Cytoplasmic Endonuclease G promotes nonalcoholic fatty liver disease via mTORC2-AKT-ACLY and endoplasmic reticulum stress

• Published in: Nature communications Vol. 14; no. 1; pp. 6201 - 16
• Main Authors: Wang, Wenjun, Tan, Junyang, Liu, Xiaomin, Guo, Wenqi, Li, Mengmeng, Liu, Xinjie, Liu, Yanyan, Dai, Wenyu, Hu, Liubing, Wang, Yimin, Lu, Qiuxia, Lee, Wen Xing, Tang, Hong-Wen, Zhou, Qinghua
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 04.10.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 14/19; 14/34; 14/63; 38; 38/88; 38/91; 631/80/642/1463; 631/80/86/2365; 692/699/317; 82/58; 96/1; Acetyl Coenzyme A; AKT protein; Animals; Apoptosis; Apoptosis - genetics; Autophagy; Cytosol; Cytosol - metabolism; Endonuclease; Endoplasmic reticulum; Endoplasmic Reticulum Stress; Fatty liver; Female; Females; Genomes; High fat diet; Humanities and Social Sciences; Lipids; Liver; Liver diseases; Mechanistic Target of Rapamycin Complex 2; Mice; Mitochondria; multidisciplinary; Non-alcoholic Fatty Liver Disease; Proto-Oncogene Proteins c-akt - metabolism; Science; Science (multidisciplinary); Synthesis
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-41757-x

Endonuclease G (ENDOG), a nuclear-encoded mitochondrial intermembrane space protein, is well known to be translocated into the nucleus during apoptosis. Recent studies have shown that ENDOG might enter the mitochondrial matrix to regulate mitochondrial genome cleavage and replication. However, little is known about the role of ENDOG in the cytosol. Our previous work showed that cytoplasmic ENDOG competitively binds with 14-3-3γ, which released TSC2 to repress mTORC1 signaling and induce autophagy. Here, we demonstrate that cytoplasmic ENDOG could also release Rictor from 14-3-3γ to activate the mTORC2-AKT-ACLY axis, resulting in acetyl-CoA production. Importantly, we observe that ENDOG could translocate to the ER, bind with Bip, and release IRE1a/PERK to activate the endoplasmic reticulum stress response, promoting lipid synthesis. Taken together, we demonstrate that loss of ENDOG suppresses acetyl-CoA production and lipid synthesis, along with reducing endoplasmic reticulum stress, which eventually alleviates high-fat diet-induced nonalcoholic fatty liver disease in female mice. Endonuclease G is known to translocate to the nucleus during apoptosis, but less is known about its role in the cytosol. Here, the authors show that cytoplasmic endonuclease G activates mTORC2 signaling and ER stress to promote NAFLD in female mice.