Sun Yue, Yang Yan-Ming, Hu Yu-Yu, Ouyang Lan, Sun Zheng-Hua, Yin Xing-Feng, Li Nan, He Qing-Yu, Wang Yang
MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.
MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.
Redox Biol. 2022 Jul;53:102334. doi: 10.1016/j.redox.2022.102334. Epub 2022 May 19.
Sirtuin-1 (SIRT1) is a critical nuclear deacetylase that participates in a wide range of biological processes. We hereby employed quantitative acetyl-proteomics to globally reveal the landscape of SIRT1-dependent acetylation in colorectal cancer (CRC) cells stimulated by specific SIRT1 inhibitor Inauhzin (INZ). We strikingly observed that SIRT1 inhibition enhances protein acetylation levels, with the multisite-acetylated proteins (acetyl sites >4/protein) mainly enriched in mitochondria. INZ treatment increases mitochondrial fission and depolarization in CRC cells. The acetylation of mitochondrial proteins promoted by SIRT1 inhibition prevents the recruitment of ubiquitin and LC3 for mitophagic degradation. We then found that, SIRT1 inhibition increases the acetylation of mitochondrial calcium uniporter (MCU) at residue K332, resulting in mitochondrial Ca overload and depolarization, and ultimately CRC apoptosis. Arginine substitution of the K332 (K332R) dramatically decreases the mitochondrial Ca influx, mitochondrial membrane potential loss and ROS burst induced by INZ. This finding uncovers a non-canonical role of SIRT1 in regulating mitochondrial function and implicates a possible way for anticancer intervention through SIRT1 inhibition.
沉默调节蛋白1（SIRT1）是一种关键的核去乙酰化酶，参与广泛的生物学过程。我们在此采用定量乙酰化蛋白质组学，全面揭示了在由特异性SIRT1抑制剂Inauhzin（INZ）刺激的结肠直肠癌（CRC）细胞中，依赖SIRT1的乙酰化图谱。我们惊人地观察到，SIRT1抑制会提高蛋白质乙酰化水平，多位点乙酰化蛋白（乙酰化位点>4/蛋白）主要富集在线粒体中。INZ处理会增加CRC细胞中的线粒体分裂和去极化。SIRT1抑制所促进的线粒体蛋白乙酰化会阻止泛素和LC3的募集以进行线粒体自噬降解。然后我们发现，SIRT1抑制会增加线粒体钙单向转运体（MCU）在K332位点的乙酰化，导致线粒体钙超载和去极化，并最终导致CRC细胞凋亡。将K332位点的精氨酸替换为丙氨酸（K332R）可显著降低INZ诱导的线粒体钙内流、线粒体膜电位丧失和活性氧爆发。这一发现揭示了SIRT1在调节线粒体功能中的非经典作用，并暗示了通过抑制SIRT1进行抗癌干预的一种可能途径。
