TIRドメインは細菌の免疫信号としてヒスティジン-ADPRを生成する
Dziugas Sabonis1, Carmel Avraham2, Renee B Chang3,4
1Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania.
Nature
|April 30, 2025
まとめ
バクテリアは新種の免疫シグナル分子を利用し,ADP-リボース (His-ADPR) と結合したヒスティジンを用いて,ファグ感染から防御する. この発見により 新しい細菌の防御メカニズムと 信号分子が明らかになりました
科学分野:
- 分子生物学
- 免疫学
- 生物化学
背景:
- トール/インタールイキン-1受容体 (TIR) ドメインは,生物のパターン認識と免疫反応に不可欠である.
- バクテリアや植物では,TIRドメインのタンパク質は,病原体検出時に,通常,ニュクレオチドベースのシグナル分子を生成する.
研究 の 目的:
- バクテリアの2型トーエリス防御システムによって生成される 独特のシグナル分子を調査する
- この新しいシグナル伝達分子の構造,機能,認識メカニズムを解明する.
主な方法:
- リガンド結合マクロドメインの結晶構造の決定.
- 機能確認のための生化学的測定と変異分析
- 信号分子と相互作用するファグタンパク質の識別
主要な成果:
- Thoerisシステムは,新しいシグナリング分子であるADP-リボース (His-ADPR) と結合したヒスティジンを生成します.
- His-ADPRはC端のマクロドメインと結合してThoerisエフェクターを活性化します.
- バクテリアの免疫を回避するためにHis-ADPRを隔離する新種のファグタンパク質が特定されました.
結論:
- バクテリアのTIRシグナル伝達はこれまで知られていたよりも多様性があります.
- ヒス-ADPRは 核酸とアミノ酸を組み合わせた 新しい免疫シグナル分子を表しています
- ファージは,細菌のTIR媒介免疫に対抗するメカニズムを進化させた.
さらに関連する動画
07:42Fluorescence Assays for the Study of Mycobacterium tuberculosis Interaction with the Immune Receptor SLAMF1
Published on: February 28, 2025
284
08:44Identification and Characterization of Immunogenic RNA Species in HDM Allergens that Modulate Eosinophilic Lung Inflammation
Published on: May 30, 2020
6.1K
関連する概念動画
01:24Adherens Junctions
4.7K
Strong contact points between adjacent cells anchor them to each other, forming tissues. Such anchoring junctions are of two types – adherens junctions and desmosomes. Adherens junctions are abundant in tissues such as epithelium and endothelium, forming a continuous zone of adhesion called the adhesion belt. In other tissues, such as heart muscle, they appear as clusters, linking the cells to produce coordinated heart muscle contraction.
Adherens Junctions are Dynamic
Adherens Junctions are Dynamic
4.7K
01:10Antibody Structure
59.6K
Overview
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
59.6K
01:31Defense Against Bacterial Pathogens
1.4K
The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
1.4K
01:28Diversity of Antigen Receptors
543
Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
543
01:09GPCRs Regulate Adenylyl Cylase Activity
5.4K
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of...
5.4K
01:24B Cell Activation and Differentiation
1.7K
The adaptive immune response, a sophisticated defense mechanism, relies on the activation and differentiation of B lymphocytes, or B cells. These processes enable our bodies to mount a tailored response against specific pathogens such as bacteria, free virus particles, toxins, and parasites.
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
1.7K