Role of Drosophila IKK gamma in a Toll-independent antibacterial immune response

We have generated, by ethylmethane sulfonate mutagenesis, loss-of-function mutants in the Drosophila homolog of the mammalian I-kappa B kinase (IKK) c omplex component IKK gamma (also called NEMO). Our data show that Drosophil a IKK gamma is required for the Relish-dependent immune induction of the ge nes encoding antibacterial peptides and for resistance to infections by Esc herichia coli. However, it is not required for the Toll-Dip-dependent antif ungal host: defense,The results indicate distinct control mechanisms of the Rel-like transactivators DIF and Relish in the Drosophila innate immune re sponse and show that Drosophila Toll does not signal through a IKK gamma-de pendent signaling complex. Thus, in contrast to the vertebrate inflammatory response, IKK gamma is required for the activation of only one immune sign aling pathway in Drosophila.