IκB kinase (IKK) and Jun N-terminal kinase (Jnk) signaling modules are important in the synthesis of immune effector molecules during innate immune responses against lipopolysaccharide and peptidoglycan. However, the regulatory mechanisms required for specificity and termination of these immune responses are unclear. We show here that crosstalk occurred between the drosophila Jnk and IKK pathways, which led to downregulation of each other's activity. The inhibitory action of Jnk was mediated by binding of drosophila activator protein 1 (AP1) to promoters activated by the transcription factor NF-κB. This binding led to recruitment of the histone deacetylase dHDAC1 to the promoter of the gene encoding the antibacterial protein Attacin-A and to local modification of histone acetylation content. Thus, AP1 acts as a repressor by recruiting the deacetylase complex to terminate activation of a group of NF-κB target genes.
Bibliographical noteFunding Information:
We thank W.J. Lee (Ewha Womans University, Seoul, Korea) for providing immunocompetent SL2 cells; J.L. Imler (Institute de Biologie Moleculaire et Cellulaire, Strasbourg, France) for providing reporter plasmids; and J.M. Park (University of California at San Diego) for helpful advice. BRB-ArrayTools v3.X developed by R. Simon (National Cancer Institutes of Health, Bethesda, Maryland) and A. Peng Lam (EMMES, Rockville, Maryland) were used for microarray analyses. Supported by the Creative Research Initiatives Program of the Korean Ministry of Science and Technology (Y.-J.K.).
All Science Journal Classification (ASJC) codes
- Immunology and Allergy