Induction of c-fos and c-myc proto-oncogene expression by epidermal growth factor and transforming growth factor alpha is calcium-independent.
Intracellular calcium has been proposed to be an important mediator of signal transduction by various growth factors. We have studied the role of intracellular calcium in the mitogenic stimulation of C3H 10T1/2 mouse fibroblasts by epidermal growth factor and transforming growth factor alpha. We have found that both these peptides can cause a marked, transient increase in intracellular calcium levels. This rise occurs only in the presence of extracellular calcium. However, this calcium transient is not involved in the accumulation of c-fos and c-myc mRNAs which are elicited by these growth factors, since mRNA induction is observed to an equivalent degree in the absence or presence of extracellular calcium. These results demonstrate that although these growth factors cause an increase in intracellular calcium, the calcium second messenger system is not responsible for the induction of c-fos and c-myc mRNAs in C3H 10T1/2 fibroblasts.
Cutry
A F
AF
Department of Biochemistry, Roswell Park Memorial Institute, Buffalo, New York 14263.
Kinniburgh
A J
AJ
Krabak
M J
MJ
Hui
S W
SW
Wenner
C E
CE
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002478:Cells, Cultured; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects*; D007700:Kinetics; D051379:Mice; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D016760:Proto-Oncogene Proteins c-fos; D016271:Proto-Oncogene Proteins c-myc; D011519:Proto-Oncogenes / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects*; D015291:Transforming Growth Factors / Q000494:pharmacology*
D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D016271:Proto-Oncogene Proteins c-myc; D004815:Epidermal Growth Factor; D015291:Transforming Growth Factors; D011505:Protein-Tyrosine Kinases; D002118:Calcium