M. Dalmau et al., CONTROL OF FRUCTOSE 2,6-BISPHOSPHATE METABOLISM BY DIFFERENT MITOGENIC SIGNALS IN SWISS 3T3 FIBROBLASTS, Experimental cell research, 212(1), 1994, pp. 93-96
The mitogenic signals that control fructose 2,6-bisphosphate metabolis
m in murine Swiss 3T3 fibroblasts have been studied. Bombesin, vasopre
ssin, insulin, protein kinase C activation by phorbol esters, or incre
ase in the intracellular cAMP concentration by forskolin induced an in
crease in fructose 2,6-bisphosphate levels. When the cells were incuba
ted in the presence of insulin or phorbol esters, an increase in the V
-max of 6-phosphofructo-2-kinase activity was observed. However, forsk
olin did not produce this effect. The increase in 6-phosphofructo-2-ki
nase activity elicited by phorbol 12,13-dibutyrate was blocked by cycl
oheximide. In contrast, the effect of insulin did not require protein
synthesis. This study demonstrates that different mitogenic signal tra
nsduction pathways control the levels of fructose 2,6-bisphosphate. Th
e high rate of glycolysis in proliferating Swiss 3T3 cells may be expl
ained by an increase in the levels of this regulatory metabolite. (C)
1994 Academic Press, Inc.