Two modes of recruitment of E(spl) repressors onto target genes

摘要: The decision of ectodermal cells to adopt the sensory organ precursor fate in Drosophila is controlled by two classes basic-helix-loop-helix transcription factors: proneural Ac and Sc activators promote neural fate, whereas E(spl) repressors suppress it. We show here that proteins m7 mγ are potent inhibitors fate, even in presence of excess activity when their DNA-binding basic domain has been inactivated. Furthermore, these proteins can efficiently repress target genes lack cognate DNA binding sites, as long genes bound by Ac/Sc activators. This E(spl)m7 correlates with their ability interact activators, through which they probably tethered on target enhancers. Analysis reporter organ (bristle) patterns reveals that, addition this indirect recruitment of E(spl) onto enhancers via protein-protein interaction Ac/Sc factors, direct also takes place. Irrespective whether recruited or interaction proteins, co-repressor Groucho always needed for gene repression.