增强的Hsp104变体对抗各种蛋白质毒性错折事件
Meredith E Jackrel1, Morgan E DeSantis2, Bryan A Martinez3
1Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
Cell
|January 21, 2014
概括
科学家们重新编程了酵母Hsp104以创建强大的变体,可以溶解涉及ALS和帕金森等神经退行性疾病的有毒蛋白质聚合物. 这些增强的分聚酶可以恢复蛋白质静止,并减轻神经退行.
科学领域:
- 神经生物学 神经生物学 神经生物学
- 分子生物学分子生物学
- 蛋白质化学 蛋白质化学
背景情况:
- 致命的神经退行性疾病,如ALS和帕金森缺乏治疗方法来逆转蛋白质毒性蛋白质错误折叠.
- 酵母Hsp104分聚酶可以溶解聚合物,但对人类疾病蛋白质的有效性有限,并且没有metazoan同类.
研究的目的:
- 设计具有针对人类疾病相关蛋白质聚合物的增强活性的Hsp104变体.
- 研究Hsp104变种抑制蛋白质毒性和神经退行症的机制.
主要方法:
- 在特定域 (中域螺旋1,2或3;核酸结合域1小域) 进行Hsp104的位点定向突变发生.
- 在细胞模型中进行聚合物溶解,蛋白质定位,蛋白质毒性抑制的测试.
- 在Caenorhabditis elegans帕金森病模型中测试疗效.
主要成果:
- 在Hsp104中单残留突变产生了有效挽救TDP-43,FUS和α-synuclein蛋白毒性的变异.
- 增强的Hsp104变种增强了聚合物溶解,恢复了蛋白质局部化,并抑制了蛋白质毒性.
- 在C. elegans帕金森病模型中,HSP104变异减弱了多巴胺能神经退行.
- 突变改善了Hsp104的活动,消除了Hsp70的依赖性,并增强了ATPase和unfoldase功能.
结论:
- 与疾病相关的蛋白质聚合物是可处理的治疗点.
- 工程化Hsp104分解酶可以恢复蛋白质静止并减轻神经退行.
- Hsp104重编程为治疗蛋白质错折疾病提供了一个有希望的策略.
相关概念视频
Molecular Chaperones and Protein Folding
14.7K
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...
14.7K
Export of Misfolded Proteins out of the ER
4.3K
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
4.3K
Amyloid Fibrils
10.2K
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining,...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining,...
10.2K
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
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


