Department of Biology, University of Rome 'Tor Vergata', Via della Ricerca Scientifica, I-00133 Rome, Italy.
Institute of Cytology, 194064 Saint-Petersburg, Russia.
Biol Chem. 2019 Jan 28;400(2):125-140. doi: 10.1515/hsz-2018-0217.
The maintenance of protein homeostasis (proteostasis) is a fundamental aspect of cell physiology that is essential for the survival of organisms under a variety of environmental and/or intracellular stress conditions. Acute and/or persistent stress exceeding the capacity of the intracellular homeostatic systems results in protein aggregation and/or damaged organelles that leads to pathological cellular states often resulting in cell death. These events are continuously suppressed by a complex macromolecular machinery that uses different intracellular pathways to maintain the proteome integrity in the various subcellular compartments ensuring a healthy cellular life span. Recent findings have highlighted the role of the multifunctional enzyme type 2 transglutaminase (TG2) as a key player in the regulation of intracellular pathways, such as autophagy/mitophagy, exosomes formation and chaperones function, which form the basis of proteostasis regulation under conditions of cellular stress. Here, we review the role of TG2 in these stress response pathways and how its various enzymatic activities might contributes to the proteostasis control.
蛋白质平衡（蛋白质稳态）的维持是细胞生理学的一个基本方面，对于生物体在各种环境和/或细胞内应激条件下的生存是必不可少的。急性和/或持续的应激超过细胞内稳态系统的能力会导致蛋白质聚集和/或受损的细胞器，导致病理细胞状态，通常导致细胞死亡。这些事件被一种复杂的大分子机制不断抑制，该机制使用不同的细胞内途径来维持各种亚细胞区室中的蛋白质组完整性，以确保健康的细胞寿命。最近的研究结果强调了多功能酶类 2 型转谷氨酰胺酶 (TG2) 在调节细胞内途径（如自噬/线粒体自噬、外泌体形成和伴侣蛋白功能）中的关键作用，这些途径是细胞应激下蛋白质稳态调节的基础。在这里，我们回顾了 TG2 在这些应激反应途径中的作用，以及其各种酶活性如何有助于蛋白质稳态的控制。
