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Glucose catabolism induces the expression of the L-type pyruvate kinase (L-PK) gene through the glucose response element (GIRE). The metabolic pathway used by glucose after its phosphorylation to glucose 6-phosphate by glucokinase to induce L-PK gene expression in hepatocytes remains unknown. The sugar alcohol xylitol is metabolized to xylulose 5-phosphate,(More)
The L-type pyruvate kinase (L-PK) is a key enzyme of the glycolytic pathway mainly expressed in the liver. Rat liver contains a regulatory protein that inhibits glucokinase (GK) activity. The effect of this protein is greatly reinforced by the fructose 6-phosphate and antagonized by the fructose 1-phosphate (Van Schaftingen, E. (1989) Eur. J. Biochem. 179,(More)
OBJECTIVES A physiological adaptation to a sugar-rich meal is achieved by increased sugar uptake to match dietary load, resulting from a rapid transient translocation of the fructose/glucose GLUT2 transporter to the brush border membrane (BBM) of enterocytes. The aim of this study was to define the contributors and physiological mechanisms controlling(More)
We report here elements for functional characterization of two members of the Saccharomyces cerevisiae Ypt/Rab GTPase activating proteins family (GAP): Gyp5p, a potent GAP in vitro for Ypt1p and Sec4p, and the protein Ymr192wp/APP2 that we propose to rename Gyl1p (GYp like protein). Immunofluorescence experiments showed that Gyp5p and Gyl1p partly(More)
L-type pyruvate kinase (L-PK) is a key enzyme of the glycolytic pathway specifically expressed in the liver and, to a lesser degree, in the small intestine and kidney. One important characteristic of L-PK gene expression is its strong activation by glucose and insulin and its complete inhibition by fasting or glucagon treatment. Having previously(More)
Rab11 and Rab6 guanosine triphosphatases are associated with membranes of the recycling endosomes (REs) and Golgi complex, respectively. Evidence indicates that they sequentially regulate a retrograde transport pathway between these two compartments, suggesting the existence of proteins that must co-ordinate their functions. Here, we report the(More)
The functional role of the different sites binding transcriptional factors on the tissue-specific, glucose-responsive promoter of the L type pyruvate kinase gene (L-PK) has been investigated in transgenic mice. These sites are able to bind, from 3' to 5', HNF1, NF1, HNF4, and MLTF/USF, respectively. We have compared the level of chloramphenicol(More)
The amyloid precursor protein (APP) can be cleaved by α-secretases in neural cells to produce the soluble APP ectodomain (sAPPα), which is neuroprotective. We have shown previously that activation of the purinergic P2X7 receptor (P2X7R) triggers sAPPα shedding from neural cells. Here, we demonstrate that the activation of ezrin, radixin, and moesin (ERM)(More)
L-type pyruvate kinase (L-PK) gene expression is modulated by hormonal and nutritional conditions. We have previously shown that the glucose/insulin response element (GlRE) of the L-PK gene is built around two noncanonical E boxes (element L4) that cooperate closely with a contiguous binding site (element L3). We present in this report the identification of(More)
We previously demonstrated that, in hepatocytes in primary culture, the role of insulin on induction of L-type pyruvate kinase (L-PK) gene expression was mainly to induce glucokinase synthesis, needed for glucose phosphorylation to glucose 6-phosphate. However, we show here that when hepatocytes have been isolated from rats starved for 72 h, glucose and(More)