对A型流感病毒RNA聚合酶PB1与核进口宿主因子RanBP5结合的结构洞察力
Tomomi Uchikubo-Kamo1, Naito Ishimoto1, Haruka Umezawa1
1Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, 230-0045, Japan.
Biochemical and biophysical research communications
|November 13, 2024
概括
流感A病毒RNA聚合酶子单元通过宿主因子Ran结合蛋白5 (RanBP5) 导入细胞核. 结构分析揭示了PB1 NLS域如何与RanBP5相互作用,帮助药物发现.
科学领域:
- 病毒学 病毒学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 流感A病毒RNA聚合酶子单元 (PB1,PA,PB2) 对于病毒转录和在宿主细胞核中的复制至关重要.
- 这些子单元的核进口是病毒感染期间的关键步骤,但涉及宿主因素的潜在分子机制尚未完全理解.
- 现有的模型表明PB1和PA二元化,并由Ran结合蛋白5 (RanBP5) 进口,PB2则分别进口.
研究的目的:
- 阐明核进口流感A病毒RNA聚合酶子单元的结构基础.
- 研究Ran结合蛋白5 (RanBP5) 与PB1亚单元的核定位信号 (NLS) 域之间的相互作用.
- 确定参与RanBP5和PB1.1之间的复杂形成的关键氨基酸残留物.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定RanBP5和PB1 NLS域复合物的结构,分辨率为3.2 Å.
- 进行了生物化学分析,包括突变研究,以确定调解复杂结合的关键氨基酸位点.
主要成果:
- 冷-EM结构显示,PB1 NLS域缺乏二次结构,并在与RanBP5.5相互作用时采用"包裹"的形状.
- 生物化学数据确定了特定的氨基酸残留物,这些残留物对于RanBP5和PB1 NLS域之间的结合相互作用至关重要.
- 这些发现为病毒核进口过程中宿主-病原体相互作用提供了原子层面的见解.
结论:
- 这项研究表明,流感病毒结构部件的逐步组装机制,由核进口途径和宿主因子相互作用调节.
- 已确定RanBP5和PB1之间的相互作用接口是抗病毒药物开发的潜在目标.
- 了解这些宿主-病原体相互作用对于开发针对A型流感病毒的新疗法至关重要.
相关概念视频
Directionality of Nuclear Transport
3.2K
Ras-related nuclear protein or Ran is a small G protein that cycles between its GTP and GDP bound states. Ran specific regulators, a Ran GTPase Activating Protein or RanGAP present in the cytosol and a Ran guanine nucleotide exchange factor or RanGEF present inside the nucleus regulate GTP/GDP exchange. A high concentration of GTP inside the cells, in addition to this asymmetric distribution of Ran-specific regulators, leads to a higher RanGTP concentration inside the nucleus. This...
3.2K
Nuclear Localization Signals and Import
5.6K
Proteins targeted to the nucleus carry short stretches of amino acid sequences called the nuclear localization signal or NLS. Classical nuclear localization signals are of two types: monopartite and bipartite NLS. Monopartite classical NLS (cNLS) consists of a single cluster of 4-8 amino acids. Bipartite cNLS consists of two clusters of 2-3 amino acids and a 9-12 residue long proline-rich linker bridging the two clusters. Signal clusters are rich in positively charged amino acids such as...
5.6K
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
Eukaryotic RNA Polymerases
23.6K
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...
23.6K
Bacterial RNA Polymerase
28.9K
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
28.9K
Transcription Initiation
16.2K
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
16.2K


