Nuclear localization of c-Fos, but not v-Fos proteins, is controlled by extracellular signals.
We report here that transport of the protein product of the c-fos proto-oncogene from the cytoplasm, where it is synthesized, into the nucleus, where it operates as part of the AP-1 transcription complex, is not spontaneous but depends on the continuous stimulation of cells by serum factors. A labile protein inhibitor of transport, the effect of which is reversed by cAMP, is responsible for retention of c-Fos protein within the cytoplasm of serum-starved fibroblasts. In contrast, v-Fos proteins transduced by the murine retroviruses FBJ and FBR, which remain nuclear in the absence of serum, evade the translocation control, which therefore appears to contribute to their tumorigenic potential.
Roux
P
P
URA CNRS 1191 Génétique Moléculaire, Laboratoire de Biologie Moléculaire Université de Montpellier II, France.
Blanchard
J M
JM
Fernandez
A
A
Lamb
N
N
Jeanteur
P
P
Piechaczyk
M
M
D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D003470:Culture Media; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology; D005455:Fluorescent Antibody Technique; D016761:Oncogene Proteins v-fos; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos; D015398:Signal Transduction; D014162:Transfection
D003470:Culture Media; D016761:Oncogene Proteins v-fos; D009856:Oncogene Proteins, Viral; D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D011505:Protein-Tyrosine Kinases