UV-induced activation of AP-1 involves obligatory extranuclear steps including Raf-1 kinase.
Irradiation of cells with ultraviolet light (UV) leads to modifications of c-Jun resembling those elicited by phorbol esters or oncogenes, and to enhanced transcription of AP-1-dependent genes. The UV-induced signal also triggers activation of Raf-1 and MAP-2 kinases. A dominant-negative Raf-1 kinase mutant strongly interferes with both phorbol ester and UV-induced AP-1 activation, indicating obligatory involvement of identical components in cytoplasmic signal transduction. Thus, from a presumably nuclear site of energy absorption, a signal needs to be transmitted to the cytoplasm in order to achieve activation of a nuclear transcription factor. Further, signals elicited from different primary sites merge prior to or at the level of activation of Raf-1 kinase.
Radler-Pohl
A
A
Kernforschungszentrum Karlsruhe, Institut für Genetik, Germany.
Sachsenmaier
C
C
Gebel
S
S
Auer
H P
HP
Bruder
J T
JT
Rapp
U
U
Angel
P
P
Rahmsdorf
H J
HJ
Herrlich
P
P
D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D004247:DNA; D004789:Enzyme Activation; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D010703:Phorbol Esters / Q000494:pharmacology; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D019908:Proto-Oncogene Proteins c-raf; D015398:Signal Transduction; D014466:Ultraviolet Rays
D010703:Phorbol Esters; D011518:Proto-Oncogene Proteins; D016755:Proto-Oncogene Proteins c-jun; D004247:DNA; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D017871:Calcium-Calmodulin-Dependent Protein Kinases