mRNA的N1-甲基伪化导致了+1的核糖体框架转移
Thomas E Mulroney1, Tuija Pöyry1, Juan Carlos Yam-Puc1
1MRC Toxicology Unit, University of Cambridge, Cambridge, UK.
Nature
|December 6, 2023
概括
修改后的mRNA疫苗,如SARS-CoV-2疫苗,可能会因N1-甲基伪氨酸而导致核糖体框架转移. 序列优化可以减少这些意外的蛋白质产物.
科学领域:
- 分子生物学
- 疫苗学
背景情况:
- 在体外转录 (IVT) 的信使RNA (mRNA) 对于治疗性蛋白质和疫苗至关重要,例如SARS-CoV-2.
- 修改后的核糖核酸被纳入IVTmRNA以减少先天免疫性,但它们对翻译忠实性的影响仍未得到充分研究.
研究的目的:
- 调查N1-甲基伪尿素在mRNA翻译效率上的影响.
- 在接种疫苗的受试者中评估观察到的翻译错误的体内相关性,特别是+1核糖体框架转移.
主要方法:
- 在体外转录mRNA与N1-甲基伪尿素.
- 在mRNA转化过程中使用in vitro测试进行核糖体框架转移的分析.
- 用BNT162b2 mRNA疫苗接种后,对老鼠和人类的细胞免疫力进行评估.
主要成果:
- 在mRNA中纳入N1-methylpseudouridine会导致在体内发生1+1的核糖体框架转移.
- 在小鼠和人类中,通过BNT162b2疫苗的mRNA转化产生的细胞免疫力.
- 在滑动序列中由N1-甲基伪尿素诱导的核糖体停滞是移的可能原因.
- 同义序列定位有效地减少了移产品的生产.
结论:
- 修改后的核糖类,特别是N1- 甲基伪尿素,可能会影响mRNA的翻译效率,导致核糖体框架转移.
- 虽然目前的mRNA SARS-CoV-2疫苗没有报告任何不良结果,但这些发现突出显示了未来mRNA疗法的潜在非目标效应.
- 序列优化对于减轻意外蛋白质产生和确保基于mRNA的疗法的安全性和有效性至关重要.
相关概念视频
Nonsense-mediated mRNA Decay
10.6K
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
10.6K
Nuclear Export of mRNA
7.7K
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...
7.7K
Leaky Scanning
5.1K
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...
5.1K
RNA Editing
9.0K
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
9.0K
RNA Stability
33.6K
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
33.6K
Translation
14.9K
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Proteins are...
Translation Produces the Building Blocks of Life
Proteins are...
14.9K


