Regulation of 6-phosphofructo-1-kinase activity in ras-transformed rat-1 fibroblasts

Arch Biochem Biophys. 1991 May 1;286(2):586-90. doi: 10.1016/0003-9861(91)90084-v.


Fructose 2,6-bisphosphate (F-2,6-P2) stimulated glycolysis in cell-free extracts of both normal and ras-transfected rat-1 fibroblasts. The extract of the transformed cell glycolyzed more rapidly in both the absence and the presence of F-2,6-P2 than the extract of the parent fibroblast. Addition of mitochondrial ATPase (F1) or inorganic phosphate (Pi) further stimulated lactate production in both cell lines. F-2,6-P2 stimulated the 6-phosphofructo-1-kinase (PFK-1) activity in extracts of normal and transfected cells. The activity in extracts of transformed cells tested with a fructose 6-phosphate regenerating system was considerably higher than in the extract of normal cells. Stimulation of PFK-1 activity by cAMP of both cell lines was not as pronounced as that by F-2,6-P2. In the absence of F-2,6-P2 the PFK-1 activity was strongly inhibited in the transformed cell by ATP concentrations higher than 1 mM, whereas in the normal cell only a marginal inhibition was noted even at 2 or 3 mM ATP. F-2,6-P2 reversed the inhibition of PFK-1 by ATP. Nicotinamide adenine dinucleotide (NAD) at 100 microM (in the presence of 2 mM ATP and 1 microM F-2,6-P2) stimulated PFK-1 activity only in the transformed cell, whereas nicotinamide adenine dinucleotide phosphate (NADP) inhibited PFK-1 activity (in the presence or absence of 1 microM F-2,6-P2) in extracts of both cell lines. No previous observations of stimulation or inhibition by NAD or NADP on PFK-1 activity appear to have been reported. A threefold increase in the intracellular concentration of F-2,6-P2 was observed after transfection of rat-1 fibroblast by the ras oncogene. We conclude from these data that the PFK-1 activity of ras-transfected rat-1 fibroblasts shows a greater response to certain stimulating and inhibitory regulating factors than that of the parent cell.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Line
  • Cell Transformation, Neoplastic*
  • Cell-Free System
  • Fibroblasts / enzymology
  • Fructose / pharmacology
  • Fructosediphosphates / metabolism
  • Fructosediphosphates / pharmacology
  • Genes, ras*
  • Glycolysis / drug effects
  • Kinetics
  • Lactates / metabolism
  • Phosphates / pharmacology
  • Phosphofructokinase-1 / metabolism*
  • Rats


  • Fructosediphosphates
  • Lactates
  • Phosphates
  • Fructose
  • fructose 2,6-diphosphate
  • Phosphofructokinase-1