FGF and stress regulate CREB and ATF-1 via a pathway involving p38 MAP kinase and MAPKAP kinase-2.
Fibroblast growth factor (FGF) activates a protein kinase cascade in SK-N-MC cells that regulates gene expression at a cyclic-AMP response element (CRE) by stimulating the transcriptional activity of CREB. The activation of CREB is prevented by a dominant negative mutant of Ras and triggered via the same site (Ser133) that becomes phosphorylated in response to cyclic AMP and Ca2+. However, the effect of FGF is not mediated by cyclic AMP-dependent protein kinase, TPA-sensitive isoforms of protein kinase-C, p70S6K or p90rsk (all of which phosphorylate CREB at Ser133 in vitro). Instead, we identify the FGF-stimulated CREB kinase as MAP kinase-activated protein (MAPKAP) kinase-2, an enzyme that lies immediately downstream of p38 MAP kinase, in a pathway that is also stimulated by cellular stresses. We show that MAPKAP kinase-2 phosphorylates CREB at Ser133 in vitro, that the FGF- or stress-induced activation of MAPKAP kinase-2 and phosphorylation of CREB and ATF-1 are prevented by similar concentrations of the specific p38 MAP kinase inhibitor SB 203580, and that MAPKAP kinase-2 is the only detectable SB 203580-sensitive CREB kinase in SK-N-MC cell extracts. We also show that transfection of RK/p38 MAP kinase in SK-N-MC cells, but not transfection of p44 MAP kinase, activates Gal4-CREB-dependent transcription via Ser133. These findings identify a new growth factor and stress-activated signaling pathway that regulates gene expression at the CRE.
Tan
Y
Y
Cell Signaling Laboratory, New England Biolabs, Beverly, MA 01915, USA.
Rouse
J
J
Zhang
A
A
Cariati
S
S
Cohen
P
P
Comb
M J
MJ
D051697:Activating Transcription Factor 1; D000595:Amino Acid Sequence; D001253:Astrocytes / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D004268:DNA-Binding Proteins; D004789:Enzyme Activation; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism
D051697:Activating Transcription Factor 1; D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D014157:Transcription Factors; D005346:Fibroblast Growth Factors; D011494:Protein Kinases; D010738:Type C Phospholipases; D018631:ras Proteins; D013755:Tetradecanoylphorbol Acetate