REL: Relish-like Proteins
Summary

Sang Woon Shin, Guowu Bian, Kanwal Alvarez, and Alexander Raikhel 

Department of Entomology and the Institute for Integrative Genome Biology, University of California, Riverside California 92521, USA 

Upon activation in Drosophila, Toll-1 recruits a cascade of signalling adaptors and kinases resulting in Cactus phosphorylation and the release and subsequent nuclear translocation of the REL transcription factors, Dorsal and Dif. AgREL1, AaREL1A and AaREL1B represent an orthologous group to DmDorsal [Barillas-Mury et al 1996; Shin et al 2005]. The AaREL1B gene appears to be intronless and may have originated by retrotransposition. AaREL1B and AaTOLL1B are expressed only at early embryonic stages, and thus may be functionally linked (Shin S.W., unpublished data). Transgenic analysis has shown that the REL1A/CACT cassette controls Aedes anti-fungal responses, similar to Dif/Cactus in Dm [Bian 2005]. This is an interesting case of functional transfer between paralogs: REL1A is in the orthologous group of Dorsal rather than Dif, which is absent from the mosquito lineage.