let-7微RNA与Lin28的相互作用的分子基础
Yunsun Nam1, Casandra Chen, Richard I Gregory
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
Cell
|November 15, 2011
概括
林28蛋白特别通过与let-7前体结合来抑制let-7微RNA (miRNA) 的产生. 它的结构揭示了它如何识别多样化的let-7家族成员,解释了它在基因表达中的调节作用.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 微RNAs (miRNAs) 是基因表达的关键调节者.
- Let-7 miRNA家族在细胞命运,多能性,分化和转化中发挥着关键作用.
- 林28作为let-7生物发生的特定转录后抑制剂.
研究的目的:
- 为了阐明Lin28抑制let-7生物发生的分子机制.
- 确定Lin28对let-7家族成员的特异性的结构基础.
- 为Lin28在基因表达中的调节作用提供分子解释.
主要方法:
- 进行X射线晶体学以确定小鼠Lin28与let-7RNA前体复合的结构.
- 核磁共振光谱分析Lin28.28中链接器区域的灵活性.
- 在体内实验以评估Lin28的抑制功能在let-7.
主要成果:
- 晶体结构显示,Lin28的两个折叠域识别了let-7RNA前体的不同区域.
- 28结合及其结构特征足以抑制体内let-7生物发生.
- 核磁共振数据显示,连接Lin28的域的链接器是灵活的,使其能够与各种let-7家族成员结合.
- 蛋白质-RNA复合体的形成诱导了Lin28和let-7中的特定构造,可能会影响下游相互作用.
结论:
- 这项研究为Lin28在抑制let-7微RNA产生方面的特异性提供了详细的分子解释.
- 提出了一种结构模型,用于Lin28介导的let-7生物发生的调节及其对基因表达控制的影响.
相关概念视频
MicroRNAs
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 ends...
MicroRNAs
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...
MicroRNAs
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 ends...
lncRNA - Long Non-coding RNAs
In humans, more than 80% of the genome gets transcribed. However, only around 2% of the genome codes for proteins. The remaining part produces non-coding RNAs which includes ribosomal RNAs, transfer RNAs, telomerase RNAs, and regulatory RNAs, among other types. A large number of regulatory non-coding RNAs have been classified into two groups depending upon their length – small non-coding RNAs, such as microRNA, which are less than 200 nucleotides in length, and long non-coding RNA (lncRNA)...
Regulation of Expression Occurs at Multiple Steps
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
RNA Interference
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...


