Project description:Characterize the transcriptional response to inositol-choline and snf1 We used microarrays to capture the global responses of inositol-choline concentration and snf deletion in Carbon and Nitrogen limited growth
Project description:The yeast Snf1p/AMP-activated kinase (AMPK) maintains energy homeostasis, controlling metabolic processes and glucose derepression in response to nutrient levels and environmental cues. Under conditions of nitrogen or glucose limitation, Snf1p regulates pseudohyphal growth, a morphological transition characterized by the formation of extended multicellular filaments. During pseudohyphal growth, Snf1p is required for wild-type levels of inositol polyphosphate (InsP), soluble phosphorylated species of the six-carbon cyclitol inositol that function as conserved metabolic second messengers. InsP levels are established through the activity of a family of inositol kinases, including the inositol polyphosphate kinase Kcs1p, which principally generates pyrophosphorylated forms of InsP7 and InsP8. Here, we report that Snf1p regulates Kcs1p, affecting Kcs1p phosphorylation and inositol kinase activity. A snf1 kinase-defective mutant exhibits decreased Kcs1p phosphorylation, and Kcs1p is phosphorylated in vivo at Ser residues 537 and 646 during pseudohyphal growth. By in vitro analysis, Snf1p directly phosphorylates Kcs1p, predominantly at amino acids 537 and 646. A yeast strain carrying kcs1 encoding Ser-to-Ala point mutations at these residues (kcs1-S537A,S646A) shows elevated levels of pyrophosphorylated InsP7, comparable to InsP7 levels observed upon deletion of SNF1. The kcs1-S537A,S646A mutant exhibits decreased pseudohyphal growth, invasive growth, and cell elongation. Transcriptional profiling indicates extensive perturbation of metabolic pathways in kcs1-S537A,S646A. Growth of kcs1-S537A,S646A is affected on medium containing glycerol and antimycin A, consistent with decreased Snf1p signaling. This work identifies Snf1p phosphorylation of Kcs1p, collectively highlighting the interconnectedness of AMPK activity and InsP signaling in coordinating nutrient availability, energy homoeostasis, and cell growth.
Project description:The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is associated with abnormalities of liver lipid metabolism, especially with the accumulation of saturated fatty acids (FA). On the contrary, a diet enriched with n-3 polyunsaturated FA (n-3-PUFA) has been reported to ameliorate the progression of NAFLD. The aim of our study was to investigate the impact of dietary n-3-PUFA enrichment on the development of NAFLD and liver lipidome. Mice were fed for 6 weeks either high-fat methionine choline-deficient diet (MCD) or standard chow (two groups fed MCD, two control groups, both with or without n-3-PUFA). Genome-wide transcriptome analysis of liver tissue was performed and revealed differences in liver mRNA transcriptomes after MCD as well as n-3-PUFA administration.
Project description:The regulation of phospholipid biosynthesis in Saccharomyces cerevisiae through cis-acting upstream activating sequence inositol (UASino) and trans-acting elements, such as the INO2-INO4 complex and OPI1 by inositol supplementation in growth is thoroughly studied. In this study, we provide evidence for the regulation of lipid biosynthesis by phosphatidylinositol-specific phospholipase C (PLC) through UASino and two trans-acting elements. Gene expression analysis and radiolabelling experiments demonstrated that the overexpression of rice PLC in yeast cells altered phospholipid biosynthesis at the levels of transcriptional and enzyme activity.
Project description:The regulation of phospholipid biosynthesis in Saccharomyces cerevisiae through cis-acting upstream activating sequence inositol (UASino) and trans-acting elements, such as the INO2-INO4 complex and OPI1 by inositol supplementation in growth is thoroughly studied. In this study, we provide evidence for the regulation of lipid biosynthesis by phosphatidylinositol-specific phospholipase C (PLC) through UASino and two trans-acting elements. Gene expression analysis and radiolabelling experiments demonstrated that the overexpression of rice PLC in yeast cells altered phospholipid biosynthesis at the levels of transcriptional and enzyme activity.
Project description:The regulation of phospholipid biosynthesis in Saccharomyces cerevisiae through cis-acting upstream activating sequence inositol (UASino) and trans-acting elements, such as the INO2-INO4 complex and OPI1 by inositol supplementation in growth is thoroughly studied. In this study, we provide evidence for the regulation of lipid biosynthesis by phosphatidylinositol-specific phospholipase C (PLC) through UASino and two trans-acting elements. Gene expression analysis and radiolabelling experiments demonstrated that the overexpression of rice PLC in yeast cells altered phospholipid biosynthesis at the levels of transcriptional and enzyme activity. There are two biological replicates two hour and five hour induction with galactose. The genome wide expression of Saccharomyces cerevisiae strain BY4741 harbouring rPLC-pYES2 and a vectro control (pYES2) were compare with each other. (Agilent Gene Expression Saccharomyces cerevisiae 8x15k array AMADID: 016333)
Project description:The regulation of phospholipid biosynthesis in Saccharomyces cerevisiae through cis-acting upstream activating sequence inositol (UASino) and trans-acting elements, such as the INO2-INO4 complex and OPI1 by inositol supplementation in growth is thoroughly studied. In this study, we provide evidence for the regulation of lipid biosynthesis by phosphatidylinositol-specific phospholipase C (PLC) through UASino and two trans-acting elements. Gene expression analysis and radiolabelling experiments demonstrated that the overexpression of rice PLC in yeast cells altered phospholipid biosynthesis at the levels of transcriptional and enzyme activity. There are two biological replicates two hour and five hour induction with galactose. The genome wide expression of Saccharomyces cerevisiae strain BY4741 harbouring (rice) rPLC-pYES2 and a vectro control (pYES2) were compare with each other. (Agilent Gene Expression Saccharomyces cerevisiae 8x15k array AMADID: 016333)
Project description:In this study transcriptome and lipidome profiling of triple negative breast cancer cells subjected to pharmacological inhibition of IRE1α revealed changes in lipid metabolism genes associated with an accumulation of triacylglycerols (TAGs). We identified DGAT2 mRNA, encoding the rate-limiting enzyme in TAG biosynthesis, as a RIDD target. Mechanistically, the DGAT2 transcript is cleaved by IRE1 at guanine 260 within a hairpin stem loop structure. Our results highlight the importance of IRE1 RIDD activity in reprograming cellular lipid metabolism