Stoven, SvenjaSilverman, NealJunell, AnnaHedengren-Olcott, MarikaErturk Hasdemir, DenizEngstrom, YlvaManiatis, TomHultmark, Dan2022-08-232022-08-232003-05-072008-12-19Proc Natl Acad Sci U S A. 2003 May 13;100(10):5991-6. Epub 2003 May 5. <a href="http://dx.doi.org/10.1073/pnas.1035902100">Link to article on publisher's site</a>0027-8424 (Print)10.1073/pnas.103590210012732719https://hdl.handle.net/20.500.14038/34925The NF-kappaB-like transcription factor Relish plays a central role in the innate immune response of Drosophila. Unlike other NF-kappaB proteins, Relish is activated by endoproteolytic cleavage to generate a DNA-binding Rel homology domain and a stable IkappaB-like fragment. This signal-induced endoproteolysis requires the activity of several gene products, including the IkappaB kinase complex and the caspase Dredd. Here we used mutational analysis and protein microsequencing to demonstrate that a caspase target site, located in the linker region between the Rel and the IkappaB-like domain, is the site of signal-dependent cleavage. We also show physical interaction between Relish and Dredd, suggesting that Dredd indeed is the Relish endoprotease. In addition to the caspase target site, the C-terminal 107 aa of Relish are required for endoproteolysis and signal-dependent phosphorylation by the Drosophila IkappaB kinase beta. Finally, an N-terminal serine-rich region in Relish and the PEST domain were found to negatively regulate Relish activation.en-USAnimalsBase SequenceCaspasesCells, CulturedChloramphenicol O-AcetyltransferaseDNA PrimersDrosophila ProteinsDrosophila melanogasterGene DeletionGene Expression RegulationGenes, ReporterKineticsMolecular Sequence DataPhosphorylationPolymerase Chain ReactionSequence DeletionTranscription Factorsbeta-GalactosidaseImmunology and Infectious DiseaseJournal Articlehttps://escholarship.umassmed.edu/infdis_pp/15684326infdis_pp/15