在细胞核和细胞质之间转移前mRNA结合蛋白
1Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, Philadelphia 19104-6148.
Nature
|February 20, 1992
概括
丰富的异质核核核糖核蛋白 (hnRNP) 蛋白质,如A1,在核和细胞质之间穿. 这些hNRNP在细胞质中结合信使RNA (mRNA),影响其运输和潜在的细胞质功能.
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:
- 使者RNA (mRNA) 生物发生涉及异质核RNA (hnRNAs) 与核中的hNRNP蛋白和snRNP结合在一起.
- 传统上, hnRNP 蛋白被认为仅限于 mRNA 处理中的核功能.
- 一个拟议的模型表明,在核-细胞质mRNA运输过程中,hNRNP蛋白质被交换为mRNA结合蛋白.
研究的目的:
- 为了研究hnrp蛋白在核之外的定位和功能.
- 为了确定hnRNP蛋白是否参与细胞质mRNA处理或运输.
主要方法:
- 免疫光或生物化学测试以追踪 hnRNP 蛋白质定位.
- 在核和细胞质两部分对mRNA-蛋白质复合物的分析.
- 研究RNA聚合酶II转录在hNRNP蛋白重新进入核中的作用.
主要成果:
- 发现包括A1在内的几种丰富的hNRNP蛋白在核和细胞质之间穿.
- 细胞质 hnRNP 蛋白,特别是 A1,被观察到与mRNA结合.
- 确定RNA聚合酶II转录是A1返回核的先决条件.
结论:
- hnRNP蛋白在细胞质中具有功能性作用,不仅限于核mRNA生物发生.
- 拟议将mRNA与hNRP蛋白的细胞质核核核蛋白质复合体作为核-细胞质mRNA传输的基质.
- 这一发现重新定义了对mRNA传输和hnrp蛋白的功能表的理解.
相关概念视频
02:01pre-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...
02:01Pre-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...
02:31Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
02:22Regulated 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...
02:31Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
02:22Regulated 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...