表达蛋白质的非酶性多聚基化
Hosahalli P Hemantha1, Sudhir N Bavikar, Yifat Herman-Bachinsky
1Department of Chemistry, Ben-Gurion University of the Negev , Beer Sheva 84105, Israel.
Journal of the American Chemical Society
|January 21, 2014
概括
研究人员开发了一种化学方法,将乌比奎链连接到蛋白质上,使得人们能够更好地研究乌比奎化和杜比奎化. 这种技术允许特定于位点的多基化蛋白质的产生,这对于理解细胞过程至关重要,例如蛋白质体降解.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 乌比基因化是一种关键的翻译后修饰,调节重要的细胞事件.
- 目前的研究经常使用未定的无素链,限制了对基质链接无素的深入分析.
- 通过酶方法对蛋白质 - 乌比奎丁合物的均制备具有挑战性.
研究的目的:
- 开发一种新的化学策略,用于制造特定地点的蛋白质 - 乌比奎丁结合物.
- 为了使在分子层面上研究ubiquitination和deubiquitination过程.
- 为研究在蛋白质降解中无素链长度的作用生成工具.
主要方法:
- 通过Cys残留物开发了一种化学方法,通过Cys残留物将乌比奎链与蛋白质基质共同连接起来.
- 在随后的结合中,利用了在ubiquitin C-termini上的acyl hydrazide功能.
- 组装了K48结合的无素链 (高达四-无素),并通过二硫化物和乙烯链接将它们与α-环球蛋白结合.
主要成果:
- 成功合成了特定于位点的聚基化α-球蛋白合物.
- 证明USP2酶将这些合成链裂开,类似于未锁链.
- 表明二-泛基素化α-环球蛋白经历了快速的蛋白质体降解,与单-泛基素化形式不同.
结论:
- 开发的化学方法可以轻松获得同质的,特定位置的多基化蛋白质.
- 这一进步有助于详细的分子研究ubiquitination, deubiquitination,以及ubiquitin-proteasome系统.
- 这些发现强调了在基质识别和降解中,基链长度的关键作用.
相关概念视频
Covalently Linked Protein Regulators
8.2K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
These groups modify specific amino acids in a protein....
8.2K
The Proteasome
1.6K
Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
1.6K
The Proteasome
7.8K
Eukaryotic cells can degrade proteins through several pathways. One of the most important amongst these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
7.8K
Regulated Protein Degradation
6.6K
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
6.6K
Regulation of Expression at Multiple Steps
1.4K
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the...
1.4K
The Unfolded Protein Response
5.6K
The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
5.6K


