Mechanism of recognition and binding of Ultrabithorax

Abstract Hox genes are highly conserved throughout metazoan evolution and code for homeodomain containing transcription factors that control specific developmental pathways. Ultrabithorax (Ubx) exerts its function mainly through activation or repression of downstream genes. Only a few direct target genes of Ubx have been identified and studied in detail therefore mechanism of Ubx mediated control of its target gene is far from complete. Understanding the mechanisms by which Ubx regulates its targets requires the knowledge of target genes and of sequence motifs that serve as recognition and binding elements for Ubx. By employing chip-on-chip and bioinformatics approach, our lab identified a large number of downstream targets of Ubx. The sequence analyses of these genes have suggested few potential Ubx-binding and/or recognition motifs. Here we report the results of cell-based luciferase assays to confirm if these motifs are indeed Ubx-response elements and understand the mechanism of activation and repression.