Which statement accurately describes the effect of insulin on the expression of the gene for glucose 6-phosphatase?
A) Insulin triggers the phosphorylation of PKB, which then phosphorylates FOXO-1. Phosphorylation of FOXO-1 causes a decrease in its degradation by the proteasome, which is associated with an increase in the expression of the gene for glucose 6-phosphatase.
B) Insulin activates PKB by phosphorylation, which then phosphorylates FOXO-1. Phosphorylation of FOXO-1 causes an increase in its degradation by the proteasome, which is associated with an increase in the expression of the gene for glucose 6-phosphatase.
C) Insulin leads to the activation of PKA, which then phosphorylates FOXO-1. Phosphorylation of FOXO-1 causing a decrease in its degradation by the proteasome, which is associated with a decrease in the expression of the gene for glucose 6-phosphatase.
D) Insulin leads to the activation of PKB, which then phosphorylates FOXO-1. Phosphorylation of FOXO-1 causing an increase in its degradation by the proteasome, which is associated with a decrease in the expression of the gene for glucose 6-phosphatase.
E) Insulin activates phosphoprotein phosphatase, which then dephosphorylates FOXO-1. Dephosphorylation of FOXO-1 causes a decrease in its degradation by the proteasome and an increase in the expression of the gene for glucose 6-phosphatase.

Question

Quizplus · Accepted Answer

Insulin activates PKB (also known as Akt), which phosphorylates FOXO-1. This phosphorylation targets FOXO-1 for proteasomal degradation. Since FOXO-1 is a transcription factor that activates genes involved in gluconeogenesis, including glucose 6-phosphatase, its degradation leads to a decrease in the expression of these genes, aligning with insulin's role in lowering blood glucose levels.

Which Statement Accurately Describes the Effect of Insulin on the Expression