The transcription factors CREB and c-Fos play key roles in NCAM-mediated neuritogenesis in PC12-E2 cells.
The neural cell adhesion molecule (NCAM) stimulates axonal outgrowth by activation of the Ras-mitogen activated protein kinase (MAPK) pathway and by generation of arachidonic acid. We investigated whether the transcription factors, cyclic-AMP response-element binding protein (CREB) and c-Fos play roles in this process by estimating NCAM-dependent neurite outgrowth from PC12-E2 cells grown in co-culture with NCAM-negative or NCAM-positive fibroblasts. PC12-E2 cells were transiently transfected with expression plasmids encoding wild-type or dominant negative forms of CREB and c-Fos or an activated form of the MAPK kinase, MEK2. Alternatively, PC12-E2 cells were treated with arachidonic acid, the cAMP analogue dBcAMP, or protein kinase A (PKA) inhibitors. The negative forms of CREB and c-Fos inhibited neurite outgrowth mediated by NCAM, arachidonic acid, dBcAMP, or MEK2. Neither CREB nor c-Fos could compensate for the inactivation of the other, indicating that both factors are important in NCAM-mediated neuritogenesis. Treatment of primary hippocampal neurons with a synthetic NCAM peptide ligand known to stimulate neurite outgrowth induced phosphorylation of CREB and expression of c-fos. We thus present evidence that NCAM-mediated neurite outgrowth involves a series of signal transduction pathways, including the cAMP/PKA pathway, targeting c-Fos and CREB.
Jessen
U
U
Protein Laboratory, Institute of Molecular Pathology, University of Copenhagen, Copenhagen, Denmark.
Novitskaya
V
V
Pedersen
N
N
Serup
P
P
Berezin
V
V
Bock
E
E
D000818:Animals; D016718:Arachidonic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology; D001369:Axons / Q000378:metabolism; D003994:Bucladesine / Q000494:pharmacology; D002227:Carbazoles; D002478:Cells, Cultured / Q000187:drug effects; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000502:physiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017930:Genes, Reporter; D016762:Genes, fos; D006624:Hippocampus / Q000166:cytology; D007211:Indoles / Q000494:pharmacology; D048370:MAP Kinase Kinase 2; D020935:MAP Kinase Signaling System / Q000187:drug effects; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D009363:Neoplasm Proteins / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000502:physiology*; D019006:Neural Cell Adhesion Molecules / Q000502:physiology*; D016501:Neurites / Q000378:metabolism*; D016716:PC12 Cells / Q000378:metabolism* / Q000648:ultrastructure; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000502:physiology*; D011758:Pyrroles / Q000494:pharmacology; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013873:Thionucleotides / Q000494:pharmacology; D014158:Transcription, Genetic; D014162:Transfection
D002227:Carbazoles; D017362:Cyclic AMP Response Element-Binding Protein; D004791:Enzyme Inhibitors; D007211:Indoles; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D019006:Neural Cell Adhesion Molecules; D016760:Proto-Oncogene Proteins c-fos; D011758:Pyrroles; D011993:Recombinant Fusion Proteins; D013873:Thionucleotides; C016957:adenosine-3',5'-cyclic phosphorothioate; D016718:Arachidonic Acid; C057416:KT 5720; D003994:Bucladesine; D000242:Cyclic AMP; D011505:Protein-Tyrosine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D048370:MAP Kinase Kinase 2; D020929:Mitogen-Activated Protein Kinase Kinases