通过甲基受体识别细菌配体的动态进化
Nicole M Paterson1,2, Hussein Al-Zubieri1, Joseph Ragona3
1Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA.
Genome biology and evolution
|September 30, 2023
概括
甲基受体 (FPR) 对于检测病原体至关重要. 在FPRs的基因进化影响动物如何识别微生物,特定的变化调整对细菌连接体的反应.
科学领域:
- 免疫学 免疫学 免疫学
- 进化生物学 进化生物学
- 基因组学就是基因组学.
背景情况:
- 细胞表面受体,如甲基受体 (FPRs),对于对病原体的先天免疫防御至关重要.
- FPRs识别微生物分子,启动炎症反应和白细胞迁移到感染部位.
- 免疫受体基因进化推动了多样化,但差异的功能影响在很大程度上是未知的.
研究的目的:
- 研究灵长类动物和食肉动物中FPRs的基因损失,多样化和连接体识别模式.
- 确定FPR分歧对与细菌连接体相互作用的功能后果.
- 了解自然选择如何在对各种微生物分子的反应中塑造FPR激活.
主要方法:
- 比较基因组学分析FPR基因损失和灵长类动物和食肉动物的多样化.
- 氨基酸变异分析以确定FPR1和FPR2.2中正选择下的区域.
- 带结合试验用于测量灵长类FPRs与细菌蛋白质 (金黄色葡萄球菌肠毒素B和FLIPr类) 之间的相互作用.
主要成果:
- 在人类免疫系统中必不可少的FPR1已经在新世界灵长类动物中消失.
- 灵长类动物和食肉动物FPR1和FPR2中的氨基酸变异表明在联结域上存在正选择.
- 灵长类FPRs中快速进化的部位显著改变了对细菌蛋白质的识别,包括激动剂和抑制剂.
结论:
- 包括遗失和多样化在内的FPR基因进化影响物种间的先天免疫识别.
- 在FPR细胞外域上的积极选择微调了对微生物配体的反应.
- 即使是FPR的微小序列变化也可以调节与细菌分子的相互作用,突出显示进化的适应性.
相关概念视频
01:19Formation of Lipopolysaccharides
34
Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin,...
34
01:26Bacterial Protein Maturation
33
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
33
01:29Coordination of Gene Expression Processes in Bacteria
37
The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...
37
01:27Chemotaxis in E. coli
34
Chemotaxis in Escherichia coli is a sensory-driven motility mechanism that enables bacteria to navigate chemical gradients, moving toward beneficial environments while avoiding harmful conditions. This process relies on a signal transduction system integrating external chemical cues with flagellar motor control.Chemoreceptors and Signal DetectionE. coli detects chemical gradients through methyl-accepting chemotaxis proteins (MCPs), which are membrane-bound chemoreceptors that sense attractants...
34
01:23Stringent Response in E. coli
28
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
28
01:28Global Regulatory Systems
41
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
41