The mTOR-S6K pathway links growth signalling to DNA damage response by targeting RNF168

• Published in: Nature cell biology Vol. 20; no. 3; pp. 320 - 331
• Main Authors: Xie, Xiaoduo, Hu, Hongli, Tong, Xinyuan, Li, Long, Liu, Xiangyuan, Chen, Min, Yuan, Huairui, Xie, Xia, Li, Qingrun, Zhang, Yuxue, Ouyang, Huafang, Wei, Mengqi, Huang, Jing, Liu, Pengda, Gan, Wenjian, Liu, Yong, Xie, Anyong, Kuai, Xiaoling, Chirn, Gung-Wei, Zhou, Hu, Zeng, Rong, Hu, Ronggui, Qin, Jun, Meng, Fei-Long, Wei, Wenyi, Ji, Hongbin, Gao, Daming
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.03.2018
• Subjects: A549 Cells; Animals; Cell Proliferation; Control stability; Damage accumulation; Defects; Deoxyribonucleic acid; DNA; DNA Breaks, Double-Stranded; DNA damage; DNA Repair; Female; Gene expression; Genomes; Genomic instability; Growth factors; HCT116 Cells; HEK293 Cells; Humans; Liver; LKB1 protein; Male; Mechanistic Target of Rapamycin Complex 1 - genetics; Mechanistic Target of Rapamycin Complex 1 - metabolism; Mice; Mice, Inbred BALB C; Mice, Nude; Mice, Transgenic; Neoplasms - enzymology; Neoplasms - genetics; Neoplasms - pathology; Nutrients; Phosphorylation; Protein-Serine-Threonine Kinases - genetics; Protein-Serine-Threonine Kinases - metabolism; Proteolysis; Rapamycin; Ribosomal protein S6 kinase; Ribosomal Protein S6 Kinases, 70-kDa - genetics; Ribosomal Protein S6 Kinases, 70-kDa - metabolism; Ribosomal Protein S6 Kinases, 90-kDa - genetics; Ribosomal Protein S6 Kinases, 90-kDa - metabolism; Signal Transduction; Signaling; Stability; TOR protein; TOR Serine-Threonine Kinases - genetics; TOR Serine-Threonine Kinases - metabolism; Tumor Burden; Tumorigenesis; Tumors; Ubiquitin-protein ligase; Ubiquitin-Protein Ligases - genetics; Ubiquitin-Protein Ligases - metabolism
• ISSN: 1465-7392; 1476-4679
• DOI: 10.1038/s41556-017-0033-8

Growth signals, such as extracellular nutrients and growth factors, have substantial effects on genome integrity; however, the direct underlying link remains unclear. Here, we show that the mechanistic target of rapamycin (mTOR)-ribosomal S6 kinase (S6K) pathway, a central regulator of growth signalling, phosphorylates RNF168 at Ser60 to inhibit its E3 ligase activity, accelerate its proteolysis and impair its function in the DNA damage response, leading to accumulated unrepaired DNA and genome instability. Moreover, loss of the tumour suppressor liver kinase B1 (LKB1; also known as STK11) hyperactivates mTOR complex 1 (mTORC1)-S6K signalling and decreases RNF168 expression, resulting in defects in the DNA damage response. Expression of a phospho-deficient RNF168-S60A mutant rescues the DNA damage repair defects and suppresses tumorigenesis caused by Lkb1 loss. These results reveal an important function of mTORC1-S6K signalling in the DNA damage response and suggest a general mechanism that connects cell growth signalling to genome stability control.