First Author | Brüsselbach S | Year | 1995 |
Journal | Oncogene | Volume | 10 |
Issue | 1 | Pages | 79-86 |
PubMed ID | 7824281 | Mgi Jnum | J:22409 |
Mgi Id | MGI:70281 | Citation | Brusselbach S, et al. (1995) Cell proliferation and cell cycle progression are not impaired in fibroblasts and ES cells lacking c-Fos. Oncogene 10(1):79-86 |
abstractText | The transcription factor AP-1 is thought to play an important role in the control of cell proliferation, but the function of individual Fos and Jun family members is a largely unresolved issue. To directly analyse the function of c-Fos in the control of cell proliferation we have used embryonic stem (ES) cells and fibroblasts lacking c-Fos due to a disruption of the c-fos gene by homologous recombination. Our results demonstrate that proliferation of normally cycling cells and reentry of quiescent cells into the cell cycle following serum stimulation are not c-Fos-dependent and occur with similar efficiency in c-fos-/- and control cells. We also show that there is no compensatory overexpression or activation of other known Fos or Jun family members. On the contrary, the c-fos-/- cells showed a reduced induction of fra-1 after serum stimulation which is in agreement with the previous identification of fra-1 as a c-Fos target gene. Comparison of the AP-1 binding and transactivation activities in c-fos-/- and +/+ fibroblasts by electrophoretic mobility antibody supershift and CAT assays suggests that c-Fos is not a major component of AP-1 complexes in these cells. It is therefore conceivable that the lack of any detectable effect on cell proliferation in c-fos-/- cells might be due to a functional redundancy among the different AP-1 family members. |