Department of Life Sciences, Ben Gurion University of the Negev, Beersheva, 84105, Israel.
Bioessays. 2020 Mar;42(3):e1900207. doi: 10.1002/bies.201900207. Epub 2020 Jan 29.
In concert with the selective pressures affecting protein folding and function in the extreme environments in which they can exist, proteins in Archaea have evolved to present permanent molecular adaptations at the amino acid sequence level. Such adaptations may not, however, suffice when Archaea encounter transient changes in their surroundings. Post-translational modifications offer a rapid and reversible layer of adaptation for proteins to cope with such situations. Here, it is proposed that Archaea further augment their ability to survive changing growth conditions by modifying the extent, position, and, where relevant, the composition of different post-translational modifications, as a function of the environment. Support for this hypothesis comes from recent reports describing how patterns of protein glycosylation, methylation, and other post-translational modifications of archaeal proteins are altered in response to environmental change. Indeed, adjusting post-translational modifications as a means to cope with environmental variability may also hold true beyond the Archaea.
与影响蛋白质折叠和功能的选择性压力协同作用，在它们能够存在的极端环境中，古菌中的蛋白质已经进化到在氨基酸序列水平呈现永久性的分子适应性。然而，当古菌遇到周围环境的瞬时变化时，这种适应性可能还不够。翻译后修饰为蛋白质提供了一种快速且可逆的适应层，以应对这种情况。在这里，有人提出，古菌通过修饰不同翻译后修饰的程度、位置（在相关情况下）和组成，进一步增强其应对不断变化的生长条件的能力，作为环境的功能。这一假设得到了最近的一些报告的支持，这些报告描述了古菌蛋白的糖基化、甲基化和其他翻译后修饰模式如何响应环境变化而改变。事实上，作为应对环境变异性的一种手段，调整翻译后修饰可能也适用于古菌之外的生物。
