The dorsal-related immunity factor, Dif, is a sequence-specific trans-activator of Drosophila Cecropin gene expression.

摘要: Abstract A new member of the Rel family transcription factors, dorsal-related immunity factor, Dif, was recently cloned and suggested to be involved in regulating immune response Drosophila. Despite its classification as a member, Dif cDNA-encoded product has not been proven previously factor. We now present evidence that gene trans-activates Drosophila Cecropin A1 co-transfection assays. The transactivation requires 40 bp upstream element including an insect kappa B-like motif. A dimer motif 5'-GGGGATTTTT inserted into minimal promoter conferred high levels reporter expression by while multimer several mutated versions this activated, demonstrating sequence specificity Dif. Full trans-activation C-terminal part protein. morphogen dorsal (dl) can also activate promoter, but lesser extent less sequence-specific manner than Simultaneous overexpression dl assays revealed possesses dominant negative effect on transactivation. This study establishes is factor probably key activator