Differential requirements for p21ras and protein kinase C in the regulation of neuronal gene expression by nerve growth factor and neurokines.
This study used reporter gene constructs containing regulatory regions of the c-fos, vasoactive intestinal peptide, and choline acetyltransferase genes to determine the role of p21ras and protein kinase C in the action of ciliary neurotrophic factor and leukemia inhibitory factor. Down-regulation of protein kinase C with phorbol ester did not affect the induction of either c-fos-beta-galactosidase or vasoactive intestinal peptide-luciferase by ciliary neurotrophic factor or leukemia inhibitory factor. In contrast, while leukemia inhibitory factor induction of choline acetyltransferase-luciferase expression was protein kinase C-independent, there appears to be both protein kinase C-dependent and -independent pathways for induction of choline acetyltransferase-luciferase by ciliary neurotrophic factor. Cotransfection of a dominant-negative mutant p21rasN17 blocked nerve growth factor-mediated induction of c-fos-beta-galactosidase, but did not affect induction of c-fos-beta-galactosidase, vasoactive intestinal peptide-luciferase, or choline acetyltransferase-luciferase by either ciliary neurotrophic factor or leukemia inhibitory factor. Thus, in contrast to the action of nerve growth factor, gene induction by ciliary neurotrophic factor, and leukemia inhibitory factor is ras-independent in IMR-32 neuroblastoma cells.
Department of Pharmacology, School of Medicine, University of Washington, Seattle 98195.
J A
JA
Johnson
N M
NM
Nathanson
D002795:Choline O-Acetyltransferase / Q000235:genetics*; D020934:Ciliary Neurotrophic Factor; D005576:Colforsin / Q000494:pharmacology; D005786:Gene Expression Regulation; D016762:Genes, fos; D006131:Growth Inhibitors / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000494:pharmacology*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D009474:Neurons / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D015533:Transcriptional Activation; D014660:Vasoactive Intestinal Peptide / Q000235:genetics*
D020934:Ciliary Neurotrophic Factor; D006131:Growth Inhibitors; D015850:Interleukin-6; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D005576:Colforsin; D014660:Vasoactive Intestinal Peptide; D002795:Choline O-Acetyltransferase; D011493:Protein Kinase C; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras); D013755:Tetradecanoylphorbol Acetate