Nuclear responses to protein kinase C signal transduction are sensitive to gravity changes.
A number of studies have suggested that gravity changes may influence mammalian cell growth and differentiation. To obtain insight in the molecular mechanisms underlying these effects, we have studied immediate early gene expression in response to activation of cytoplasmic signal transduction under microgravity conditions. In this paper we show that epidermal growth factor (EGF)- and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced expression of the c-fos and c-jun protooncogenes is decreased in microgravity, while no effect of gravity changes was observed on A23187- and forskolin-induced expression of these genes. These decrease in c-fos expression was not due to delayed kinetics under microgravity. These results demonstrate that gravity differentially modulates distinctive signal transduction pathways.
Hubrecht Laboratory, Netherlands Institute for Developmental Biology, Utrecht.
R P
RP
de Groot
P J
PJ
Rijken
J
J
den Hertog
J
J
Boonstra
A J
AJ
Verkleij
S W
SW
de Laat
W
W
Kruijer
D002467:Cell Nucleus / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005786:Gene Expression Regulation; D016762:Genes, fos; D016758:Genes, jun; D006112:Gravitation; D006801:Humans; D011493:Protein Kinase C / Q000378:metabolism*; D015398:Signal Transduction; D013026:Space Flight; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D004815:Epidermal Growth Factor; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate