Elizabeth E. Dudenhausen

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Expression of human asparagine synthetase (ASNS), which catalyzes asparagine and glutamate biosynthesis, is transcriptionally induced following amino acid deprivation. Previous overexpression and electrophoresis mobility shift analysis showed the involvement of the transcription factors ATF4, C/EBPbeta, and ATF3-FL through the nutrient-sensing response(More)
Plasma membrane vesicles isolated from intact rat liver (normal hepatocyte) or cultured rat H4 hepatoma cells retain Na+-dependent uptake of 2-aminoisobutyric acid mediated by System A. The carrier was inactivated in normal liver membrane vesicles by either N-ethylmaleimide (NEM) or p-chloromercuribenzene sulfonate (PCMBS). The concentrations required to(More)
CCAAT/enhancer-binding protein beta (C/EBPbeta) is a member of the bZIP family of transcription factors that contribute to the regulation of a wide range of important cellular processes. The data in the present study document that transcription from the human C/EBPbeta gene is induced in response to endoplasmic reticulum stress, such as glucose deprivation,(More)
A nutrient stress signalling pathway is triggered in response to protein or amino acid deprivation, namely the AAR (amino acid response), and previous studies have shown that C/EBPbeta (CCAAT/enhancer-binding protein beta) expression is up-regulated following activation of the AAR. DNA-binding studies, both in vitro and in vivo, have revealed increased(More)
Mammalian cells respond to protein or amino acid (AA) limitation by activating a number of signaling pathways, collectively referred to as the AA response (AAR), that modulate a range of cellular functions, including transcriptional induction of target genes. This study demonstrates that in hepatocellular carcinoma cells, expression of c-JUN, JUN-B, c-FOS,(More)
For animals, dietary protein is critical for the nutrition of the organism and, at the cellular level, protein nutrition translates into amino acid availability. Amino acid deprivation triggers the AAR (amino acid response) pathway, which causes enhanced transcription from specific target genes. The present results show that C/EBPbeta(More)
System A activity is a highly regulated mechanism for the active transport of zwitterionic amino acids into mammalian cells. Monoclonal antibodies generated against a previously unidentified rat liver plasma membrane-associated protein were shown to immunoprecipitate solubilized System A transport activity. The immunoreactive protein was later determined by(More)
It is unclear whether Mediator complex in yeast is necessary for all RNA polymerase II (Pol II) transcription or if it is limited to genes activated by environmental stress. In mammals, amino acid limitation induces SNAT2 transcription through ATF4 binding at an amino acid response element. ATF4 is the functional counterpart to the yeast amino(More)
In the liver, System A-mediated uptake of neutral amino acids may play a key role in metabolic control. Knowing the properties of the solubilized and reconstituted System A activity is important for future studies on the purification of the carrier protein. Solubilization of System A activity by the combination of 2.5% cholate and 4 M urea resulted in(More)