TY - JOUR
T1 - The role of ubiquitination in Drosophila innate immunity
AU - Zhou, Rui
AU - Silverman, Neal
AU - Hong, Mei
AU - Liao, Dorothy S.
AU - Chung, Yvonne
AU - Chen, Zhijian J.
AU - Maniatis, Tom
PY - 2005/10/7
Y1 - 2005/10/7
N2 - Infection of Drosophila by Gram-negative bacteria triggers a signal transduction pathway (the IMD pathway) culminating in the expression of genes encoding antimicrobial peptides. A key component in this pathway is a Drosophila IκB kinase (DmIKK) complex, which stimulates the cleavage and activation of the NF-κB transcription factor Relish. Activation of the DmIKK complex requires the MAP3K dTAK1, but the mechanism of dTAK1 activation is not understood. In human cells, the activation of TAK1 and IKK requires the human ubiquitin-conjugating enzymes Ubc13 and UEV1a. Here we demonstrate that the Drosophila homologs of Ubc13 and UEV1a are similarly required for the activation of dTAK1 and the DmIKK complex. Surprisingly, we find that the Drosophila caspase DREDD and its partner dFADD are required for the activation of DmIKK and JNK, in addition to their role in Relish cleavage. These studies reveal an evolutionarily conserved role of ubiquitination in IKK activation, and provide new insights into the hierarchy of signaling components in the Drosophila antibacterial immunity pathway.
AB - Infection of Drosophila by Gram-negative bacteria triggers a signal transduction pathway (the IMD pathway) culminating in the expression of genes encoding antimicrobial peptides. A key component in this pathway is a Drosophila IκB kinase (DmIKK) complex, which stimulates the cleavage and activation of the NF-κB transcription factor Relish. Activation of the DmIKK complex requires the MAP3K dTAK1, but the mechanism of dTAK1 activation is not understood. In human cells, the activation of TAK1 and IKK requires the human ubiquitin-conjugating enzymes Ubc13 and UEV1a. Here we demonstrate that the Drosophila homologs of Ubc13 and UEV1a are similarly required for the activation of dTAK1 and the DmIKK complex. Surprisingly, we find that the Drosophila caspase DREDD and its partner dFADD are required for the activation of DmIKK and JNK, in addition to their role in Relish cleavage. These studies reveal an evolutionarily conserved role of ubiquitination in IKK activation, and provide new insights into the hierarchy of signaling components in the Drosophila antibacterial immunity pathway.
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U2 - 10.1074/jbc.M506655200
DO - 10.1074/jbc.M506655200
M3 - Article
C2 - 16081424
AN - SCOPUS:26644432726
SN - 0021-9258
VL - 280
SP - 34048
EP - 34055
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 40
ER -