カルシウム-カルモジュリン調節による嗅覚のサイクルヌクレオチドゲートカチオンチャネル

M Liu¹, T Y Chen, B Ahamed

¹Howard Hughes Medical Institute, Baltimore, MD.

Science (New York, N.Y.)

|November 25, 1994

まとめ

カルシウムカルモジュリンは,嗅覚チャネルに直接結合する.

科学分野:

神経科学は神経科学である.
分子生物学は分子生物学である.
バイオケミストリーバイオケミストリー

背景:

イオンチャネルとのカルシウム-カルモジュリン相互作用は一般的ですが,理解は不十分です.
正確な結合部位と調節メカニズムについては,多くのチャンネルでは未だにわかりにくい.

研究の目的:

カルシウム・カルモジュリンとオルファクトリー・サイクル・ヌクレオチド・アクティベート・カチオン・チャネルの間の直接結合相互作用を解明するため.
カルシウムカルモジュリンがチャネル活動を調節する分子機構を理解する.

主な方法:

直接結合を確認するための生化学的測定法.
チャネルゲッティングとリガンド親和度の変化を評価するための機能研究.

主要な成果:

カルシウムカルモジュリンは,嗅覚チャネルのアミノ端にある特定のドメインに直接結合する.
この結合イベントは,チャネルゲーティングを変化させることで,循環性核酸に対するチャネルの親和性を減少させます.
観察されたメカニズムは,カルモジュリンの酵素の調節に並行しています.

結論:

嗅覚チャネルのアミノ端は,重要なゲーティング要素である.
この研究は,イオンチャネル機能のカルモジュリン媒介制御メカニズムを明らかにしています.
この発見は,構造が類似したイオンチャネルを理解する上で大きな意味を持つ可能性がある.

さらに関連する動画

11:35

Flash Photolysis of Caged Compounds in the Cilia of Olfactory Sensory Neurons

Published on: October 29, 2011

09:07

Fluorescent Calcium Imaging and Subsequent In Situ Hybridization for Neuronal Precursor Characterization in Xenopus laevis

Published on: February 18, 2020

関連する概念動画

01:15

Amplifying Signals via Second Messengers

Many receptor binding ligands are hydrophilic; they do not cross the cell membrane but bind to cell-surface receptors. Thus, their message must be relayed by second messengers present in the cell cytoplasm. There are several second messenger pathways, each with its own way of relaying information. For example, the G protein-coupled receptors can activate both phosphoinositol and cyclic AMP (cAMP) second messenger pathways. The phosphoinositol pathway is active when the receptor induces...

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,...

01:27

Feedback Regulation of Calcium Concentration

Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...

01:16

Calmodulin-dependent Signaling

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,...

01:28

Nitric Oxide Signaling Pathway

Nitric oxide (NO), an inorganic gas, acts as a potent second messenger in most animal and plant tissues. NO diffuses out of the cells that produce it and enters the neighboring cells to generate a downstream response. NO synthase (NOS) catalyzes NO production by the deamination of the amino acid arginine. There are three isoforms of NOS. Endothelial cells have endothelial NOS (eNOS), nerve and muscle cells have neuronal NOS (nNOS), and macrophages produce inducible NOS (iNOS) upon exposure to...

01:30

Ligand-Gated Ion Channel Receptor: Gating Mechanism

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...

関連する実験動画