Extracellular arginine availability modulates eIF2α O-GlcNAcylation and heme oxygenase 1 translation for cellular homeostasis

Journal of Biomedical Science

Research

Hsing-Jien Kung¹  Ching Ouyang²  Yi-Chang Wang³  Yue Qi³  Xiaoli Ping³  David K. Ann⁴  Yu-Wen Hung⁴ 

[1] Cancer Center, School of Medicine, University of California, 95817, Davis, CA, USA;Department of Computational and Quantitative Medicine, Beckman Research Institute of City of Hope, 91010, Duarte, CA, USA;Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute of City of Hope, City of Hope Comprehensive Cancer Center, 91010-3000, Duarte, CA, USA;Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute of City of Hope, City of Hope Comprehensive Cancer Center, 91010-3000, Duarte, CA, USA;Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, 91010, Duarte, CA, USA;

关键词: Arginine;    O-GlcNAcylation;    Eukaryotic initiation factor 2α;    Protein translation;    Heme oxygenase 1;    Antioxidant defense;   

DOI  :  10.1186/s12929-023-00924-4

 received in 2022-11-22, accepted in 2023-05-04,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundNutrient limitations often lead to metabolic stress during cancer initiation and progression. To combat this stress, the enzyme heme oxygenase 1 (HMOX1, commonly known as HO-1) is thought to play a key role as an antioxidant. However, there is a discrepancy between the level of HO-1 mRNA and its protein, particularly in cells under stress. O-linked β-N-acetylglucosamine (O-GlcNAc) modification of proteins (O-GlcNAcylation) is a recently discovered cellular signaling mechanism that rivals phosphorylation in many proteins, including eukaryote translation initiation factors (eIFs). The mechanism by which eIF2α O-GlcNAcylation regulates translation of HO-1 during extracellular arginine shortage (ArgS) remains unclear.MethodsWe used mass spectrometry to study the relationship between O-GlcNAcylation and Arg availability in breast cancer BT-549 cells. We validated eIF2α O-GlcNAcylation through site-specific mutagenesis and azido sugar N-azidoacetylglucosamine-tetraacylated labeling. We then evaluated the effect of eIF2α O-GlcNAcylation on cell recovery, migration, accumulation of reactive oxygen species (ROS), and metabolic labeling during protein synthesis under different Arg conditions.ResultsOur research identified eIF2α, eIF2β, and eIF2γ, as key O-GlcNAcylation targets in the absence of Arg. We found that O-GlcNAcylation of eIF2α plays a crucial role in regulating antioxidant defense by suppressing the translation of the enzyme HO-1 during Arg limitation. Our study showed that O-GlcNAcylation of eIF2α at specific sites suppresses HO-1 translation despite high levels of HMOX1 transcription. We also found that eliminating eIF2α O-GlcNAcylation through site-specific mutagenesis improves cell recovery, migration, and reduces ROS accumulation by restoring HO-1 translation. However, the level of the metabolic stress effector ATF4 is not affected by eIF2α O-GlcNAcylation under these conditions.ConclusionsOverall, this study provides new insights into how ArgS fine-tunes the control of translation initiation and antioxidant defense through eIF2α O-GlcNAcylation, which has potential biological and clinical implications.

【 授权许可】

CC BY   
© The Author(s) 2023

【 图 表 】

40517_2023_256_Article_IEq114.gif

40517_2023_256_Article_IEq113.gif

Fig. 1

40517_2023_256_Article_IEq73.gif

Fig. 7

41512_2023_147_Article_IEq71.gif

40517_2023_256_Article_IEq59.gif

40517_2023_256_Article_IEq55.gif