Puri Sarita, Chen Szu-Ni, Chiu Yi-Hsiang, Draczkowski Piotr, Ko Kuang-Ting, Yang Tzu-Jing, Wang Yong-Sheng, Uchiyama Susumu, Hsu Shang-Te Danny
Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan. Electronic address: https://twitter.com/Saritapuri1504.
Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan.
J Mol Biol. 2022 May 15;434(9):167553. doi: 10.1016/j.jmb.2022.167553. Epub 2022 Mar 19.
BRAC1 associated protein-1 (BAP1) is a major tumor suppressor involved in many cancers. The deubiquitinase (DUB) activity of BAP1 is essential for its nuclear localization, histone remodeling and proteostasis associated with mitochondrial calcium flux. Loss of the DUB activity due to catalytic mutations within the ubiquitin C-terminal hydrolase (UCH) domain of BAP1 (BAP1-UCH) directly contributes to oncogenesis. Nevertheless, it is non-trivial to rationalize how the other high-frequency but non-catalytic mutations within the BAP1-UCH lead to malignancies. Here we used multiplex spectroscopic, thermodynamic and biophysical analyses to investigate the impacts of eleven high-occurrence mutations within BAP1-UCH on the structure, folding and function. Several mutations significantly destabilize BAP1-UCH and increase its aggregation propensity. Hydrogen-deuterium exchange mass spectrometry data revealed allosteric destabilizations caused by mutations distant from the catalytic site. Our findings gave a comprehensive and multiscale account of the molecular basis of how these non-catalytic mutations within BAP1-UCH may be implicated in oncogenesis.
乳腺癌1号基因相关蛋白1（BAP1）是一种参与多种癌症的主要肿瘤抑制因子。BAP1的去泛素化酶（DUB）活性对其核定位、组蛋白重塑以及与线粒体钙通量相关的蛋白质稳态至关重要。由于BAP1泛素C末端水解酶（UCH）结构域内的催化突变导致DUB活性丧失（BAP1-UCH）直接促成肿瘤发生。然而，要阐明BAP1-UCH内其他高频但非催化性突变如何导致恶性肿瘤并非易事。在此，我们运用多重光谱、热力学和生物物理分析方法，研究BAP1-UCH内11个高发性突变对其结构、折叠和功能的影响。几个突变显著破坏BAP1-UCH的稳定性并增加其聚集倾向。氢氘交换质谱数据揭示了远离催化位点的突变引起的变构失稳。我们的研究结果全面且多尺度地阐述了BAP1-UCH内这些非催化性突变可能与肿瘤发生相关的分子基础。
