植物"ヘルパー"免疫受容体は,Ca2+浸透性非選択性カチオンチャネルである

Pierre Jacob¹, Nak Hyun Kim¹, Feihua Wu^2,3

¹Department of Biology and Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.

Science (New York, N.Y.)

|June 18, 2021

まとめ

細胞死を制御するカルシウムチャネルを形成しますこの発見によりこれらの重要なタンパク質が植物防御信号伝達経路を直接制御する仕組みが明らかになりました

科学分野:

植物免疫
分子生物学
セル・シグナル

背景:

植物核酸結合レシプター (NLR) は,植物免疫およびプログラム細胞死亡の重要な調節因子である.
サブファミリー
助手
NLRは,多くの細胞の機能に不可欠な構成要素として機能します.
センサー
NLRsは,プラント防衛で.

研究の目的:

ヘルパーNLRs,特にNRG1.1とADR1が植物免疫と細胞死を調節する分子機構を調査する.
ヘルパーNLRが直接カルシウムシグナル伝達に関与するイオンチャネルを形成するかどうかを判断する.

主な方法:

NRG1.1 オリゴメリゼーションと局所化を研究する生化学的測定法.
植物とヒトの細胞におけるカルシウムイオン (Ca2+) 流入を評価するための機能分析
電子生理学的記録 (全細胞の電圧クラップ) が,イオンチャネル活動を特徴づけている.
オリゴメリゼーション,局所化,タンパク質の充電に影響を与える変異体を用いた遺伝分析.

主要な成果:

活性NRG1.1は小分子化し,プラズマ膜に局所化し,植物とヒトの細胞の両方でCa2+の流入を媒介する.
NRG1. 1依存のCa2+流入と細胞死は,Ca2+チャネル阻害剤に敏感であり,オリゴメリゼーションや膜標的化に影響する変異によって低下した.
NRG1.1 と ADR1 を含むヘルパーNLRは,Ca2+ 透過性カチオンチャネルを形成し,細胞質のCa2+ レベルと細胞死を直接調節することが示された.

結論:

ヘルパーNLRは,Ca2+を通過する直接的なカチオンチャネルとして機能する.
これらのチャネルは植物免疫における細胞死信号の変換に不可欠です.
N末端の負の電荷の残留物は,ヘルパーNLRのCa2+流入と細胞死機能に不可欠である.

さらに関連する動画

07:17

Single-Cell Calcium Imaging for Studying the Activation of Calcium Ion Channels

Published on: December 13, 2024

1.2K

08:21

Real-time In Vivo Recording of Arabidopsis Calcium Signals During Insect Feeding Using a Fluorescent Biosensor

Published on: August 15, 2017

13.1K

関連する概念動画

01:12

Mechanically-gated Ion Channels

7.1K

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...

7.1K

01:19

Ion Channels

89.4K

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...

89.4K

01:25

Cell Signaling in Plants

5.9K

Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the changing environmental conditions. Plant signaling is distinct from animal signaling. Plants primarily utilize enzyme-linked receptors, whereas the largest class of cell-surface receptors in animals are G-protein coupled receptors (GPCRs). Unlike animals, receptor tyrosine kinases are rare in plants. Instead, plants have a diverse class of...

5.9K

01:16

Calmodulin-dependent Signaling

5.5K

Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...

5.5K

01:24

Non-gated Ion Channels

7.6K

Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism....

7.6K

01:21

G-Protein Gated Ion Channels

5.1K

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...