相关实验视频
Updated: Jun 14, 2025

07:02
An Assay for Quantifying Protein-RNA Binding in Bacteria
Published on: June 12, 2019
6.6K
单菌体蛋白从TIR和cGAS类酶中隔离信号
Dong Li1, Yu Xiao2,3, Iana Fedorova4
1State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China.
Nature
|October 31, 2024
概括
菌体使用Tad1和Tad2的Thoeris蛋白来中和细胞原体的抗菌体防御. 这些蛋白质结合和隔离信号分子,抑制基于循环寡核酸的抗菌体信号系统 (抗CBASS).
科学领域:
- 分子生物学
- 免疫学
- 微生物学
背景情况:
- Prokaryotic 抗菌体系统利用 TIR 和 cGAS 类酶产生信号分子,如 1'-3'-糖循环 ADP-ribose (1'-3'-gcADPR),循环二核酸 (CDN) 和循环三核酸 (CTN).
- 这些信号分子对于限制菌体复制至关重要,但菌体抵消这些防御的机制在很大程度上是未知的.
研究的目的:
- 调查细菌菌体如何中和 prokaryotic 抗菌体免疫系统,特别是基于周期性寡核酸的抗菌体信号系统 (抗CBASS).
- 阐明Thoeris抗防御蛋白Tad1和Tad2在抑制抗CBASS活动中的分子机制.
主要方法:
- 生物化学测试以确定Tad1和Tad2与各种循环核酸 (gcADPR,CDN,CTN) 的结合亲缘关系.
- 在体外和体内实验中评估Tad1和Tad2对抗CBASS系统的抑制活性.
- 对Tad1和Tad2进行结构分析,以了解它们的结合部位配置.
主要成果:
- 通过同时隔离多种循环核酸,Tad1和Tad2蛋白有效抑制抗CBASS活性.
- Tad1对Thoeris信号 (1'-3'-gcADPR,1'-2'-gcADPR) 和许多CBASS CDNs和CTNs具有很高的亲和力.
- Tad1具有独立的CDN/gcADPR和CTN结合位点,而Tad2也使用不同的位点结合多个循环核酸.
结论:
- Tad1和Tad2作为双作用抑制剂,代表了菌体克服宿主免疫力的新策略.
- 这些蛋白质建立了一个范式,其中菌体编码的蛋白质利用灵活的结合点来中和广泛的循环核酸信号.
- 这些发现有助于了解菌体与宿主之间的相互作用以及抗菌体防御机制的演变.
相关概念视频
Amplifying Signals via Enzymatic Cascade
8.4K
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze...
8.4K
IP3/DAG Signaling Pathway
11.9K
Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and...
11.9K
CRISPR and crRNAs
16.9K
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
16.9K
Assembly of Signaling Complexes
5.7K
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
5.7K
Directing Proteins to the Rough Endoplasmic Reticulum
7.2K
The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
7.2K
Tail-anchoring of Proteins in the ER Membrane
3.1K
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
3.1K

