title: Innate immunity: regulation of caspases by IAP-dependent ubiquitylation.
abstract: Caspases are widely known as initiators and executioners of cell death. Full activation of caspases leading to cleavage of many cellular substrates was long considered to be a point-of-no-return in the apoptosis pathway. However, it also has been known that activated caspases do not always have the ability to kill, but instead initiate non-apoptotic processes such as cell differentiation or activation of innate immune responses. In this issue of The EMBO Journal, Meinander et al (2012) explore the contribution of polyubiquitination of Dredd, a known initiator caspase, to the activation of innate immunity. The authors show that infection with gram-negative bacteria leads to DIAP2-dependent ubiquitylation of Dredd which in turn is required for processing of Relish (Rel) and expression of antimicrobial peptide (AMP) genes that are indispensable for fighting the infection.
authors.affiliation: German Cancer Research Center, Division of Signaling and Functional Genomic and Heidelberg University, Department of Cell and Molecular Biology, Faculty of Medicine Mannheim, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Falschlehner
authors.forename: Michael
authors.initials: M
authors.lastname: Boutros
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D020169:Caspases / Q000378:metabolism*; D004330:Drosophila / Q000276:immunology*; D029721:Drosophila Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation; D006090:Gram-Negative Bacteria / Q000276:immunology*; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D002352:Carrier Proteins; C111892:DIAP2 protein, Drosophila; D029721:Drosophila Proteins; D051034:Inhibitor of Apoptosis Proteins; C118897:peptidoglycan recognition protein; D020169:Caspases; C431887:dredd protein, Drosophila