相关实验视频
Updated: Jun 28, 2025

09:05
MicroRNA-based Regulation of Picornavirus Tropism
Published on: February 6, 2017
7.5K
哺乳动物PIWI-piRNA-目标复合体揭示了广泛和高效的目标沉默特征
Zhiqing Li1,2,3,4, Zhenzhen Li2,3,4, Yuqi Zhang3,4,5
1School of Basic Medical Sciences, Fudan University, Shanghai, China.
Nature structural & molecular biology
|April 24, 2024
概括
哺乳动物PIWI相互作用RNA (piRNA) 复合体比无脊椎动物更有效地结合和分裂目标. 在piRNA种子中的特定氨酸允许更广泛的目标沉默,增强基因组防御.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
- 生物化学 生物化学
背景情况:
- 与PIWI相互作用的RNA (piRNA) 途径提供了对自私遗传元素的适应性防御,确保了基因组的完整性.
- 哺乳动物piRNA路径适应目标沉默仍然不太了解,尽管与转位子的快速共同进化.
研究的目的:
- 阐明哺乳动物中piRNA向和沉默背后的分子机制.
- 为了比较哺乳动物和无脊椎动物之间的功能和结构差异,piRNA诱导的沉默复合体 (piRISCs).
主要方法:
- 电子显微镜 (cryo-EM) 对老鼠MILI,人类HILI和海绵Ephydatia fluviatilis EfPiwi piRISCs的研究.
- 对目标结合和分离效率的功能分析.
- 在有或没有点RNA的情况下对piRISCs的结构比较.
主要成果:
- 与EfPiwi piRISC相比,老鼠的MILI和人类的HILI piRISC表现出增强的目标结合和分裂.
- 哺乳动物的piRISC具有更广泛的核酸结合通道和更容易获得的piRNA种子.
- 哺乳动物piRISC中保存的氨酸残留物放松了种子门,使种子-目标不匹配的耐受性和扩大目标识别.
结论:
- 该研究为哺乳动物piRNA向提供了分子基础,突出了用于高效沉默的结构性适应.
- 哺乳动物的piRNA机器可以在有限的piRNA剧目中实现广泛的目标沉默.
- 这些发现提供了关于宿主防御和自私的遗传元素之间的共同进化军备竞赛的见解.
相关概念视频
piRNA - Piwi-interacting RNAs
6.9K
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
6.9K
RNA Interference
26.0K
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
26.0K
Experimental RNAi
6.1K
RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the...
6.1K
siRNA - Small Interfering RNAs
16.7K
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
16.7K
MicroRNAs
3.0K
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...
3.0K
Conservation of Protein Domains Over Different Proteins
10.8K
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to...
10.8K

