Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The regulation of glycolytic genes in response to carbon source in the yeast Saccharomyces cerevisiae has been studied. When the relative levels of each glycolytic mRNA were compared during exponential growth on glucose or lactate, the various glycolytic mRNAs were found to be induced to differing extents by glucose. No significant differences in the stabilities of the PFK2, PGK1, PYK1, or PDC1 mRNAs during growth on glucose or lactate were observed. PYK::lacZ and PGK::lacZ fusions were integrated independently into the yeast genome at the ura3 locus. The manner in which these fusions were differentially regulated in response to carbon source was similar to that of their respective wild-type loci. Therefore, the regulation of glycolytic mRNA levels is mediated at the transcriptional level. When the mRNAs are ordered with respect to the glycolytic pathway, two peaks of maximal induction are observed at phosphofructokinase and pyruvate kinase. These enzymes (i) catalyze the two essentially irreversible steps on the pathway, (ii) are the two glycolytic enzymes that are circumvented during gluconeogenesis and hence are specific to glycolysis, and (iii) are encoded by mRNAs that we have shown previously to be coregulated at the translational level in S. cerevisiae (P. A. Moore, A. J. Bettany, and A. J. P. Brown, NATO ASI Ser. Ser. H Cell Biol. 49:421-432, 1990). This differential regulation of glycolytic mRNA levels might therefore have a significant influence upon glycolytic flux in S. cerevisiae.
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PMID:Yeast glycolytic mRNAs are differentially regulated. 192 48

1. The effects of intragastric glucose feeding and L-tri-iodothyronine (T3) administration on rates of hepatic and brown-fat lipogenesis in vivo were examined in fed and 48 h-starved rats. 2. T3 treatment increased hepatic lipogenesis in the fed but not the starved animals. Brown-fat lipogenesis was unaffected or slightly decreased by T3 treatment of fed or starved rats. 3. Intragastric glucose feeding increased hepatic lipogenesis in control or T3-treated fed rats, but did not increase hepatic lipogenesis in starved control rats. Glucose feeding increased hepatic lipogenesis if the starved rats were treated with T3. Glucose feeding increased rates of brown-fat lipogenesis in all experimental groups. The effects of glucose feeding on liver and brown-fat lipogenesis were mimicked by insulin injection. 4. The increase in hepatic lipogenesis in T3-treated 48 h-starved rats after intragastric glucose feeding was prevented by short-term insulin deficiency, but not by (-)-hydroxycitrate, an inhibitor of ATP citrate lyase. The increase in lipogenesis in brown adipose tissue in response to glucose feeding was inhibited by both short-term insulin deficiency and (-)-hydroxycitrate. 5. The results tend to preclude pyruvate kinase and acetyl-CoA carboxylase as the sites of interaction of insulin and T3 in the regulation of hepatic lipogenesis in 48 h-starved rats. Other potential sites of interaction are discussed.
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PMID:Interactions between insulin and thyroid hormone in the control of lipogenesis. 613 16

Brown-adipose tissue mitochondria of hamster and rat contain phosphoenolpyruvate carboxykinase (EC 4.1.1.32). In the presence of ketoglutarate and malate, phosphoenolpyruvate is formed and exported from mitochondria. Phosphoenolpyruvate formation is inhibited by 1,2,3-benzenetricarboxylate. It is proposed that phosphoenolpyruvate carboxykinase together with pyruvate carboxylase and pyruvate kinase forms a phosphoenolpyruvate shuttle through which energy produced by the Krebs cycle in mitochondria may be exported to cytosol.
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PMID:Phosphoenolpyruvate shuttle--transport of energy from mitochondria to cytosol. 686 29

The nitration of protein tyrosine residues represents an important post-translational modification during development, oxidative stress, and biological aging. To rationalize any physiological changes with such modifications, the actual protein targets of nitration must be identified by proteomic methods. While several studies have used proteomics to screen for 3-nitrotyrosine-containing proteins in vivo, most of these studies have failed to prove nitration unambiguously through the actual localization of 3-nitrotyrosine to specific sequences by mass spectrometry. In this paper we have applied sequential solution isoelectric focusing and SDS-PAGE for the proteomic characterization of specific 3-nitrotyrosine-containing sequences of nitrated target proteins in vivo using nanoelectrospray ionization-tandem mass spectrometry. Specifically, we analyzed proteins from the skeletal muscle of 34-month-old Fisher 344/Brown Norway F1 hybrid rats, a well accepted animal model for biological aging. We identified the 3-nitrotyrosine-containing sequences of 11 proteins, including cytosolic creatine kinase, tropomyosin 1, glyceraldehyde-3-phosphate dehydrogenase, myosin light chain, aldolase A, pyruvate kinase, glycogen phosphorylase, actinin, gamma-actin, ryanodine receptor 3, and neurogenic locus notch homolog. For creatine kinase and neurogenic locus notch homolog, two 3-nitrotyrosine-containing sequences were identified, i.e. at positions 14 and 20 for creatine kinase and at positions 1175 and 1205 for the neurogenic locus notch homolog. The selectivity of the in vivo nitration of creatine kinase at Tyr14 and Tyr20 does not correspond to the product selectivity in vitro, where exclusively Tyr82 was nitrated when creatine kinase was exposed to peroxynitrite. The latter experiments demonstrate that the in vitro exposure of an isolated protein to peroxynitrite may not always be a good model to mimic protein nitration in vivo.
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PMID:Proteomic analysis of protein nitration in aging skeletal muscle and identification of nitrotyrosine-containing sequences in vivo by nanoelectrospray ionization tandem mass spectrometry. 1585 74

Metabolic alterations have been characterized in various heart diseases. However, no data are available concerning metabolic changes during acute rejection episodes. Heterotopic heart transplantations in rats were done using Lewis rats as donors and recipients as a control group. The rejection group included Brown-Norway rat donors to Lewis rat recipients. Nonoperated hearts were also studied. Enzyme activities were determined for phosphofructokinase, pyruvate kinase, and lactate dehydrogenase. There were no alterations in the control group compared to nonoperated hearts. However, the rejection cohort of hearts showed decreased glycolytic enzymes. Although lactate dehydrogenase maintained similar levels compared to the control group, phosphofructokinase showed only 50% activity, and pyruvate kinase showed less than 10% of the activity compared with controls. These results suggested that metabolic alterations in rejected hearts differ from other cardiomyopathies.
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PMID:Glycolytic enzyme activities are decreased during acute rejection in transplanted rat hearts. 1638 41