内部微RNA前体,可以绕过Drosha处理
J Graham Ruby1, Calvin H Jan, David P Bartel
1Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA.
Nature
|June 26, 2007
概括
科学家们发现了一种新的microRNA (miRNA) 途径,使用被拆除的内子称为镜子. 这些绕过了Drosha处理,为动物的miRNA生物发生提供了替代途径.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 在RNA生物学,RNA生物学.
背景情况:
- 微RNAs (miRNAs) 是小型内源RNAs,通过抑制信使RNAs来调节基因表达.
- 规范性miRNA生物发生包括Drosha和Dicer处理miRNA前针头.
- 精确的机制和miRNA生物发生路径的进化起源是活跃研究的领域.
研究的目的:
- 为了确定微RNA生物发生的替代途径.
- 为了研究内子在miRNA生产中的作用.
- 为了探索微RNAs的进化起源.
主要方法:
- 生物信息分析以确定潜在的miRNA前体.
- 进行比较基因组学以评估进化保护.
- 识别的镜子的功能特征.
主要成果:
- 发现了"米特龙" - - 模仿前-miRNAs的被剥离的内核.
- 鉴定了Drosophila melanogaster中的14个Mirtron和Caenorhabditis elegans中的4个Mirtron.
- 进化保护的证据表明镜子的调节作用.
结论:
- 一个新的miRNA生物发生路径存在,利用被剥离的内核 (mirtrons).
- 镜子绕过了标准的Drosha-依赖的处理步骤.
- 这一途径可能代表了miRNA进化的古老机制,早于Drosha.
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...
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...
pre-mRNA Processing
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
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...
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...


