Neves Ricardo Pires das, Chagoyen Mónica, Martinez-Lorente Antonio, Iñiguez Carlos, Calatrava Ana, Calabuig Juana, Iborra Francisco J
Center for Neuroscience and Cell Biology, CIBB-Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, 3004-517 Coimbra, Portugal.
IIIUC-Institute of Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal.
Antioxidants (Basel). 2023 Jun 14;12(6):1274. doi: 10.3390/antiox12061274.
Signaling and detoxification of Reactive Oxygen Species (ROS) are important patho-physiologcal processes. Despite this, we lack comprehensive information on individual cells and cellular structures and functions affected by ROS, which is essential to build quantitative models of the effects of ROS. The thiol groups from cysteines (Cys) in proteins play a major role in redox defense, signaling, and protein function. In this study, we show that the proteins in each subcellular compartment contain a characteristic Cys amount. Using a fluorescent assay for -SH in thiolate form and amino groups in proteins, we show that the thiolate content correlates with ROS sensitivity and signaling properties of each compartment. The highest absolute thiolate concentration was found in the nucleolus, followed by the nucleoplasm and cytoplasm whereas protein thiolate groups per protein showed an inverse pattern. In the nucleoplasm, protein reactive thiols concentrated in SC35 speckles, SMN, and the IBODY that accumulated oxidized RNA. Our findings have important functional consequences, and explain differential sensitivity to ROS.
活性氧（ROS）的信号传导和解毒是重要的病理生理过程。尽管如此，我们缺乏关于受ROS影响的单个细胞以及细胞结构和功能的全面信息，而这些信息对于构建ROS效应的定量模型至关重要。蛋白质中半胱氨酸（Cys）的硫醇基团在氧化还原防御、信号传导和蛋白质功能中起主要作用。在本研究中，我们表明每个亚细胞区室中的蛋白质含有特征性的Cys量。使用针对蛋白质中硫醇盐形式的-SH和氨基的荧光测定法，我们表明硫醇盐含量与每个区室的ROS敏感性和信号特性相关。在核仁中发现了最高的绝对硫醇盐浓度，其次是核质和细胞质，而每个蛋白质的蛋白质硫醇盐基团则呈现相反的模式。在核质中，蛋白质反应性硫醇集中在积累氧化RNA的SC35斑点、SMN和IBODY中。我们的发现具有重要的功能后果，并解释了对ROS的差异敏感性。
