...
Ion channels are specialized integral membrane proteins on the plasma membrane that allow...
87.0K
Ligand-Gated Ion Channel Receptor: Gating Mechanism
2.3K
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
2.3K
Multi-pass Transmembrane Proteins and β-barrels
5.3K
In multi-pass transmembrane proteins, the polypeptide chain crosses the membrane more than once. The transmembrane polypeptide chain either forms an α-helix or β-strand structure. α-Helix containing multi-pass transmembrane proteins are ubiquitous, whereas β-strand containing ones are mainly found in gram-negative bacteria, mitochondria, and chloroplasts.
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as...
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as...
5.3K
Electrochemical Gradient and Channel Proteins: An Overview
2.3K
An electrochemical gradient is a fundamental concept in biology and chemistry. It regulates the movement of ions across cell membranes. This movement is influenced by two factors:
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to...
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to...
2.3K


