NSF Award
9118977
The long term objective of the research being proposed is to provide a molecular description of primary events leading to the onset of differentiation in mammalian cells. Specifically, this research will focus on providing a detailed description of the mechanism of action of the protein Id, a molecule shown to inhibit the differentiation process in multiple cell lineages. The main model system that will be sued to study Id activity is the muscle differentiation pathway in which Id has been shown to antagonize the action of the muscle determination gene MyoD. 1) The regions of the Id protein molecule required for its activity will be determined by site directed mutagenesis followed by functional analysis in transfection assays. Both the ability of Id to inhibit myogenesis and its ability to overcome the growth suppressive properties of MyoD will be investigated in these studies. 2) The Id gene will be isolated from a mouse genomic library and the enhancer elements responsible for its regulated expression during differentiation will be identified by deletion analysis, transient transfections and the use of transgenic mice. 3) Inducible versions of the Id gene will be constructed to determine the phenotype of timed over expression of Id in cultured cells and transgenic mice.
