Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphia, PA, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphia, PA, USA.
Front Mol Biosci. 2016 Mar 15;3:8. doi: 10.3389/fmolb.2016.00008. eCollection 2016.
Cells have evolved a sophisticated proteostasis network to ensure that proteins acquire and retain their native structure and function. Critical components of this network include molecular chaperones and protein disaggregases, which function to prevent and reverse deleterious protein misfolding. Nevertheless, proteostasis networks have limits, which when exceeded can have fatal consequences as in various neurodegenerative disorders, including Parkinson's disease and amyotrophic lateral sclerosis. A promising strategy is to engineer proteostasis networks to counter challenges presented by specific diseases or specific proteins. Here, we review efforts to enhance the activity of individual molecular chaperones or protein disaggregases via engineering and directed evolution. Remarkably, enhanced global activity or altered substrate specificity of various molecular chaperones, including GroEL, Hsp70, ClpX, and Spy, can be achieved by minor changes in primary sequence and often a single missense mutation. Likewise, small changes in the primary sequence of Hsp104 yield potentiated protein disaggregases that reverse the aggregation and buffer toxicity of various neurodegenerative disease proteins, including α-synuclein, TDP-43, and FUS. Collectively, these advances have revealed key mechanistic and functional insights into chaperone and disaggregase biology. They also suggest that enhanced chaperones and disaggregases could have important applications in treating human disease as well as in the purification of valuable proteins in the pharmaceutical sector.
细胞已经进化出了一个复杂的蛋白质稳态网络，以确保蛋白质获得并保持其天然结构和功能。该网络的关键组成部分包括分子伴侣和蛋白解聚酶，它们的功能是防止和逆转有害的蛋白质错误折叠。然而，蛋白质稳态网络是有限的，当超过这个限制时，就会产生致命的后果，如各种神经退行性疾病，包括帕金森病和肌萎缩侧索硬化症。一种有前途的策略是设计蛋白质稳态网络来应对特定疾病或特定蛋白质所带来的挑战。在这里，我们回顾了通过工程和定向进化来增强单个分子伴侣或蛋白解聚酶活性的努力。值得注意的是，通过对一级序列进行微小的改变，通常只需一个错义突变，就可以增强各种分子伴侣（包括 GroEL、Hsp70、ClpX 和 Spy）的整体活性或改变其底物特异性。同样，Hsp104 的一级序列的微小变化也能产生增强的蛋白解聚酶，这些酶可以逆转各种神经退行性疾病蛋白（包括α-突触核蛋白、TDP-43 和 FUS）的聚集并缓冲其毒性。总的来说，这些进展揭示了伴侣蛋白和解聚酶生物学的关键机制和功能见解。它们还表明，增强的伴侣蛋白和解聚酶在治疗人类疾病以及在制药领域纯化有价值的蛋白质方面可能具有重要的应用前景。
