A requirement for extracellular signal-regulated kinase (ERK) function in the activation of AP-1 by Ha-Ras, phorbol 12-myristate 13-acetate, and serum.
The role of ERK-1 and ERK-2 in wild-type (wt) Ha-Ras, phorbol 12-myristate 13-acetate (PMA), and serum-induced AP-1 activity was studied. Microinjection of ERK-specific substrate peptides inhibited the induction of AP-1 activity by all three stimuli, whereas a control peptide had no effect. By using eukaryotic expression constructs encoding wt ERK-1 and kinase-deficient mutants of ERKs 1 and 2, it was found that ERK-1 and ERK-2 activities are required for AP-1 activation stimulated by either wt Ha-Ras, PMA, or serum. Overexpression of ERK-1 augmented wt Ha-Ras stimulation of AP-1, while having no effect upon PMA or serum stimulation. Overexpression of either kinase-deficient ERK-1 or kinase-deficient ERK-2 partially inhibited AP-1 activation by wt Ha-Ras but had no effect on PMA or serum-induced activation. Coexpression of both interfering mutants abolished AP-1 induction by wt Ha-Ras, PMA, or serum. We conclude that ERKs are necessary components in the pathway leading to the activation of AP-1 stimulated by these agents.
Frost
J A
JA
Department of Medicine, University of California at San Diego, La Jolla 92093-0636.
Geppert
T D
TD
Cobb
M H
MH
Feramisco
J R
JR
D000595:Amino Acid Sequence; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002478:Cells, Cultured; D004789:Enzyme Activation; D005786:Gene Expression Regulation / Q000187:drug effects; D066298:In Vitro Techniques; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects
D010455:Peptides; D016755:Proto-Oncogene Proteins c-jun; D011505:Protein-Tyrosine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D016283:Proto-Oncogene Proteins p21(ras); D013755:Tetradecanoylphorbol Acetate