Project description:Autophagy is a highly conserved self-digestion process, essential to maintain homeostasis and viability in response to nutrient starvation. Although the components of autophagy in the cytoplasm have been well-studied, molecular basis for the epigenetic regulation of autophagy is poorly understood. Here, we identify histone arginine methyltransferase CARM1 as a critical component of autophagy. We found that nutrient starvation increased CARM1 protein level and subsequently histone H3R17 dimethylation. Genome-wide analyses reveal that CARM1 exerts transcriptional coactivator function on autophagy-related genes and lysosomal genes through TFEB. Our findings demonstrate a previously unrecognized role of CARM1-dependent histone arginine methylation as a critical nuclear event of autophagy.
Project description:Coactivator associated arginine methyltransferase I (CARM1, also known as Protein aRginine MethylTransferase 4, or PRMT4) regulates gene expression by multiple mechanisms including methylation of histones and coactivation of steroid receptor transcription. Mice lacking CARM1 are smaller than their littermates, fail to breath, and die shortly after birth, demonstrating the critical role of CARM1 in development.We performed gene expression analysis to identify genes that are responsible for hyperproliferaion in CARM1 knockout lung. RNA extracted from murine lung at E18.5 with carm1 knockouts and wild type controls was hybridised to Affymetrix mouse430.2 GeneChips to identify differentially expressed genes in the disease state.
Project description:Autophagy phenomenon is an essential mechanism to regulate cell homeostasis and is activated by various stresses such as nutrient starvation. It is well known that when autophagy is activated and how important components in the cytoplasm cause a series of reactions, but the regulatory mechanism of transcription in the nucleus is poorly known. Here, we identify that histone demethylase KDM3A plays a crucial role in the transcription of autophagy and lysosomal genes. Notably, KDM3A is increased in transcriptional levels in both glucose and amino acid starvation. Especially, transcriptional increase of histone demethylase in response to glucose starvation is dependent on AMP-activated protein kinase (AMPK). Furthermore, genome-wide analysis reveals that KDM3A acts as a co-activator in the expression of autophagy and lysosomal genes. Our finding of histone demethylase signaling cascade in nucleus, modulating histone demethylation signature is one of the predominant epigenetic event in autophagy activation, thereby providing the functional and mechanistic link between epigenetic control and transcriptional regulation of autophagy upon nutrient starvation.
Project description:The goal of this study is to identify ERalpha-target genes affected by overexpression of the histone arginine methyltransferase CARM1 in breast cancer cells. The roles of CARM1 in ERalpha+ breast cancer was not well characterized. Therefore, we created a Dox inducible CARM1 overexpressing MCF7 cell line where CARM1 is overexpressed by 2 fold to determine the created a Dox-inducible CARM1 overexpressing MCF7 cells for evaluation of the global effects of CARM1 on Eralpha-target gene expression. MCF7-tet-on-CARM1 clone 13 were treated under 4 conditions: DMSO; Dox; E2 (10nM); Dox+E2. In Dox+E2 condition, cells were pre-treated with Dox for 5 days before treating with E2 for 4 hours. 3 biological replicates were included and total of 12 samples were analyzed.
Project description:Multiple signaling pathways ultimately modulate the epigenetic information embedded in the chromatin of gene promoters by recruiting epigenetic enzymes. We found that, in estrogen-regulated gene programming, the acetyltransferase CREB-binding protein (CBP) is specifically and exclusively methylated by the coactivator-associated arginine methyltransferase (CARM1) in vivo. CARM1-dependent CBP methylation and p160 coactivators were required for estrogen-induced recruitment to chromatin targets. Notably, methylation increased the histone acetyltransferase (HAT) activity of CBP and stimulated its autoacetylation. Comparative genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) studies revealed a variety of patterns by which p160, CBP, and methyl-CBP (meCBP) are recruited (or not) by estrogen to chromatin targets. Moreover, significant target gene-specific variation in the recruitment of (1) the p160 RAC3 protein, (2) the fraction of a given meCBP species within the total CBP, and (3) the relative recruitment of different meCBP species suggests the existence of a target gene-specific “fingerprint” for coregulator recruitment. Crossing ChIP-seq and transcriptomics profiles revealed the existence of meCBP “hubs” within the network of estrogen-regulated genes. Together, our data provide evidence for an unprecedented mechanism by which CARM1-dependent CBP methylation results in gene-selective association of estrogen-recruited meCBP species with different HAT activities and specifies distinct target gene hubs, thus diversifying estrogen receptor programming. Examination of estrogen-induced transcription in H3396 cells
Project description:The goal of this study is to identify ERalpha-target genes affected by overexpression of the histone arginine methyltransferase CARM1 in breast cancer cells. The roles of CARM1 in ERalpha+ breast cancer was not well characterized. Therefore, we created a Dox inducible CARM1 overexpressing MCF7 cell line where CARM1 is overexpressed by 2 fold to determine the created a Dox-inducible CARM1 overexpressing MCF7 cells for evaluation of the global effects of CARM1 on Eralpha-target gene expression.
Project description:Coactivator associated arginine methyltransferase I (CARM1, also known as Protein aRginine MethylTransferase 4, or PRMT4) regulates gene expression by multiple mechanisms including methylation of histones and coactivation of steroid receptor transcription. Mice lacking CARM1 are smaller than their littermates, fail to breath, and die shortly after birth, demonstrating the critical role of CARM1 in development.We performed gene expression analysis to identify genes that are responsible for hyperproliferaion in CARM1 knockout lung.
Project description:The goal of this study is to identify ERalpha-target genes affected by knocking down of the histone arginine methyltransferase CARM1 in MCF7 breast cancer cells. The roles of CARM1 in ERalpha+ breast cancer was not well characterized. Therefore, we created a Dox inducible CARM1 knockingdown MCF7 cell line where CARM1 is decreased to 20% of endogeneous level to determine the created a Dox-inducible CARM1shRNA overexpressing MCF7 cells for evaluation of the global effects of CARM1 on ERalpha-target gene expression. MCF7-tet-on-CARM1shRNA clone 1 were treated under 4 conditions: DMSO; Dox; E2 (10nM); Dox+E2. In Dox+E2 condition, cells were pre-treated with Dox for 5 days before treating with E2 for 4 hours. 3 biological replicates were included and total of 12 samples were analyzed.
Project description:The goal of this study is to identify ERalpha-target genes affected by knocking down of the histone arginine methyltransferase CARM1 in MCF7 breast cancer cells. The roles of CARM1 in ERalpha+ breast cancer was not well characterized. Therefore, we created a Dox inducible CARM1 knockingdown MCF7 cell line where CARM1 is decreased to 20% of endogeneous level to determine the created a Dox-inducible CARM1shRNA overexpressing MCF7 cells for evaluation of the global effects of CARM1 on ERalpha-target gene expression.
Project description:One of the most common metabolic defects of cancer cells is the deficiency in arginine synthesis due to suppressed expression of argininosuccinate synthetase 1 (ASS1) which renders cancer cells auxotrophic to external arginine supply. Arginine deprivation has been effectively used as a treatment for leukemias, with several clinical trials on solid tumors underway. We previously showed that in prostate cancer arginine depletion induced mitochondrial dysfunction and excessive ROS production resulting in chromatin autophagy, nuclear DNA leakage, and cellular death, but the detailed mechanism of arginine starvation-induced cell death remains unclear. In this study, we demonstrated that arginine deprivation coordinately suppressed metabolic genes, including those responsible for mitochondrial oxidative phosphorylation (OXPHOS), nucleotide metabolism, and DNA repair. The consequent ROS production and impaired DNA damage response resulted in nuclear DNA leakage and cGAS-STING activation which is accompanied by upregulation of type I interferon response. We also showed that coordinated silencing of OXPHOS and DNA repair genes is caused in part by the depletion of α-ketoglutarate (αKG) and inactivation of histone demethylases. Supplementing cell-permeable dimethyl α-ketoglutarate (DMKG) both reduced repressive histone methylations and partially restored OXPHOS gene expressions, mitochondrial functions, and mitigated nuclear DNA leakage. Using our dietary arginine-restriction model, we demonstrate that arginine starvation slows prostate cancer growth with evidence of enhanced interferon responses and recruitment of immune cells. Our data suggests arginine starvation induces cell killing of ASS1-low cancer cells by metabolic depletion and epigenetic silencing of metabolic genes, leading to DNA damage and leakage. Resulting cGAS-STING activation may further enhance these killing effects. We used microarray to analyze the expression difference between control and arginine-depleted cells to find out what genes involved in the regulation of mitochondrial function and arginine deprivation-induced cell death.