関連する実験動画
Updated: Jan 27, 2026

09:12
Measuring Deformability and Red Cell Heterogeneity in Blood by Ektacytometry
Published on: January 12, 2018
15.4K
ヘモグロビンβ93 システインは赤血球から酸化窒素のバイオアクティビティの輸出には必要ありません
Chiao-Wang Sun1, Jiangning Yang2, Andrei L Kleschyov3,4
1Department of Biochemistry (C.W.S., T.T.), University of Alabama at Birmingham.
Circulation
|March 26, 2019
まとめ
赤血球は,ベータ93システインにおけるS- ニトロゾ (SNO) ヘモグロビン形成とは独立して,酸化窒素 (NO) の生物活性を発揮する. この発見は,NO依存の生理学的反応を媒介するSNO-ヘモグロビンの確立された役割に異議を唱える.
科学分野:
- 生理学
- 生物化学
- 心血管研究
背景:
- ヘモグロビン (Hb) のベータ93システインのS- ニトロゾ (SNO) Hbを形成するニトロゼは,赤血球 (RBC) による酸化窒素 (NO) 排出に不可欠と考えられています.
- このNOの輸出は,低酸素血管拡張や心臓保護のような重要な生理学的機能を媒介すると考えられています.
研究 の 目的:
- 赤血球媒介 NO 生物活性輸出におけるβ93 システイン ニトロゼーションの役割を調査する.
- NO生物活性輸出とその生理学的効果のためにSNO-ヘモグロビン形成が不可欠であるかどうかを判断する.
主な方法:
- 遺伝子組み換えマウスを利用し,ベータ93システインを赤血球でアラニン (ベータ93A) に置き換えた.
- 心臓イシュケミア/再注血および血小板活性化アッセイのex vivoモデルを使用した.
- ネズミの血管反応と in vivo 低酸素血管拡張を評価した.
主要な成果:
- 心臓の回復は,対照群 (β93C) とβ93A赤血球と類似した.
- ベータ93Cとベータ93A赤血球の間で,血小板活性化抑制によって測定されたNOのバイオアクティビティの輸出は同等であった.
- ベータ93Cとベータ93Aの赤血球の間で血管緩解と低酸素血管拡張の反応は有意に異なっており,ベータ93Cのニトロゼーションとは無関係であった.
結論:
- 赤血球はNOのバイオアクティビティを大量に排出する能力を持っています.
- このエクスポートメカニズムは,ヘモグロビンのβ93システイン残基のSNO形成とは無関係に動作する.
- NOのバイオアクティビティの輸出を媒介するSNO-ヘモグロビンの確立された役割は,再評価を必要とする.
関連する概念動画
Nitric Oxide Signaling Pathway
6.2K
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...
6.2K
Hemoglobin
7.8K
Hemoglobin is a globular protein made up of four subunits. Two of these subunits are alpha chains, and the other two are beta chains. Each subunit contains a molecule of heme, which has an iron atom and can bind to oxygen. When an oxygen molecule binds to one heme group, it changes the shape of hemoglobin, making it easier for the other heme groups to bind oxygen as well.
When all four heme groups are bound to oxygen, the resulting molecule is called oxyhemoglobin. As a result, arterial blood...
When all four heme groups are bound to oxygen, the resulting molecule is called oxyhemoglobin. As a result, arterial blood...
7.8K
Export of Mitochondrial and Chloroplast Genes
4.1K
A eukaryotic cell can have up to three different types of genetic systems: nuclear, mitochondrial, and chloroplast. During evolution, organelles have exported many genes to the nucleus; this transfer is still ongoing in some plant species. Approximately 18% of the Arabidopsis thaliana nuclear genome is thought to be derived from the chloroplast’s cyanobacterial ancestor, and around 75% of the yeast genome derived from the mitochondria’s bacterial ancestor. This export has occurred...
4.1K
Nuclear Export
4.9K
The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES.
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
4.9K
Nuclear Export of mRNA
5.4K
5.4K
Nuclear Export of mRNA
8.7K
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
8.7K

