PML-nuclear bodies are involved in cellular serum response.
BACKGROUND: Serum stimulation leads to the activation of various signal transduction pathways in cells, and the resultant signals are integrated into the serum response factor (SRF)-dependent transcription of immediate-early genes such as c-fos. RESULTS: To further characterize this response, we investigated the mechanism which controls serum response transcription in cultured human cells. Frequency of PML (promyelocytic leukaemia)-nuclear bodies (NBs) formation increases shortly after serum stimulation, probably facilitating the interaction of SRF and CBP acetyltransferase at the NBs. PML modulates SRF-mediated c-fos promoter activities upon addition of serum to cells or expression of constitutively active Rho family GTPases. We mapped the region in the SRF that interacts with PML to the C-terminal transactivation domain. An SRF mutant deleted of the transactivation domain neither co-localizes with CBP in NBs nor fulfills its transcriptional role. Under conditions of serum stimulation, the formation of NBs coincides with the immediate-early expression of the endogenous c-fos gene in fibroblasts and in all-trans retinoic acid-treated acute promyelocytic leukaemia NB4 cells. CONCLUSION: These data provide an insight into the involvement of NBs in modulating the transcription of serum-induced immediate-early genes.
Pubmed ID: 12622724 RIS Download
Blood | Cell Nucleus | Humans | Neoplasm Proteins | Nuclear Proteins | Promyelocytic Leukemia Protein | Protein Kinases | Proto-Oncogene Proteins c-fos | Signal Transduction | Transcription Factors | Transcription, Genetic | Tumor Suppressor Proteins