Mende Hannah, Müller Stefan
Institute of Biochemistry II, Goethe University, Medical School, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
Institute of Biochemistry II, Goethe University, Medical School, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
Matrix Biol. 2021 Jun;100-101:30-38. doi: 10.1016/j.matbio.2021.02.001. Epub 2021 Feb 5.
The nucleolus functions as the cellular hub for the initiation and early steps of ribosome biogenesis. Ribosomes are key components of the translation machinery and, accordingly, their abundance needs to be adjusted to the cellular energy status. Further, to ensure translational fidelity, the integrity and quality of ribosomes needs to be monitored under conditions of cellular stress. Stressful insults, such as nutrient, genotoxic or proteotoxic stress, interfere with ribosome biogenesis and activate a cellular response referred to as nucleolar stress. This nucleolar stress response typically affects nucleolar integrity and is intricately linked to the activation of protein quality control pathways, including (i) the ubiquitin proteasome system (UPS) and (ii) the autophagy machinery, to restore cellular proteostasis. Here we will review some key features of the nucleolar stress response with a particular focus on the role of the UPS and autophagy in this process.
核仁作为核糖体生物合成起始和早期步骤的细胞中心发挥作用。核糖体是翻译机器的关键组成部分，因此，它们的丰度需要根据细胞能量状态进行调整。此外，为确保翻译保真度，在细胞应激条件下需要监测核糖体的完整性和质量。诸如营养、基因毒性或蛋白毒性应激等应激性损伤会干扰核糖体生物合成并激活一种称为核仁应激的细胞反应。这种核仁应激反应通常会影响核仁完整性，并与蛋白质质量控 制途径的激活密切相关，这些途径包括：（i）泛素蛋白酶体系统（UPS）和（ii）自噬机制，以恢复细胞蛋白质稳态。在此，我们将回顾核仁应激反应的一些关键特征，特别关注UPS和自噬在这一过程中的作用。
