A Binding Site for Multiple Transcriptional Activators in the fushi tarazu Proximal Enhancer Is Essential for Gene Expression In Vivo

摘要: The Drosophila homeobox gene fushi tarazu (ftz) is expressed in a highly dynamic striped pattern early embryos. A key regulatory element that controls the ftz proximal enhancer, which mediates positive autoregulation via multiple binding sites for Ftz protein. In addition, enhancer necessary stripe establishment prior to onset of autoregulation. We previously identified nine nuclear proteins core 323-bp region enhancer. Three these interact with same cohort vitro. showed receptor Ftz-F1 interacts this repeated module. Here we purified additional interacting module from extracts. Peptide sequences zinc finger protein Ttk and transcription factor Adf-1 were obtained. While thought be repressor stripes, have shown both activate site-dependent fashion. These two are ubiquitously at time suggesting either may expression alone or combination roles tested vivo, by site-directed mutagenesis individual sites. three Ftz-F1‐Adf-1‐Ttk found functionally redundant essential transgenic Thus, biochemical analysis cis-acting modules required vivo. finding underscores high degree redundancy built into embryonic networks.