School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Mandi, Himachal Pradesh 175005, India.
ACS Chem Neurosci. 2022 Aug 3;13(15):2281-2287. doi: 10.1021/acschemneuro.1c00860. Epub 2022 Jul 20.
A strong association between protein aggregation and human diseases (such as Alzheimer's, Parkinson's, and Huntington's disease) is well demonstrated. Misfolding and aggregation of p53, a central transcriptional mediator, has been revealed by various experimental evidence in different types of cancers. Aggregation studies focusing on different p53 domains, mostly, the central core domain and its mutants under the influence of various environmental conditions, and the p53 transactivation domain (TAD) (1-63) have been reported. However, the specific subdomains responsible for p53 aggregation are not known. p53 TADs interact with diverse cellular factors to modulate the function of p53 and elicit appropriate cellular responses under different stress conditions. In this study, the aggregation of the p53 TAD2 domain (38-61) has been studied in isolation. The aggregates were generated in vitro under acidic pH conditions after in silico scoring for amyloidogenic tendency and characterized using dye-based assays (ThT and bis-ANS fluorescence), CD spectroscopy, and microscopy (scanning electron microscoy, transmission electron microscopy, and atomic force microscopy). It was observed that p53 TAD2 forms characteristic β-sheet-rich amyloid-like fibrils. Via a reductionist approach, this study highlights the nature of p53 TAD2 domain (38-61) aggregation.
蛋白质聚集与人类疾病（如阿尔茨海默病、帕金森病和亨廷顿病）之间存在很强的关联，这一点已得到充分证实。p53 是一种重要的转录调节剂，各种实验证据表明它在不同类型的癌症中发生错误折叠和聚集。已经有研究报道了针对 p53 不同结构域（主要是中央核心结构域及其突变体）的聚集研究，这些研究受到各种环境条件的影响，以及 p53 转录激活结构域（TAD）（1-63）。然而，导致 p53 聚集的特定亚结构域尚不清楚。p53 TAD 与多种细胞因子相互作用，以调节 p53 的功能，并在不同应激条件下引发适当的细胞反应。在这项研究中，p53 TAD2 结构域（38-61）的聚集被单独研究。在计算出淀粉样倾向后，在酸性 pH 条件下进行体外模拟，使用染料基检测（ThT 和双 ANS 荧光）、圆二色性光谱学、显微镜（扫描电子显微镜、透射电子显微镜和原子力显微镜）对聚集物进行了表征。结果表明，p53 TAD2 形成了特征性富含β-折叠的类淀粉样纤维。通过简化方法，本研究强调了 p53 TAD2 结构域（38-61）聚集的性质。
