一个重要的,高度选择性的蛋白质进口通路,由形成核的菌体编码
Chase J Morgan1, Eray Enustun1, Emily G Armbruster1
1School of Biological Sciences, Division of Molecular Biology, University of California San Diego, La Jolla, CA 92093.
概括
研究人员在奇马利病毒中发现了一种新的蛋白质进口途径,涉及一种叫做PicA (奇马利病毒A的蛋白质进口者) 的蛋白质. 这一途径对于菌体复制和理解病毒演变至关重要.
科学领域:
- 病毒学 病毒学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 蛋白质局部化对于所有生命形式的细胞功能至关重要.
- 奇马利维里科的菌体使用奇马林 (ChmA) 创建一个类似于核的区间,将病毒DNA复制从细胞质中分离出来.
- 在菌体核和宿主细胞质之间观察到选择性蛋白质分离,但基本机制尚不清楚.
研究的目的:
- 为了确定负责选择性蛋白质进口到chimallivirus核中的基因和信号.
- 为了阐明通过菌体核外贩运蛋白质的机制.
- 了解这种途径在奇马利病毒复制和进化的作用.
主要方法:
- 在菌体内核蛋白上确定特定物种的表面暴露区域.
- 一种保存的蛋白质,PicA (chimalliviruses A的蛋白质进口者) 的表征,涉及货物蛋白质贩运.
- 对一个有缺陷的货物蛋白质进行分析,该蛋白质结合了核,但没有进入核.
- 通过CRISPR干扰-ART (CRISPRi-ART) 的介导,抑制了PicA的表达.
主要成果:
- 确定了蛋白质进口途径的两个关键组成部分:菌体蛋白质表面区域和PicA.
- 一个有缺陷的货物蛋白提供了对核蛋白贩运机制的洞察力.
- 在周期早期,PicA对于奇马利病毒复制是必不可少的.
- 为蛋白质进口奇马利病毒途径提出了一种多步骤模型,涉及表面向氨基酸和PicA介导许可.
结论:
- 蛋白质进口奇马利病毒途径涉及特定的蛋白质向和PicA介导的进入.
- 这种途径的分歧表明它在菌体进化和宿主菌体相互作用中的作用.
- 皮卡是基马利病毒核进口和复制的一个关键因素.
相关概念视频
01:34Nuclear Protein Sorting
4.6K
Nuclear protein sorting is the selective trafficking of histones, polymerases, gene regulatory proteins into the nucleus and exporting RNAs and ribosomes to the cytosol. It is a tightly controlled process that regulates gene expression within a cell.
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
4.6K
01:46Nuclear Localization Signals and Import
5.7K
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...
5.7K
01:42Nuclear Export
3.6K
The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES.
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
3.6K
01:45Regulation of Nuclear Protein Sorting
2.4K
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
2.4K
01:27Protein Import into the Peroxisomes
3.5K
Cells contain membrane-bound organelles called peroxisomes that oxidize organic molecules by transferring hydrogen atoms to oxygen, producing hydrogen peroxide. Peroxisomes enzymatically convert the released hydrogen peroxide into water and oxygen.
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
3.5K
01:45Overview of Protein Sorting and Transport
11.3K
Eukaryotic cells have different membrane-bound organelles with distinct protein requirements. The process by which proteins are targeted to a specific organelle is called protein sorting.
Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation. In gated transport, folded...
Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation. In gated transport, folded...
11.3K