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Origins of immunity: Relish, a compound Rel-like gene in the antibacterial defense of Drosophila

Dushay, M.S., Asling, B., Hultmark, D.
Proceedings of the National Academy of Sciences of the United States of America 1996 v.93 no.19 pp. 10343-10347
Drosophila melanogaster, transcription factors, DNA-binding proteins, nucleotide sequences, amino acid sequences, gene expression, messenger RNA, immune system, immune response, Enterobacter cloacae, embryogenesis, complementary DNA, chromosome mapping, animal proteins, embryo (animal), promoter regions
NF-kappaB/Rel transcription factors are central regulators of mammalian immunity and are also implicated in the induction of cecropins and other antibacterial peptides in insects. We identified the gene for Relish, a compound Drosophila protein that, like mammalian p105 and p100, contains both a Rel homology domain and an IkappaB-like domain. Relish is strongly induced in infected flies, and it can activate transcription from the Cecropin A1 promoter. A Relish transcript is also detected in early embryos, suggesting that it acts in both immunity and embryogenesis. The presence of a compound Rel protein in Drosophila indicates that similar proteins were likely present in primordial immune systems and may serve unique signaling functions.