Expression
Genes coding for the enzyme are primarily expressed in the liver, in the kidney cortex and (to a lesser extent) in the β-cells of the pancreatic islets and intestinal mucosa (especially during times of starvation). According to Surholt and Newsholme, Glc 6-Pase is present in a wide variety of muscles across the animal kingdom, albeit at very low concentrations. . Thus, the glycogen that muscles store is not usually available for the rest of the body's cells because glucose-6-phosphate cannot cross the sarcolemma unless it is dephosphorylated. The enzyme plays an important role during periods of fasting and when glucose levels are low. It has been shown that starvation and diabetes induces a 2-3-fold increase in Glc-6-Pase activity in the liver. Glc 6-Pase activity also increases dramatically at birth when an organism becomes independent of the mothers source of glucose. The human Glc 6-Pase gene contains five exons spanning approximately 125.5 kb DNA located on chromosome 17q21.
Read more about this topic: Glucose 6-phosphatase
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