Activation of S6 kinase in astroglial cells by FGFa and FGFb.
Basic (b) and acidic (a) forms of the fibroblast growth factor (FGF) promoted a rapid increase of the cytosolic S6 kinase activity in astroglial cells. S6 kinase activity was maximal 10 min after addition of the factors to cell cultures and remained at this level for at least 30 min. Half-activation of the enzyme was obtained with 3 ng/ml FGFa. Heparin (100 micrograms/ml) potentiated the response to suboptimal concentrations of FGFa. This growth factor appeared to stimulate an astroglial S6 kinase resembling that stimulated by insulin, IGF1, TPA and cAMP. Although FGFb is more potent than FGFa in stimulating proliferation of Chinese hamster lung fibroblasts (CCL39), it was not more efficient than FGFa in stimulating the S6 kinase activity of astroglial cells.
Gavaret
J M
JM
I.N.S.E.R.M. U96, Unité de Recherche sur la Glande Thyroide et la Régulation Hormonale, Le Kremlin-Bicêtre, France.
Matricon
C
C
Pomerance
M
M
Jacquemin
C
C
Toru-Delbauffe
D
D
Pierre
M
M
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000201:enzymology*; D002273:Carcinogens / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000494:pharmacology; D005346:Fibroblast Growth Factors / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D019893:Ribosomal Protein S6 Kinases
D002273:Carcinogens; D007328:Insulin; D005346:Fibroblast Growth Factors; D000242:Cyclic AMP; D011494:Protein Kinases; D019893:Ribosomal Protein S6 Kinases