Quantification of MIR172a and MIR168a in the sera of mice fed Arabidopsis diets. qRT-PCR quantifi... more Quantification of MIR172a and MIR168a in the sera of mice fed Arabidopsis diets. qRT-PCR quantification of plant MIR172a and MIR168a in the sera of mice fed either chow diet or Arabidopsis diets (tg-RICE and tg-146 combined data). Ct values normalized to the mouse endogenous Let-7d,g,i. (TIFF 637 kb)
Quantification of mmu-miR146a from transgenic Arabidopsis lines. qRT-PCR quantification of mmu-mi... more Quantification of mmu-miR146a from transgenic Arabidopsis lines. qRT-PCR quantification of mmu-miR146a expression from eight independent transgenic lines. The arrow indicates the line (tg-146) used for diet preparation. (TIFF 525 kb)
Standard curves of synthetic miRNAs. Standard curves for qRT-PCR analysis generated with serial d... more Standard curves of synthetic miRNAs. Standard curves for qRT-PCR analysis generated with serial dilutions of synthetic MIR2911, amiR-RICE, mmu-miR146a, or C7. (TIFF 762 kb)
The Target of Rapamycin Complex 1 (TORC1) involved in coordination of cell growth and metabolism ... more The Target of Rapamycin Complex 1 (TORC1) involved in coordination of cell growth and metabolism is highly conserved among eukaryotes. Yet the signals and mechanisms controlling its activity differ among taxa, according to their biological specificities. A common feature of fungal and plant cells, distinguishing them from animal cells, is that their plasma membrane contains a highly abundant H+-ATPase which establishes an electrochemical H+ gradient driving active nutrient transport. We have previously reported that in yeast, nutrient-uptake-coupled H+ influx elicits transient TORC1 activation and that the plasma-membrane H+-ATPase Pma1 plays an important role in this activation, involving more than just establishment of the H+ gradient. We show here that the PMA2 H+-ATPase from the plant Nicotiana plumbaginifolia can substitute for Pma1 in yeast, to promote H+-elicited TORC1 activation. This H+-ATPase is highly similar to Pma1 but has a longer carboxy-terminal tail binding 14–3–3 p...
Selective endocytosis followed by degradation is a major mechanism for downregulating plasma memb... more Selective endocytosis followed by degradation is a major mechanism for downregulating plasma membrane transporters in response to specific environmental cues. In Saccharomyces cerevisiae, this endocytosis is promoted by ubiquitylation catalyzed by the Rsp5 ubiquitin-ligase, targeted to transporters via adaptors of the alpha-arrestin family. However, the molecular mechanisms of this targeting and their control according to conditions remain incompletely understood. In this work, we dissect the molecular mechanisms eliciting the endocytosis of Can1, the arginine permease, in response to cycloheximide-induced TORC1 hyperactivation. We show that cycloheximide promotes Rsp5-dependent Can1 ubiquitylation and endocytosis in a manner dependent on the Bul1/2 alpha-arrestins. Also crucial for this downregulation is a short acidic patch sequence in the N-terminus of Can1 likely acting as a binding site for Bul1/2. The previously reported inhibition by cycloheximide of transporter recycling, fr...
Impactful dietary RNA delivery requires improving uptake and enhancing digestive stability. In mo... more Impactful dietary RNA delivery requires improving uptake and enhancing digestive stability. In mouse feeding regimes, we have demonstrated that a plant-based ribosomal RNA (rRNA), MIR2911, is more bioavailable than synthetic MIR2911 or canonical microRNAs (miRNAs). Here mutagenesis was used to discern if MIR2911 has a distinctive sequence that aids stability and uptake. Various mutations had modest impacts while one scrambled sequence displayed significantly enhanced digestive stability, serum stability, and bioavailability. To assess if small RNA (sRNA) bioavailability in mice could be improved by increasing gut permeability, various diets, genetic backgrounds and pharmacological methods were surveyed. An intraperitoneal injection of anti-CD3 antibody enhanced gut permeability which correlated with improved uptake of the digestively stable scrambled MIR2911 variant. However, the bioavailability of canonical miRNAs was not enhanced. Similarly, interleukin-10 (IL-10)-deficient mice a...
Izh2 acts as an integrator of intra- and extracellular signals. It dispatches a single input sign... more Izh2 acts as an integrator of intra- and extracellular signals. It dispatches a single input signal – a change in extracellular Zn concentration – into regulatory networks of several cellular processes, whereby it acts as the second line of cellular adaptation to perturbations to zinc homeostasis.
The yeast protein kinases Sat4/Hal4 and Hal5 are required for the plasma membrane stability of th... more The yeast protein kinases Sat4/Hal4 and Hal5 are required for the plasma membrane stability of the K + transporter Trk1 and some amino acid and glucose permeases. The transcriptomic analysis presented here indicates alterations in the general control of the metabolism of both nitrogen and carbon. Accordingly, we observed reduced uptake of methionine and leucine in the hal4 hal5 mutant. This decrease correlates with activation of the Gcn2-Gcn4 pathway, as measured by expression of the lacZ gene under the control of the GCN4 promoter. However, with the exception of methionine biosynthetic genes, few amino acid biosynthetic genes are induced in the hal4 hal5 mutant, whereas several genes involved in amino acid catabolism are repressed. Concerning glucose metabolism, we found that this mutant exhibits derepression of respiratory genes in the presence of glucose, leading to an increased activity of mitochondrial enzymes, as measured by succinate dehydrogenase (SDH) activity. In addition,...
Quantification of MIR172a and MIR168a in the sera of mice fed Arabidopsis diets. qRT-PCR quantifi... more Quantification of MIR172a and MIR168a in the sera of mice fed Arabidopsis diets. qRT-PCR quantification of plant MIR172a and MIR168a in the sera of mice fed either chow diet or Arabidopsis diets (tg-RICE and tg-146 combined data). Ct values normalized to the mouse endogenous Let-7d,g,i. (TIFF 637 kb)
Quantification of mmu-miR146a from transgenic Arabidopsis lines. qRT-PCR quantification of mmu-mi... more Quantification of mmu-miR146a from transgenic Arabidopsis lines. qRT-PCR quantification of mmu-miR146a expression from eight independent transgenic lines. The arrow indicates the line (tg-146) used for diet preparation. (TIFF 525 kb)
Standard curves of synthetic miRNAs. Standard curves for qRT-PCR analysis generated with serial d... more Standard curves of synthetic miRNAs. Standard curves for qRT-PCR analysis generated with serial dilutions of synthetic MIR2911, amiR-RICE, mmu-miR146a, or C7. (TIFF 762 kb)
The Target of Rapamycin Complex 1 (TORC1) involved in coordination of cell growth and metabolism ... more The Target of Rapamycin Complex 1 (TORC1) involved in coordination of cell growth and metabolism is highly conserved among eukaryotes. Yet the signals and mechanisms controlling its activity differ among taxa, according to their biological specificities. A common feature of fungal and plant cells, distinguishing them from animal cells, is that their plasma membrane contains a highly abundant H+-ATPase which establishes an electrochemical H+ gradient driving active nutrient transport. We have previously reported that in yeast, nutrient-uptake-coupled H+ influx elicits transient TORC1 activation and that the plasma-membrane H+-ATPase Pma1 plays an important role in this activation, involving more than just establishment of the H+ gradient. We show here that the PMA2 H+-ATPase from the plant Nicotiana plumbaginifolia can substitute for Pma1 in yeast, to promote H+-elicited TORC1 activation. This H+-ATPase is highly similar to Pma1 but has a longer carboxy-terminal tail binding 14–3–3 p...
Selective endocytosis followed by degradation is a major mechanism for downregulating plasma memb... more Selective endocytosis followed by degradation is a major mechanism for downregulating plasma membrane transporters in response to specific environmental cues. In Saccharomyces cerevisiae, this endocytosis is promoted by ubiquitylation catalyzed by the Rsp5 ubiquitin-ligase, targeted to transporters via adaptors of the alpha-arrestin family. However, the molecular mechanisms of this targeting and their control according to conditions remain incompletely understood. In this work, we dissect the molecular mechanisms eliciting the endocytosis of Can1, the arginine permease, in response to cycloheximide-induced TORC1 hyperactivation. We show that cycloheximide promotes Rsp5-dependent Can1 ubiquitylation and endocytosis in a manner dependent on the Bul1/2 alpha-arrestins. Also crucial for this downregulation is a short acidic patch sequence in the N-terminus of Can1 likely acting as a binding site for Bul1/2. The previously reported inhibition by cycloheximide of transporter recycling, fr...
Impactful dietary RNA delivery requires improving uptake and enhancing digestive stability. In mo... more Impactful dietary RNA delivery requires improving uptake and enhancing digestive stability. In mouse feeding regimes, we have demonstrated that a plant-based ribosomal RNA (rRNA), MIR2911, is more bioavailable than synthetic MIR2911 or canonical microRNAs (miRNAs). Here mutagenesis was used to discern if MIR2911 has a distinctive sequence that aids stability and uptake. Various mutations had modest impacts while one scrambled sequence displayed significantly enhanced digestive stability, serum stability, and bioavailability. To assess if small RNA (sRNA) bioavailability in mice could be improved by increasing gut permeability, various diets, genetic backgrounds and pharmacological methods were surveyed. An intraperitoneal injection of anti-CD3 antibody enhanced gut permeability which correlated with improved uptake of the digestively stable scrambled MIR2911 variant. However, the bioavailability of canonical miRNAs was not enhanced. Similarly, interleukin-10 (IL-10)-deficient mice a...
Izh2 acts as an integrator of intra- and extracellular signals. It dispatches a single input sign... more Izh2 acts as an integrator of intra- and extracellular signals. It dispatches a single input signal – a change in extracellular Zn concentration – into regulatory networks of several cellular processes, whereby it acts as the second line of cellular adaptation to perturbations to zinc homeostasis.
The yeast protein kinases Sat4/Hal4 and Hal5 are required for the plasma membrane stability of th... more The yeast protein kinases Sat4/Hal4 and Hal5 are required for the plasma membrane stability of the K + transporter Trk1 and some amino acid and glucose permeases. The transcriptomic analysis presented here indicates alterations in the general control of the metabolism of both nitrogen and carbon. Accordingly, we observed reduced uptake of methionine and leucine in the hal4 hal5 mutant. This decrease correlates with activation of the Gcn2-Gcn4 pathway, as measured by expression of the lacZ gene under the control of the GCN4 promoter. However, with the exception of methionine biosynthetic genes, few amino acid biosynthetic genes are induced in the hal4 hal5 mutant, whereas several genes involved in amino acid catabolism are repressed. Concerning glucose metabolism, we found that this mutant exhibits derepression of respiratory genes in the presence of glucose, leading to an increased activity of mitochondrial enzymes, as measured by succinate dehydrogenase (SDH) activity. In addition,...
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Papers by Cecilia Primo