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fat facets induces polyubiquitination of Imd and inhibits the innate immune response in D rosophila
Author(s) -
Yagi Yoshimasa,
Lim YoungMi,
Tsuda Leo,
Nishida Yasuyoshi
Publication year - 2013
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/gtc.12085
Subject(s) - biology , ubiquitin , innate immune system , deubiquitinating enzyme , immune system , microbiology and biotechnology , gene , mutant , genetic screen , genetics
The IMD pathway is one of the major regulators of the innate immune response in D rosophila . Although extensive analysis of the IMD pathway has been carried out, precise mechanisms for how each target gene of the pathway is down‐regulated remain to be clarified. Here, we carried out genetic screening and found that fat facets ( faf ), which encodes a deubiquitinating enzyme, inhibited the expression of the target genes of the IMD pathway. Overexpression of faf suppressed the infection‐induced expression of Diptericin and increased susceptibility to bacterial infection in flies, whereas faf loss‐of‐function mutants decreased susceptibility. Time course analysis revealed that specific subsets of the target genes of the IMD pathway were affected by faf . Biochemical analysis showed that F af made a complex with Imd, and both F af and Imd were polyubiquitinated when they were co‐overexpressed. Given that faf ‐dependent Imd polyubiquitination did not seem to cause protein degradation of Imd, F af might inhibit the IMD pathway by modulating the state of Imd ubiquitination and/or stability.