Project description:The dystrophin-glycoprotein complex connects the cytoskeleton with base membrane components such as laminin through unique O-glycans displayed on α-dystroglycan (α-DG). Genetic impairment of elongation of these glycans causes congenital muscular dystrophies. We previously identified that glycerol phosphate (GroP) can cap the core part of the α-DG O-glycans and terminate their further elongation. This study examined the possible roles of the GroP modification in cancer malignancy, focusing on colorectal cancer. We found that the GroP modification critically depends on PCYT2, which serves as cytidine 5'-diphosphate-glycerol (CDP-Gro) synthase. Furthermore, we identified a significant positive correlation between cancer progression and GroP modification, which also correlated positively with PCYT2 expression. Moreover, we demonstrate that GroP modification promotes the migration of cancer cells. Based on these findings, we propose that the GroP modification by PCYT2 disrupts the glycan-mediated cell adhesion to the extracellular matrix and thereby enhances cancer metastasis. Thus, the present study suggests the possibility of novel approaches for cancer treatment by targeting the PCYT2-mediated GroP modification.
Project description:Cellular senescence impacts many physiological and pathological processes. A durable cell cycle arrest, inflammatory secretory phenotype, and metabolic reprogramming characterize it. Identifying common and specific metabolic liabilities in senescence provide novel inroads to exploit senescence targeting for health benefits. Here, we use dynamic transcriptome and metabolome profiling in different senescence subtypes to reveal common and specific metabolic signatures. Specifically, we pinpoint the homeostatic switch of glycerol-3-phosphate (G3P) and phosphoethanolamine (PEtn) accumulation, intimately linking lipid metabolism to the senescence gene expression program. Mechanistically, p53-dependent glycerol kinase (GK) activation and post-translational inactivation of Phosphate Cytidylyltransferase 2- Ethanolamine (PCYT2) regulate this metabolic switch, which is senogenic. Conversely, G3P phosphatase (G3PP) and Ethanolamine-Phosphate Phospho-Lyase (ETNPPL)-based scavenging of G3P and PEtn is senomorphic. Collectively, our study ties the G3P-PEtn homeostatic switch to controlling lipid droplet biogenesis and phospholipid flux in senescent cells, providing a potential, novel therapeutic avenue for senescence targeting in pathophysiology.
Project description:Cellular senescence impacts many physiological and pathological processes. A durable cell cycle arrest, inflammatory secretory phenotype, and metabolic reprogramming characterize it. Identifying common and specific metabolic liabilities in senescence provide novel inroads to exploit senescence targeting for health benefits. Here, we use dynamic transcriptome and metabolome profiling in different senescence subtypes to reveal common and specific metabolic signatures. Specifically, we pinpoint the homeostatic switch of glycerol-3-phosphate (G3P) and phosphoethanolamine (PEtn) accumulation, intimately linking lipid metabolism to the senescence gene expression program. Mechanistically, p53-dependent glycerol kinase (GK) activation and post-translational inactivation of Phosphate Cytidylyltransferase 2- Ethanolamine (PCYT2) regulate this metabolic switch, which is senogenic. Conversely, G3P phosphatase (G3PP) and Ethanolamine-Phosphate Phospho-Lyase (ETNPPL)-based scavenging of G3P and PEtn is senomorphic. Collectively, our study ties the G3P-PEtn homeostatic switch to controlling lipid droplet biogenesis and phospholipid flux in senescent cells, providing a potential, novel therapeutic avenue for senescence targeting in pathophysiology.
Project description:The goal of the study is to use Next generation sequencing (RNA-seq) to study the underlying regulation of glycerol metabolism in mixed culture fermentation (glucose and glycerol) of Rhodosporidium toruloides. We sequenced the RNA from 4 different samples in the mixed culture (glucose and glycerol) with 2 replicates each. Transcriptional profiles showed that glycerol might be produced intracellularly and glycerol kinase (GUT1) and glycerol 3–phosphate dehydrogenase (GUT2) enzymes were not down-regulated in the presence of glucose at the transcriptional level. It also showed that this yeast has a different regulation compared to S.cerevisiae. Certain insights into lipid biosynthesis on these mixed cultures are provided at systems level. This analysis provides interesting targets for metabolic engineering in this organism growing on glucose and glycerol.
Project description:The genome of the osmophilic Aspergillus wentii, unlike that of the osmotolerant Aspergillus nidulans, contains only the gfdA but not the gfdB glycerol 3-phosphate dehydrogenase gene. Here, we studied transcriptomic changes of A. nidulans (reference strain and DgfdB gene deletion mutant) and A. wentii (reference strain and An-gfdB expressing mutant) elicited by high osmolarity. A. nidulans showed canonic hyperosmotic stress response characterized by upregulation of trehalose and glycerol metabolism genes (including gfdB) as well as genes of the high-osmolarity glycerol (HOG) map kinase pathway. Deletion of gfdB caused only negligible alterations in the transcriptome suggesting that the glycerol metabolism was flexible enough to compensate for the missing GfdB activity in this species. A. wentii responded differently to increased osmolarity than A. nidulans: E.g.; bulk upregulation of glycerol and trehalose metabolism genes as well as HOG pathway genes were not detected. Expression of An-gfdB in A. wentii did not abolish osmophilia, but it reduced growth and caused much bigger alterations in the transcriptome than the missing gfdB gene did in A. nidulans. Flexible glycerol metabolism and hence two differently regulated gfd genes may be more beneficial for osmotolerant (living under changing osmolarity) than for osmophilic (living under constantly high osmolarity) species.
Project description:Dunaliella salina, a unicellular and eukaryotic alga, has been found as one of the most salt-tolerant eukaryote with a short growth period and wide practical applications. To elucidate the underlying molecular mechanism involved in the response to salinity and its different effects, RNA-seq was used for global transcriptome profiling of D. salina exposed to NaCl, Sorbiol and H2O2 stress. To maintain osmotic pressure homeostasis under suboptimal environment condition, starch breakdown catalyzed by both alpha-amylase (AMY) and glycogen phosphorylase (PYG) with consecutive expression patterns and low activity of PYG at the beginning of salt stress might be caused by a shortage of ATP because of impaired photosynthesis. Moreover, clustering analysis of differentially expressed genes (DEGs) indicated that starch and sucrose metabolism as well as glycerol metabolism reprogrammed under high salt stress only. For redox homeostasis, glycerol-3-phosphate shuttle performed by mitochondrial glycerol-3-phosphate dehydrogenases (GPDHs) participates the redox imbalance under abiotic stresses. c23777_g1 is a gene of D. salina involved in glycerol 3 phosphate (G3P) shuttle under various abiotic stresses while c25199_g1 is a gene of G3P shuttle induced only by osmotic stress.
Project description:WT and rme1 KO K. lactis cells (a, alpha, and a/alpha) were grown in YEPD, phosphate starvation and phosphate starvation with the addition of alpha pheromone. The goal was to identify cell-type regulated genes and to determine the effects of growth media on the regulation of cell-type regulated genes
Project description:WT and rme1 KO K. lactis cells (a, alpha, and a/alpha) were grown in YEPD, phosphate starvation and phosphate starvation with the addition of alpha pheromone. The goal was to identify cell-type regulated genes and to determine the effects of growth media on the regulation of cell-type regulated genes Expression was measured relative to pooled references, note that only the arrays with matched pooled references can be compared to each other
Project description:Cells must appropriately sense and integrate multiple metabolic resources to commit to proliferation. Here, we report that cells regulate nitrogen (amino acid) and carbon metabolic homeostasis through tRNA U34-thiolation. Despite amino acid sufficiency, tRNA-thiolation deficient cells appear amino acid starved. In these cells, carbon flux towards nucleotide synthesis decreases, and trehalose synthesis increases, resulting in metabolic a starvation-signature. Thiolation mutants have only minor translation defects. However, these cells exhibit strongly decreased expression of phosphate homeostasis genes, mimicking a phosphate-limited state. Reduced phosphate enforces a metabolic switch, where glucose-6-phosphate is routed towards storage carbohydrates. Notably, trehalose synthesis, which releases phosphate and thereby restores phosphate availability, is central to this metabolic rewiring. Thus, cells use thiolated tRNAs to perceive amino acid sufficiency, and balance amino acid and carbon metabolic flux to maintain metabolic homeostasis, by controlling phosphate availability. These results further biochemical explain how phosphate availability determines a switch to a ‘starvation-state’.