ピエゾタンパク質は,機械的に活性化されたチャネルの孔を形成するサブユニットです

Bertrand Coste¹, Bailong Xiao, Jose S Santos

¹Department of Cell Biology, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California 92037, USA.

Nature

|February 21, 2012

まとめ

機械伝導は,圧力感知イオンチャネルに依存しています. この研究は,ピエゾタンパク質が実際にこれらのチャネルであり,触覚と音を感知するための不可欠な構成要素を形成することを明らかにしています.

科学分野:

細胞生物学細胞生物学
バイオフィジックス生物物理学
神経科学は神経科学である.

背景:

メカノトランスデュークションは,触覚や音を感知するなどの生理学的プロセスに不可欠です.
圧力検出を担う特定のカチオンチャネルは,未特定のままでした.
マウスPiezo1とPiezo2は機械的に活性化された電流を誘導するが,毛穴形成チャネルとしての役割は不明であった.

研究の目的:

ピエゾタンパク質が孔を形成するイオンチャネルか変調器かを判断する.
ドロソフィラ・メラノガスター・ピエゾ (DmPiezo) の性質を調査する.
マウスピエゾ1 (MmPiezo1) の構造と機能を記述する.

主な方法:

電気生理学では,機械的に活性化された電流を測定します.
MmPiezo1複合体の構成を決定するための生化学分析.
精製されたMmPiezo1を脂質二重層とリポソームに溶解する.

主要な成果:

DmPiezoは,哺乳類のPiezoタンパク質とは異なる性質を持つ機械的に活性化された電流を誘導する.
MmPiezo1は大きなホモオリゴメリック複合体 (約120万ダルトン) を形成する.
人工膜に再構成された浄化されたMmPiezo1は,機能的な,ルテニウム赤に敏感なイオンチャネルを形成する.

結論:

ピエゾタンパク質は進化的に保存され,孔を形成するイオンチャネルである.
これらのチャネルは,機械伝導に直接関与しています.
この発見は,ピエゾタンパク質を,長い間求められてきた圧力感受性カチオンチャネルとして特定した.

さらに関連する動画

07:32

Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects

Published on: September 1, 2016

Ex Vivo Analysis of Mechanically Activated Ca2+ Transients in Urothelial Cells

05:35

Ex Vivo Analysis of Mechanically Activated Ca²⁺ Transients in Urothelial Cells

Published on: September 28, 2022

関連する概念動画

01:58

Mechanical Protein Functions

Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force.

01:34

ATP Driven Pumps II: P-type Pumps

The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...

01:26

Voltage-gated Ion Channels

Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...

01:12

Mechanically-gated Ion Channels

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...

01:21

G-Protein Gated Ion Channels

GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...