Sci. STKE, 1 February 2005
IMMUNOLOGY Delineating a Pathogen Response Pathway in Drosophila
Host organisms initiate a defense response to bacterial infection through innate immune receptors that recognize microbial molecules. In Drosophila, a transmembrane protein of the peptidoglycan-recognition protein family called PGRP-LC responds to certain microbial peptides by initiating a signaling cascade that activates genes with antibacterial action. Although genetic analysis suggests that the pathway involves the death-domain protein Imd and Relish, a transcription factor of the NF-B family, molecular details of the cascade have not been determined. By expressing PGRP-LC in cultured Drosophila cells, Choe et al. found that the receptor requires its membrane-proximal cytoplasmic region either to homodimerize or to form heterodimers with other receptor isoforms. Expression of PGRP-LC and Imd deletion mutants revealed interaction between the receptor cytoplasmic tail and the N terminus of Imd, although the interaction may not be direct. The pathway appears similar to a signaling pathway initiated by mammalian Toll-like receptors that likewise function in pathogen recognition and also form a complex with the death-domain protein MyD88 to activate an IB kinase complex.
K.-M. Choe, H. Lee, K. V. Anderson, Drosophila peptidoglycan recognition protein LC (PGRP-LC) acts as a signal-transducing innate immune receptor. Proc. Natl. Acad. Sci. U.S.A. 102, 1122-1126 (2005). [Abstract] [Full Text]
Citation: Delineating a Pathogen Response Pathway in Drosophila. Sci. STKE 2005, tw44 (2005).
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