Early responses of PC-12 cells to NGF and EGF: effect of K252a and 5'-methylthioadenosine on gene expression and membrane protein methylation.
Although epidermal growth factor (EGF) and nerve growth factor (NGF) have markedly different biological effects on PC-12 cells, many of the signaling events following ligand binding are similar. Both EGF and NGF result in the induction of the primary response gene egr-1/TIS8 and increased methylation of a variety of membrane-associated proteins as early as 5 min after EGF or NGF treatment using a methylation assay that detects methyl esters as well as methylated arginine residues. At 20 min after stimulation with these factors, the stimulation of methylation by NGF is greater than that of EGF, especially in the polypeptides of 36-42 and 20-22 kDa. To help dissect the pathways involved in these cellular responses, the protein kinase inhibitor K252a and the methyltransferase inhibitor 5'-methylthioadenosine (MTA) were used. Both K252a and MTA inhibit NGF-, but not EGF-mediated, primary response gene expression. In contrast, MTA, but not K252a, can block NGF-induced membrane associated protein methylation. These data suggest a role for differential protein methylation reactions in EGF and NGF signal transduction.
Kujubu
D A
DA
Department of Medicine, University of California, Los Angeles.
Stimmel
J B
JB
Law
R E
RE
Herschman
H R
HR
Clarke
S
S
D000818:Animals; D002227:Carbazoles / Q000494:pharmacology*; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D003839:Deoxyadenosines / Q000494:pharmacology*; D051766:Early Growth Response Protein 1; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D017874:Immediate-Early Proteins; D026121:Indole Alkaloids; D008565:Membrane Proteins / Q000378:metabolism*; D008745:Methylation / Q000187:drug effects; D009363:Neoplasm Proteins / Q000378:metabolism*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D016716:PC12 Cells / Q000187:drug effects*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D013872:Thionucleosides / Q000494:pharmacology*; D014157:Transcription Factors / Q000096:biosynthesis*
D002227:Carbazoles; D004268:DNA-Binding Proteins; D003839:Deoxyadenosines; D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D017874:Immediate-Early Proteins; D026121:Indole Alkaloids; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D013872:Thionucleosides; D014157:Transcription Factors; D004815:Epidermal Growth Factor; C008500:5'-methylthioadenosine; C049985:staurosporine aglycone; D011493:Protein Kinase C