A viral Cyclin D homolog protein hijacks the metabolic stress sensor SESN2 to promote primary effusion lymphoma growth
Abstract
Metabolic pathways are typically dysregulated in cancer to support critical cellular processes. In response to metabolic disturbances, cancer cells preferentially manipulate stress sensors to enhance their adaptability. Sestrin 2 (SESN2), a highly conserved protein induced by various stressors, is implicated in this adaptation. Mutations and alterations of SESN2 are prevalent among cancer patients, suggesting a potential role in tumor progression. However, the functions and regulation of SESN2 in cancer, particularly in virus-induced cancer, remain largely unknown. In this study, we demonstrate that latent infection with Kaposi’s sarcoma–associated herpesvirus (KSHV) stabilizes and upregulates SESN2 by inhibiting its proteasomal degradation across multiple cell lines. Notably, KSHV-encoded vCyclin, a homolog of cellular Cyclin D, directly interacts with SESN2 and promotes its stabilization by recruiting the deubiquitinase OTUB1, thereby blocking SESN2 polyubiquitination and proteasomal degradation. Moreover, vCyclin- and OTUB1-mediated stabilization of SESN2 activates AMP-activated protein kinase (AMPK), which supports the survival and growth of KSHV-driven primary effusion lymphoma cells. Importantly, the lysine at residue 74 of vCyclin is crucial for its cytosolic localization, OTUB1 recruitment, and subsequent SESN2 upregulation and AMPK activation. These findings unveil a regulatory mechanism for SESN2 involving vCyclin and OTUB1, positioning them as potential therapeutic targets for diseases associated with AMPK dysregulation.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (12)
Mingjun Lin
Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, Laboratory of Animal Nutrition and Human Health, Hunan Provincial Key Laboratory of Animal Intestinal Function and Regulation, College of Life Sciences, Hunan Normal University
Guanya Li
Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, Laboratory of Animal Nutrition and Human Health, Hunan Provincial Key Laboratory of Animal Intestinal Function and Regulation, College of Life Sciences, Hunan Normal University
Xinyu Tang
Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, Laboratory of Animal Nutrition and Human Health, Hunan Provincial Key Laboratory of Animal Intestinal Function and Regulation, College of Life Sciences, Hunan Normal University
Ru Li
Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University
Yinan Li
Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, Laboratory of Animal Nutrition and Human Health, Hunan Provincial Key Laboratory of Animal Intestinal Function and Regulation, College of Life Sciences, Hunan Normal University
Lijie Wang
Zeyu Xu
State Key Laboratory of Materials Low-Carbon Recycling
Liansheng Liu
Guangzhou National Laboratory
Enguo Ju
Center for Nanomedicine, The Third Affiliated Hospital, Sun Yat-sen University
Jian Shang
Low-Dimensional Energy Materials Research Center
Shanping He
Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, Laboratory of Animal Nutrition and Human Health, Hunan Provincial Key Laboratory of Animal Intestinal Function and Regulation, College of Life Sciences, Hunan Normal University
Tingting Li