Project description:The adaptation of tumor cells to metabolic stress is crucial for tumor development. We demonstrate that the translation of NRF2, a master regulator of antioxidant response, is controlled by the OGDH-METTL3 axis in melanoma for glucose starvation adaptation. To elucidate the regulatory mechanism of the OGDH-METTL3 axis during glucose starvation, we conducted co-immunoprecipitation and mass spectrometry analysis to identify the binding partner of OGDH that governs both the OGDH-METTL3 axis and tumor cell adaptation to glucose deprivation.
Project description:A universal feature of the response to stress and nutrient limitation is transcriptional upregulation of genes encoding proteins important for survival. Interestingly, under many of these conditions overall protein synthesis levels are reduced, thereby dampening the stress response at the level of protein expression. For example, during glucose starvation in yeast, translation is rapidly and reversibly repressed, yet transcription of many stress- and glucose-repressed genes is increased. Using ribosome profiling and microscopy, we found that this transcriptionally upregulated gene set consists of two classes: (1) one producing mRNAs that are preferentially translated during glucose limitation and are diffusely localized in the cytoplasm – this class includes many heat shock protein mRNAs; and (2) another producing mRNAs that are poorly translated during glucose limitation, have high rates of translation initiation, and are concentrated in foci that co-localize with P bodies and stress granules – this class is enriched for glucose metabolism mRNAs. Remarkably, the information specifying differential localization and translation of these two classes of mRNAs is encoded in the promoter sequence – promoter responsiveness to heat shock factor (Hsf1) specifies diffuse cytoplasmic localization and preferential translation upon glucose starvation, whereas different promoter elements upstream of genes encoding poorly translated glucose metabolism mRNAs direct these mRNAs to RNA granules under glucose starvation. Thus, promoter sequences and transcription factor binding can influence not only mRNA levels, but also subcellular localization of mRNAs and the efficiency with which they are translated, enabling cells to tailor protein production to environmental conditions. Examination of mRNA translation in S. cerevisiae upon glucose starvation.
Project description:A universal feature of the response to stress and nutrient limitation is transcriptional upregulation of genes encoding proteins important for survival. Interestingly, under many of these conditions overall protein synthesis levels are reduced, thereby dampening the stress response at the level of protein expression. For example, during glucose starvation in yeast, translation is rapidly and reversibly repressed, yet transcription of many stress- and glucose-repressed genes is increased. Using ribosome profiling and microscopy, we found that this transcriptionally upregulated gene set consists of two classes: (1) one producing mRNAs that are preferentially translated during glucose limitation and are diffusely localized in the cytoplasm – this class includes many heat shock protein mRNAs; and (2) another producing mRNAs that are poorly translated during glucose limitation, have high rates of translation initiation, and are concentrated in foci that co-localize with P bodies and stress granules – this class is enriched for glucose metabolism mRNAs. Remarkably, the information specifying differential localization and translation of these two classes of mRNAs is encoded in the promoter sequence – promoter responsiveness to heat shock factor (Hsf1) specifies diffuse cytoplasmic localization and preferential translation upon glucose starvation, whereas different promoter elements upstream of genes encoding poorly translated glucose metabolism mRNAs direct these mRNAs to RNA granules under glucose starvation. Thus, promoter sequences and transcription factor binding can influence not only mRNA levels, but also subcellular localization of mRNAs and the efficiency with which they are translated, enabling cells to tailor protein production to environmental conditions.
Project description:Ribosome profiling provides an opportunity to not only assess how the relative abundance of ribosome association with mRNAs changes in different conditions, but to look more closely at where along mRNAs those ribosomes bind. Here, we used ribosome profiling to calculate the ribosome polarity scores and changes in ribosome footprint read density in both aggregate and gene-specific ways. We profiled a time course of acute glucose starvation followed by glucose readdition and a multi-day growth course through the diauxic shift into stationary phase. We found that ribosome polarity became positive in postdiauxic shift conditions relative to log phase. In acute starvation, polarity shifted positive at our earliest time points but did not continue to do so at later time points. This is consistent with a read density analysis which demonstrated increased density on the 3’ half of genes after glucose starvation. Additionally, we performed ribosome profiling in samples that had glucose added back following acute starvation and observed a wave of new ribosome movement near the start codon and approximately 2,000 nucleotides downstream on open reading frames after one and five minutes of readdition, respectively. Our ribosome profiling analysis suggested that elongation slows during starvation which leads to a buildup of ribosomes on the 3’ halves of mRNAs. Further, it also indicated ribosomes previously built up can resume translation upon glucose readdition. We used reporter assays to corroborate these findings in vivo. Together, these results demonstrate how yeast regulate translation in response to glucose starvation.
Project description:The role of H2A monoubiquitination at K119 in regulating gene expression and cellular function upon glucose deprivation is unknown. Here, we conducted ChIP-seq for UMRC6 cells cultured with or without glucose for 8 hours using primary antibody against H2Aub. Genes with deregulated H2Aub level under glucose starvation condition were particular of interest.
Project description:Proteome data obtained with timsTOF Pro of the fission yeast cells exposed to glucose starvation at four time points 0 (glucose rich conditions), 15, 60 and 120 minutes
Project description:To determine which genes are affected by methylated Pontin, we performed RNA-sequencing (RNA-seq) in Pontin WT and RA MEFs after glucose starvation.
Project description:"Starving cancer to death" is pursued for cancer therapy. An intriguing regime is to inhibit glucose transporter GLUT1 in cancer cells. But past attempts are challenged by that cancer cells can somehow tolerate starvation. In addition, during cancer progression, cancer cells may suffer from insufficient nutrient supply, for example due to insufficient angiogenesis. So uncovering mechanism of starvation resistance shall not only shed insight into cancer progression but also benefit cancer therapy. TFE3 is known as a transcription factor capable of activating autophagic genes. Physiological TFE3 activity is regulated by phosphorylation-triggered translocation, which is sensitive to nutrient status. We recently reported TFE3 constitutively localizes to cell nucleus in kidney cancer, promoting cell proliferation even under replete condition. But whether and how TFE3 affects kidney cancer cell sensitivity to starvation is unclear. In this study, we find TFE3 promotes kidney cancer cell resistance to glucose starvation. We show starvation triggers TFE3 protein stabilization through increasing its O-GlcNAcylation. Furthermore, through unbiased functional genomic study, we identify genes sensitive to TFE3 protein level, including SLC36A1, a lysosomal amino acid transporter. We find SLC36A1 is overexpressed in kidney cancer, promotes mTOR activity and kidney cancer cell proliferation. Importantly, SLC36A1 level is directly upregulated by TFE3 upon starvation, which enhances cellular resistance to starvation. Suppressing TFE3 or SLC36A1 significantly increased cellular sensitivity to GLUT1 inhibitor in kidney cancers. Collectively, we uncover a TFE3-SLC36A1 axis that responds to starvation and enhances starvation tolerance in kidney cancer.
Project description:This data set consists of a long term glucose starvation time course of E. coli grown in minimal media for up to two weeks. Unlike previous studies of long term starvation,Our study focuses on the physiological response of E. Coli in stationary phase as a result of being starved for glucose, not on the genetic adaptation of E. coli to utilize alternative nutrients.