在TLR/IL-1R信号系统中的MyD88-IRAK4-IRAK2复合体中的螺旋组件
Su-Chang Lin1, Yu-Chih Lo, Hao Wu
1Department of Biochemistry, Weill Cornell Medical College, New York, New York 10021, USA.
Nature
|May 21, 2010
概括
MyD88-IRAK4-IRAK2死亡域复合体形成了一个独特的螺旋结构,揭示了如何启动Toll-like受体信号. 这一发现澄清了关键信号通路的组装和调节.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 免疫学 免疫学 免疫学
背景情况:
- 骨髓分化的初级响应88 (MyD88),介素-1受体关联激酶4 (IRAK4) 和IRAK2是关键的信号传导媒介.
- 这些蛋白质是toll/interleukin-1受体 (TLR/IL-1R) 超级家族的一部分,对天生的免疫非常重要.
研究的目的:
- 为了确定MyD88-IRAK4-IRAK2死亡域 (DD) 综合体的晶体结构.
- 阐明Myddosome复合体的组装机制和调节原则.
主要方法:
- 进行X射线晶体学以确定该综合体的结构.
- 致变性研究以证实结合部位和功能作用.
- 对先前发现的信号突变进行分析.
主要成果:
- 晶体结构显示出一个由6个MyD88,4个IRAK4和4个IRAK2死亡域组成的左手螺旋寡合体.
- 观察到一个层次的组合:MyD88招募了IRAK4,后者又招募了IRAK2或IRAK1.
- 复合材料的结合点和静电互补性决定了复合物的特异性和稳定性.
- 中基因组形成将IRAK激酶域聚集在一起进行激活.
结论:
- MyD88-IRAK4-IRAK2复合体形成了一个"信号塔",对于TLR/IL-1R通路激活至关重要.
- 这种结构为Drosophila中的Toll信号提供了一个模板,并突出了死亡域复合体的多功能调节.
相关概念视频
NF-κB-dependent Signaling Pathway
The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...
Assembly of Signaling Complexes
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,...
MAPK Signaling Cascades
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
The JAK-STAT Signaling Pathway
Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2...
TGF - β Signaling Pathway
The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
T Cell Types and Functions
When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...


