Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.1.49 (phosphoenolpyruvate carboxykinase)
 4,654 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Periportal and perivenous hepatocytes were isolated by microdissection from lyophilized liver slices (16 micrometer) from fed and fasted rats and from a human patient. NADP/NADPH cycling was used to determine fructose-1,6-bisphosphatase activity in the isolated hepatocytes (10 ng dry weight). The periportal hepatocytes contain 3 times as much fructose-1,6-bisphosphatase activity as the perivenous hepatocytes. A 24 h fast led to two-fold increase in the activity in the periportal hepatocytes and a four-fold increase in the perivenous hepatocytes. Fructose-1,6-bisphosphatase parallels closely with the key enzyme phosphoenolpyruvate carboxykinase, and therefore can be considered a suitable marker for gluconeogenic capacity.
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PMID:Liver cell heterogeneity. The distribution of fructose-bisphosphatase in fed and fasted rats and in man. 2 36

Fructose-1,6-bisphosphatase (FBPase) is a key regulatory enzyme of gluconeogenesis. In the yeast Saccharomyces cerevisiae, it is only expressed when cells are grown in medium with nonfermentable carbon sources. Addition of glucose to cells leads to inactivation of FBPase and degradation via the ubiquitin-proteasome system. Polyubiquitination of FBPase is carried out by the Gid complex, a multi-subunit ubiquitin ligase. Using tandem affinity purification and subsequent mass spectrometry we identified the Hsp70 chaperone Ssa1 as a novel interaction partner of FBPase. Studies with the temperature-sensitive mutant ssa1-45(ts) showed that Ssa1 is essential for polyubiquitination of FBPase by the Gid complex. Moreover, we show that degradation of an additional gluconeogenic enzyme, phosphoenolpyruvate carboxykinase, is also affected in ssa1-45(ts) cells demonstrating that Ssa1 plays a general role in elimination of gluconeogenic enzymes.
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PMID:The Hsp70 chaperone Ssa1 is essential for catabolite induced degradation of the gluconeogenic enzyme fructose-1,6-bisphosphatase. 2051 52