由细胞mRNA的5'领导者介导的翻译的内部启动
1Department of Biochemistry, Biophysics and Genetics, University of Colorado Health Sciences Center, Denver 80262.
Nature
|September 5, 1991
概括
细胞信使RNA可以使用内部核糖体结合来启动翻译,而不仅仅是5'帽结构. 这种机制允许在病毒感染期间进行细胞mRNA翻译,当封顶依赖途径被阻塞时.
科学领域:
- 分子生物学分子生物学
- 病毒学 病毒学
- 遗传学 是一个遗传学.
背景情况:
- 细胞mRNA的翻译通常是通过卡普依赖扫描启动的.
- 皮科纳病毒mRNA缺乏5'帽结构,并利用内部核糖体结合.
- 细胞mRNA翻译可以在脊髓灰质炎病毒感染期间持续存在,尽管受到上限依赖的抑制.
研究的目的:
- 调查真核细胞mRNA中的替代翻译启动机制.
- 为了确定细胞mRNA是否可以使用内部核糖体结合.
主要方法:
- 在受脊髓灰质炎病毒感染的细胞中分析免疫球蛋白重链结合蛋白mRNA翻译.
- 结合蛋白mRNA的5'领导序列的功能性表征.
主要成果:
- 结合蛋白mRNA被转化为受脊髓灰质炎病毒感染的细胞.
- 结合蛋白mRNA的5'领导者赋予了内部核糖体结合能力.
- 这表明了一个独立于cap的翻译启动路径.
结论:
- 细胞mRNA可以利用内部核糖体结合来启动翻译.
- 这种机制在病毒感染期间为细胞mRNA翻译提供了一种手段.
- 内部核糖体结合是一种取决于帽子的翻译启动的替代方案.
相关概念视频
Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Regulated mRNA Transport
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific...
Leaky Scanning
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...
Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Regulated mRNA Transport
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific...
Translation in Prokaryotes
Prokaryote translation is a complex, highly coordinated process that converts genetic information from mRNA into functional proteins. It involves three stages: initiation, elongation, and termination, each facilitated by specific molecular components.Initiation of TranslationThe process begins with the assembly of the ribosomal subunits and initiation factors on the mRNA. In bacteria, the 30S ribosomal subunit recognizes the Shine-Dalgarno sequence in the mRNA, a conserved region upstream of...


