To dissect the regulation of terminal myeloid differentiation, primary response (MyD) genes have been isolated and characterized. MyD genes play important roles in terminal differentiation, growth arrest and apoptosis. The molecular mechanisms for induction of MyD genes at the onset of terminal differentiation have not been elucidated. Activation of MyD genes by differentiation inducers has been studied using M1 myeloid leukemia cells and myeloid cells from bone marrow (BM). JunB was chosen as a paradigm to investigate the activation of MyD genes. The -651-52 JunB IL-6RE has been shown to be necessary and sufficient for JunB induction in M1 cells, and the transcription factor NF-Y binds to the CCAAT element within this region. The purpose of Aim I is to ascertain if the NF-Y complex binds to the JunB promoter in vivo prior to as well as following induction of myeloid differentiation, using chromatin immunoprecipitation (ChIP), as previously observed employing EMSA assays for M1 cells. This will be done using M1 cells and BM. Experiments are delineated in Aim II to establish a role for NF-Y in MyD gene induction and myeloid differentiation. This research plan will yield new information on the regulation of terminal myeloid differentiation, and breakdowns in these controls that can lead to leukemias and anemias, thereby generating tools to ultimately aid in the diagnosis, prognosis and rational therapeutic design for these disorders.
