Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
Cell Rep. 2018 Aug 7;24(6):1415-1424. doi: 10.1016/j.celrep.2018.07.021.
Nutrient deprivation inhibits mRNA translation through mTOR and eIF2α signaling, but it is unclear how the translational program is controlled to reflect the degree of a metabolic stress. In a model of breast cellular transformation, various forms of nutrient deprivation differentially affect the rate of protein synthesis and its recovery over time. Genome-wide translational profiling of glutamine-deprived cells reveals a rapid upregulation of mRNAs containing uORFs and downregulation of ribosomal protein mRNAs, which are followed by selective translation of cytokine and inflammatory mRNAs. Transcription and translation of inflammatory and cytokine genes are stimulated in response to diverse metabolic stresses and depend on eIF2α phosphorylation, with the extent of stimulation correlating with the decrease in global protein synthesis. In accord with the inflammatory stimulus, glutamine deprivation stimulates the migration of transformed cells. Thus, pro-inflammatory gene expression is coupled to metabolic stress, and this can affect cancer cell behavior upon nutrient limitation.
营养剥夺通过 mTOR 和 eIF2α 信号抑制 mRNA 翻译,但尚不清楚如何控制翻译程序以反映代谢应激的程度。在乳腺细胞转化模型中,各种形式的营养剥夺会对蛋白质合成的速度及其随时间的恢复产生不同的影响。对谷氨酰胺剥夺细胞的全基因组翻译谱分析显示,含有 uORF 的 mRNAs 迅速上调,核糖体蛋白 mRNAs 下调,随后细胞因子和炎症 mRNAs 被选择性翻译。炎症和细胞因子基因的转录和翻译会被多种代谢应激刺激,这依赖于 eIF2α 的磷酸化,刺激的程度与整体蛋白质合成的减少相关。与炎症刺激一致,谷氨酰胺剥夺会刺激转化细胞的迁移。因此,促炎基因的表达与代谢应激相关,这可能会影响营养限制下的癌细胞行为。