回收真核细胞终结后的核糖体复合体
Andrey V Pisarev1, Christopher U T Hellen, Tatyana V Pestova
1Department of Microbiology and Immunology, SUNY Downstate Medical Center, Brooklyn, NY 11203, USA.
Cell
|October 25, 2007
概括
细胞利用启动因子回收核糖体,与细菌不同. 像eIF3,eIF1,eIF1A和eIF3j这样的关键因素促进了蛋白质合成后的核糖体,mRNA和tRNA的解离.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 翻译后复合体 (post-TCs) 是由蛋白质合成后与核糖体相关的mRNA和脱糖的tRNA形成的.
- 核糖体循环对于细胞功能至关重要,涉及核糖体分裂成子单元以及mRNA和tRNA的释放.
- 细菌核糖体循环需要延长因子EF-G和核糖体循环因子 (RRF),但由于没有RRF同类,真核细胞机制仍然不清楚.
研究的目的:
- 为了研究真核细胞核糖体循环的机制.
- 为了确定参与eukaryotes中后TCs解离的因素.
主要方法:
- 使用编码四大的模型mRNA组装后TCs,其后是UAA停止编码子.
- 在体外测试以评估真核细胞启动因子在促进核糖体循环的活性.
主要成果:
- 细胞启动因子 (eIFs) eIF3,eIF1,eIF1A和eIF3子单位eIF3j可以促进细胞后TCs的回收.
- eIF3被确定为负责将终结后核糖体分裂成60S和40S子单元的主要因素.
- eIF1促进P位点tRNA的释放,而eIF3j则调解mRNA的随后解离.
结论:
- 细胞核糖体循环循环是由启动因子介导的,与细菌途径不同.
- 与eIF1,eIF1A和eIF3j一起,eIF3复合体在终结后核糖体,mRNA和tRNA的分离中发挥着至关重要的作用.
- 了解真核核糖核糖体循环循环提供了关于转化控制和细胞平衡的见解.
相关概念视频
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02:53Ribosomal RNA Synthesis
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
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01:27Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.Ribosome Structure and AssemblyRibosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within the...
01:27Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
01:27Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.Ribosome Structure and AssemblyRibosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within the...