Starvation or diabetes decreases the content but not the mRNA of 6-phosphofructo-2-kinase in rat liver.

In rat liver, the activity of 6-phosphofructo-2-kinase (PFK-2) decreases upon starvation and in diabetes. Cyclic AMP-dependent phosphorylation of the enzyme is not sufficient to account for this decrease. PFK-2 content was therefore measured by immunotitration and relative PFK-2 mRNA levels were determined by hybridization with cDNA probes. The data are compatible with a posttranscriptional mechanism of regulation that involves decreased translational efficiency of PFK-2 mRNA and (or) increased turnover of the PFK-2 protein.