分子陪伴者激活Drosophila ecdysone受体,这是一个RXR异构体
1Department of Developmental Biology, Stanford University School of Medicine, California 94305, USA.
Cell
|April 25, 2000
概括
类固醇激素20-hydroxyecdysone通过形成受体复合体来激活Drosophila的发育. 这种激活需要一个伴侣复合体,其中Hsp90和HSC70被确定为关键的体内成分,向ecdysone受体 (EcR).
科学领域:
- 分子生物学分子生物学
- 发展生物学 发展生物学
- 内分泌学 在内分泌学.
背景情况:
- 类固醇激素20-hydroxyecdysone可以调节虫的发育.
- 它通过ecdysone受体 (EcR) 和视网膜X受体同类物 (USP) 的异构体起作用.
- 激活RXR异构体通常不需要伴侣复合体.
研究的目的:
- 为了研究对Ecr/USPDNA结合活性的伴侣复合物的要求.
- 识别伴侣复合体内的特定蛋白质,这些蛋白质对于EcR/USP激活至关重要.
- 确定这些蛋白质的体内作用及其主要点在ecdysone受体综合体内.
主要方法:
- 从伴侣复合体中净化六个单独的蛋白质.
- 试验室试验测试纯化蛋白质对EcR/USP激活的充分性.
- 在体内研究以评估Hsp90和Hsc70对于ecdysone受体活性的必要性.
主要成果:
- EcR / USP DNA 结合活性需要由伴侣异构复合体激活.
- 六个纯化的伴侣蛋白质足以激活EcR/USP.
- 热冲击蛋白Hsp90和HSC70在体内对于ecdysone受体活性至关重要.
- 埃克迪松受体 (EcR) 是陪伴者综合体的主要目标.
结论:
- 以前与RXR异构体激活无关的Chaperone复合体,对于Drosophila的EcR/USP功能至关重要.
- 特定的伴侣蛋白,包括Hsp90和Hsc70,在调节发育过程中类固醇激素信号传递方面发挥着关键作用.
- EcR是由伴侣复合体直接调节的,突出显示了在类固醇受体激活中保留的机制.
相关概念视频
Molecular Chaperones and Protein Folding
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...
The Ratio of X Chromosome to Autosomes
In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Dosage Compensation
In animals, gender is determined by the number and type of sex chromosome. For example, human females have two X chromosomes, and males have one X and one Y chromosome, whereas C.elegans with one X chromosome is a male, and the one with two X chromosomes is a hermaphrodite.
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
Exon Recombination
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Exon shuffling follows “splice frame rules.” Each exon has three reading...
The Unfolded Protein Response
The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
Regulation of the Unfolded Protein Response
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...


