Similar Datasets
Project description:MAF1 is a nutrient-sensitive, TORC1-regulated repressor of RNA polymerase III (Pol III). MAF1 downregulation leads to increased lipogenesis in Drosophila melanogaster, Caenorhabditis elegans, and mice. However, Maf1 -/- mice are lean as increased lipogenesis is counterbalanced by futile pre-tRNA synthesis and degradation, resulting in increased energy expenditure. We compared Chow-fed Maf1 -/- mice with Chow- or High Fat (HF)-fed Maf1 hep-/- mice that lack MAF1 specifically in hepatocytes. Unlike Maf1 -/- mice, Maf1 hep-/- mice become heavier and fattier than control mice with old age and much earlier under a HF diet. Liver ChIPseq, RNAseq and proteomics analyses indicate increased Pol III occupancy at Pol III genes, very few differences in mRNA accumulation, and protein accumulation changes consistent with increased lipogenesis. Futile pre-tRNA synthesis and degradation in the liver, as likely occurs in Maf1 hep-/- mice, thus seems insufficient to counteract increased lipogenesis. Indeed, RNAseq and metabolite profiling indicate that liver phenotypes of Maf1 -/- mice are strongly influenced by systemic inter-organ communication. Among common changes in the three phenotypically distinct cohorts, Angiogenin downregulation is likely linked to increased Pol III occupancy of tRNA genes in the Angiogenin promoter.
| S-EPMC10746880 | biostudies-literature
Project description:The conserved phosphoprotein MAF1 is the main known direct repressor of RNA polymerase III (Pol III). MAF1 is phosphorylated and inactivated by the nutrient-sensing TORC1 kinase, making MAF1 a nutrient effector for Pol III transcription. MAF1 has been associated with lipid metabolism in D. melanogaster, C. elegans, and the mouse. However, whereas downregulation of Maf1 generally increases lipogenesis, Maf1-/- mice are lean even under a High Fat (HF) diet. Here we compared Maf1-/- mice fed a Chow diet with mice lacking Maf1 specifically in hepatocytes (Maf1hep-/- mice) fed either a Chow or HF diet. Unlike Maf1-/- mice, Maf1hep-/- mice become slightly heavier than control mice at an old age and much earlier under a HF diet, with increased adiposity. Liver ChIPseq, RNAseq and proteomics analyses indicate increased Pol III occupancy at Pol III genes, very few differences in mRNA accumulation, and subtle changes in protein accumulation that are consistent with increased lipogenesis. RNAseq and metabolite profiling indicate that liver phenotypes of Maf1-/- mice are strongly influenced by systemic inter-organ communication. Notable changes observed in the three phenotypically distinct cohorts include downregulation of Mouse Urinary Proteins, upregulation of Cyp2a4 expression, suggestive of an alteration of Growth Hormone levels or secretion pattern, and downregulation of Angiogenin, a phenomenon that might be directly linked to increased Pol III occupancy of tRNA genes in the main Angiogenin promoter region.
2023-11-28 | PXD040086 | Pride
Project description:MAF1 is a nutrient-sensitive, TORC1-regulated repressor of RNA polymerase III (Pol III). MAF1 downregulation leads to increased lipogenesis in Drosophila melanogaster, Caenorhabditis elegans, and mice. However, Maf1−/− mice are lean as increased lipogenesis is counterbalanced by futile pre-tRNA synthesis and degradation, resulting in increased energy expenditure. We compared Chow-fed Maf1−/− mice with Chow- or High Fat (HF)-fed Maf1hep−/− mice that lack MAF1 specifically in hepatocytes. Unlike Maf1−/− mice, Maf1hep−/− mice become heavier and fattier than control mice with old age and much earlier under a HF diet. Liver ChIPseq, RNAseq and proteomics analyses indicate increased Pol III occupancy at Pol III genes, very few differences in mRNA accumulation, and protein accumulation changes consistent with increased lipogenesis. Futile pretRNA synthesis and degradation in the liver, as likely occurs in Maf1hep−/− mice, thus seems insufficient to counteract increased lipogenesis. Indeed, RNAseq and metabolite profiling indicate that liver phenotypes of Maf1−/− mice are strongly influenced by systemic inter-organ communication. Among common changes in the three phenotypically distinct cohorts, Angiogenin downregulation is likely linked to increased Pol III occupancy of tRNA genes in the Angiogenin promoter.
2023-11-28 | GSE224743 | GEO
Project description:MAF1 is a nutrient-sensitive, TORC1-regulated repressor of RNA polymerase III (Pol III). MAF1 downregulation leads to increased lipogenesis in Drosophila melanogaster, Caenorhabditis elegans, and mice. However, Maf1−/− mice are lean as increased lipogenesis is counterbalanced by futile pre-tRNA synthesis and degradation, resulting in increased energy expenditure. We compared Chow-fed Maf1−/− mice with Chow- or High Fat (HF)-fed Maf1hep−/− mice that lack MAF1 specifically in hepatocytes. Unlike Maf1−/− mice, Maf1hep−/− mice become heavier and fattier than control mice with old age and much earlier under a HF diet. Liver ChIPseq, RNAseq and proteomics analyses indicate increased Pol III occupancy at Pol III genes, very few differences in mRNA accumulation, and protein accumulation changes consistent with increased lipogenesis. Futile pretRNA synthesis and degradation in the liver, as likely occurs in Maf1hep−/− mice, thus seems insufficient to counteract increased lipogenesis. Indeed, RNAseq and metabolite profiling indicate that liver phenotypes of Maf1−/− mice are strongly influenced by systemic inter-organ communication. Among common changes in the three phenotypically distinct cohorts, Angiogenin downregulation is likely linked to increased Pol III occupancy of tRNA genes in the Angiogenin promoter.
2023-11-28 | GSE224916 | GEO
Project description:Contrasting effects of whole-body and hepatocyte-specific deletion of the RNA polymerase III repressor Maf1 in the mouse
| PRJNA933113 | ENA
Project description:Contrasting effects of whole-body and hepatocyte-specific deletion of the RNA polymerase III repressor Maf1 in the mouse [ChIP-Seq]
| PRJNA934546 | ENA
Project description:Contrasting effects of whole-body and hepatocyte-specific deletion of the RNA polymerase III repressor Maf1 in the mouse [RNA-Seq]
| PRJNA932334 | ENA
Project description:MAF1 is a global repressor of RNA polymerase III transcription that regulates the expression of highly abundant noncoding RNAs in response to nutrient availability and cellular stress. Thus, MAF1 function is thought to be important for metabolic economy. Here we show that a whole-body knockout of Maf1 in mice confers resistance to diet-induced obesity and nonalcoholic fatty liver disease by reducing food intake and increasing metabolic inefficiency. Energy expenditure in Maf1(-/-) mice is increased by several mechanisms. Precursor tRNA synthesis was increased in multiple tissues without significant effects on mature tRNA levels, implying increased turnover in a futile tRNA cycle. Elevated futile cycling of hepatic lipids was also observed. Metabolite profiling of the liver and skeletal muscle revealed elevated levels of many amino acids and spermidine, which links the induction of autophagy in Maf1(-/-) mice with their extended life span. The increase in spermidine was accompanied by reduced levels of nicotinamide N-methyltransferase, which promotes polyamine synthesis, enables nicotinamide salvage to regenerate NAD(+), and is associated with obesity resistance. Consistent with this, NAD(+) levels were increased in muscle. The importance of MAF1 for metabolic economy reveals the potential for MAF1 modulators to protect against obesity and its harmful consequences.
| S-EPMC4421982 | biostudies-literature
Project description:Maf1 is negative regulator of RNA polymerase III in yeast. We observed high levels of both primary transcript and end-matured, intron-containing pre-tRNAs in the maf1? strain. This pre-tRNA accumulation could be overcome by transcription inhibition, arguing against a direct role of Maf1 in tRNA maturation and suggesting saturation of processing machinery by the increased amounts of primary transcripts. Saturation of the tRNA exportin, Los1, is one reason why end-matured intron-containing pre-tRNAs accumulate in maf1? cells. However, it is likely possible that other components of the processing pathway are also limiting when tRNA transcription is increased. According to our model, Maf1-mediated transcription control and nuclear export by Los1 are two major stages of tRNA biosynthesis that are regulated by environmental conditions in a coordinated manner.
| S-EPMC3234771 | biostudies-literature
Project description:MAF1, a key repressor of RNA polymerase (pol) III-mediated transcription, has been shown to promote mesoderm formation in vitro. Here, we show that MAF1 plays a critical role in regulating osteoblast differentiation and bone mass. Global deletion of MAF1 (Maf1-/- mice) produced a high bone mass phenotype. However, osteoblasts isolated from Maf1-/- mice showed reduced osteoblastogenesis ex vivo. Therefore, we determined the phenotype of mice overexpressing MAF1 in cells from the mesenchymal lineage (Prx1-Cre;LSL-MAF1 mice). These mice showed increased bone mass. Ex vivo, cells from these mice showed enhanced osteoblastogenesis concordant with their high bone mass phenotype. Thus, the high bone mass phenotype in Maf1-/- mice is likely due to confounding effects from the global absence of MAF1. MAF1 overexpression promoted osteoblast differentiation of ST2 cells while MAF1 downregulation inhibited differentiation, indicating MAF1 enhances osteoblast formation. However, other perturbations used to repress RNA pol III transcription, inhibited osteoblast differentiation. However, decreasing RNA pol III transcription through these perturbations enhanced adipogenesis in ST2 cells. RNA-seq analyzed the basis for these opposing actions on osteoblast differentiation. The different modalities used to perturb RNA pol III transcription resulted in distinct gene expression changes, indicating that this transcription process is highly sensitive and triggers diverse gene expression programs and phenotypic outcomes. Specifically, MAF1 induced genes known to promote osteoblast differentiation. Furthermore, genes that are induced during osteoblast differentiation displayed codon bias. Together, these results reveal a novel role for MAF1 and RNA pol III-mediated transcription in osteoblast fate determination, differentiation, and bone mass regulation.
| S-EPMC9212997 | biostudies-literature