Jensen Kristine Steen
Division for Biophysical Chemistry, Center for Molecular Protein Science, Department of Chemistry, Lund University, Lund, Sweden.
Protein Sci. 2025 Sep;34(9):e70267. doi: 10.1002/pro.70267.
Co- and post-translational modifications can significantly impact the structure, dynamics, and function of proteins. In this study, we investigate how N-terminal acetylation affects misfolding and self-assembly of the enzyme superoxide dismutase 1 (SOD1), implicated in amyotrophic lateral sclerosis (ALS). Studies of protein inclusions in patient samples and animal models have shown that wild-type SOD1 can form amyloid fibrils even when no mutations are found in the sod1 gene. This has identified SOD1 amyloid formation as a possible common denominator of ALS and may suggest that co- and post-translational modifications, like N-terminal acetylation found in human SOD1, can be a factor in disease development. In this work, the impact of N-terminal acetylation of SOD1 on stability and aggregation is characterized. Results show that the structure and thermal stability of the apo state are unaffected by the modification while the amyloid formation rate is significantly enhanced. This is caused by a shortening of the nucleation phase together with an increase of fibril elongation by more than 10-fold upon N-terminal acetylation of SOD1. Collectively, the findings demonstrate how regulation by co- and post-translational modifications can influence protein misfolding and self-assembly.
共翻译后修饰和翻译后修饰会显著影响蛋白质的结构、动力学和功能。在本研究中,我们探究了N端乙酰化如何影响与肌萎缩侧索硬化症(ALS)相关的超氧化物歧化酶1(SOD1)的错误折叠和自组装。对患者样本和动物模型中蛋白质包涵体的研究表明,即使在sod1基因中未发现突变,野生型SOD1也能形成淀粉样纤维。这已将SOD1淀粉样蛋白形成确定为ALS可能的共同特征,并可能表明共翻译后修饰和翻译后修饰,如在人SOD1中发现的N端乙酰化,可能是疾病发展的一个因素。在这项工作中,对SOD1的N端乙酰化对稳定性和聚集的影响进行了表征。结果表明,脱辅基状态的结构和热稳定性不受该修饰的影响,而淀粉样蛋白形成速率显著提高。这是由于SOD1的N端乙酰化后成核阶段缩短以及纤维伸长增加了10倍以上所致。总的来说,这些发现证明了共翻译后修饰和翻译后修饰的调控如何影响蛋白质的错误折叠和自组装。