Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.1.1.1 (
alcohol dehydrogenase
)
9,284
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The complete nucleotide sequence of the extracellular glucoamylase gene STA1 from the yeast Saccharomyces diastaticus has been determined. A single open reading frame codes for a 778-amino-acid protein which contains 13 potential N-glycosylation sites. In the 5'- and 3'-flanking regions of the gene, there are striking sequence homologies to the corresponding regions of ADH1 for
alcohol dehydrogenase
and MAT alpha 2 for mating type control in the yeast Saccharomyces cerevisiae. The putative precursor begins with a hydrophobic segment that presumably acts as a signal sequence for secretion. The presumptive signal sequence showed a significant homology to that of Bacillus subtilis alpha-amylase precursor. The next segment, of ca. 320 amino acids, contains a threonine-rich tract in which direct repeat sequences of 35 amino acids exist, and is bordered by a pair of basic amino acid residues (Lys-Lys) which may be a proteolytic processing signal. The carboxy-terminal half of the precursor is a presumptive glucoamylase which contains several peptide segments showing a high degree of homology with alpha-amylases from widely diverse organisms including a procaryote (B. subtilis) and eucaryotes (Aspergillus oryzae and mouse). Analysis of both the nucleotide sequence of the STA1 gene and the amino acid composition of the purified glucoamylase suggested that the putative precursor is processed to yield subunits H and Y of mature enzyme by both trypsin-like and
chymotrypsin-like
cleavages.
...
PMID:Nucleotide sequence of the extracellular glucoamylase gene STA1 in the yeast Saccharomyces diastaticus. 391 17
HepG2 cells were transfected with recombinant plasmids, one carrying the murine
alcohol dehydrogenase
(
ADH
) gene and the other containing the gene encoding human cytochrome P450 2E1 (CYP2E1). One of recombinant clones called VL-17A exhibited
ADH
and CYP2E1 specific activities comparable to those in isolated rat hepatocytes. VL-17A cells oxidized ethanol and generated acetaldehyde, the levels of which depended upon the initial ethanol concentration. Compared with unexposed VL-17A cells, ethanol exposure increased the cellular redox (lactate:pyruvate ratio) and caused cell toxicity, indicated by increased leakage of lactate dehydrogenase into the medium,. Exposure of VL-17A cells to 100mM ethanol significantly elevated caspase 3 activity, an indicator of apoptosis, but this ethanol concentration did not affect caspase 3 activity in parental HepG2 cells. Because ethanol consumption causes a decline in hepatic protein catabolism, we examined the influence of ethanol exposure on proteasome activity in HepG2, VL-17A, E-47 (CYP2E1(+)) and VA-13 (
ADH
(+)) cells. Exposure to 100mM ethanol caused a 25% decline in the
chymotrypsin-like
activity of the proteasome in VL-17A cells, but the enzyme was unaffected in the other cell types. This inhibitory effect on the proteasome was blocked when ethanol metabolism was blocked by 4-methyl pyrazole. We conclude that recombinant VL-17A cells, which express both
ADH
and CYP2E1 exhibit hepatocyte-like characteristics in response to ethanol. Furthermore, the metabolism of ethanol by these cells via
ADH
and CYP2E1 is sufficient to bring about an inhibition of proteasome activity that may lead to apoptotic cell death.
...
PMID:Recombinant Hep G2 cells that express alcohol dehydrogenase and cytochrome P450 2E1 as a model of ethanol-elicited cytotoxicity. 1618