这关键区别在转录和转录后基因沉默之间转录基因沉默是调节基因表达在转录级别以减少RNAsynthesis by promoter silencing while posttranscriptional gene silencing is the regulation of gene expression at translation level by sequence-specific RNA degradation.
基因沉默是通过中断或抑制基因表达来调节基因表达的过程。它关闭某些类型的基因。因此,它可以防止其相应基因的蛋白质产生。基因沉默可以在转录ortranslation。Hence, there are two types of gene silencing as transcriptional gene silencing and posttranscriptional gene silencing. Transcriptional gene silencing decreases RNA synthesis while posttranscriptional gene silencing degrades mRNA. Moreover, transcriptional gene silencing takes place in the nuclei while posttranscriptional gene silencing takes place in the cytoplasm.
CONTENTS
1。概述和关键差异
2。什么是转录基因沉默
3。什么是转录后基因沉默
4。Similarities Between Transcriptional and Posttranscriptional Gene Silencing
5。并排比较 - 转录与转录后基因沉默以表格形式沉默
6.Summary
什么是转录基因沉默?
转录基因沉默是基因沉默,通过降低RNA合成起作用。这是组蛋白修饰的结果,创造了转录机械无法访问的环境。这发生在细胞的核中。DNA甲基化对于转录基因沉默非常重要,因为启动子序列的甲基化发生在转录基因沉默过程中。编码序列的甲基化不会影响转录。但是,启动子序列的甲基化导致由于组蛋白脱乙酰化和染色质缩合而导致启动子失活。一旦启动子被沉默,它就会影响基因转录。因此,在转录基因沉默中,启动子被沉默以调节转录水平的基因表达。
什么是转录后基因沉默?
转录后基因沉默,也称为RNA沉默或RNA干扰,是一种基因沉默,通过RNA的序列特异性降解起作用。尽管该基因的转录不受影响,但由于不稳定或不可访问的mRNA,mRNA的蛋白质合成停止。转录后基因沉默是由双链RNA的故意产生引起的。双链RNA触发同源mRNA的裂解。对基因转录区域具有同源序列的小型干扰RNA指导mRNA的序列特异性降解。RNAi与靶mRNA的互补部分结合,并将其标记为降解。
转录后基因沉默有多种应用,包括基因治疗和癌症治疗。转录后基因沉默是针对入侵RNA病毒的植物中的自然防御机制之一。因此,转录后基因沉默缺陷的植物更容易受到RNA病毒感染的影响。
What are the Similarities Between Transcriptional and Posttranscriptional Gene Silencing?
- 这y are two distinct gene-silencing phenomena.
- 两种现象都可以由dsRNA诱导。
- 对于两种类型的沉默,都发现了小的RNA物种,被认为是DSRNA衰减产物。
- 这y are mechanistically related.
转录和转录后基因沉默有什么区别?
Transcriptional gene silencing is a gene silencing phenomenon which operates at the transcription level via decreased RNA synthesis. On the other hand, posttranscriptional gene silencing is a gene silencing phenomenon which occurs at translation level via sequence-specific degradation of mRNA. Thus, this is the key difference between transcriptional and posttranscriptional gene silencing.
此外,转录基因沉默发生在细胞核中,而转录后基因沉默发生在细胞质中。此外,启动子在转录基因沉默中被灭活,而启动子在转录后基因沉默中活跃。
下面的信息图表列出了转录和转录后基因沉默之间的更多差异。
摘要 - 转录与转录后基因沉默
Genes are regulated at either the transcriptional or posttranscriptional level. Transcriptional gene silencing occurs in the nuclei via promoter sequence methylation and histone modification. As a result, RNA synthesis decreases. Posttranscriptional gene silencing occurs in the cytoplasm through the cleavage of mRNA and inhibition of translation. Both phenomena are induced by dsRNA and depend on small interfering RNAs. Thus, this summarizes the difference between transcriptional and posttranscriptional gene silencing.
参考:
1。Hoffer, Paul, et al. “Posttranscriptional Gene Silencing in Nuclei.”PNAS,美国国家科学院,2011年1月4日,在这里可用。
图片提供:
1。“RNAi-simplified” – adapted from one by Matzke MA, Matzke AJM – This figure is adapted from one by Matzke MA, Matzke AJM (2004) Planting the Seeds of a New Paradigm. PLoS Biol 2(5): e133 doi:10.1371/journal.pbio.0020133.(CC由2.5)通过下议院维基梅迪亚
2.“哺乳动物中转录后基因沉默的基本机制的第1部分”由Mertmetin96 - 自己的工作(CC BY-SA 4.0)通过下议院维基梅迪亚
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