RAT-LIVER-TYPE PHOSPHOFRUCTOKINASE MESSENGER-RNA - STRUCTURE, TISSUE DISTRIBUTION AND REGULATION

We have cloned a full-length cDNA for rat-liver-type phosphofructokinase. The similarities of the rat liver-type phosphofructokinase mRNA to the human and mouse counterparts were 94% and 99% in their amino acid sequences and 88% and 94% in the nucleotide sequences of their coding regions, respectively. Rat liver-type phosphofructokinase mRNA was expressed in all tissues examined, but its level was regulated tissue-specifically. The nutritional and hormonal regulations of the mRNA in the liver were examined in comparison with those of two other key glycolytic enzymes, glucokinase and L-type pyruvate kinase. The level of liver-type phosphofructokinase mRNA was essentially unchanged by starvation (72 h) or diabetes. The mRNA level also did not change significantly on refeeding starved rats on a high carbohydrate diet, or treating diabetic ones with insulin. These results suggested that rat liver-type phosphofructokinase mRNA in the liver was not under control of diet or insulin, in contrast to glucokinase and L-type pyruvate kinase.