期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：17
页码：6593-6598
DOI：10.1073/pnas.0308625101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The p38 mitogen-activated protein kinase pathway regulates innate immune responses in evolutionarily diverse species. We have previously shown that the Caenorhabditis elegans p38 mitogen-activated protein kinase, PMK-1, functions in an innate immune response pathway that mediates resistance to a variety of microbial pathogens. Here, we show that tir-1, a gene encoding a highly conserved Toll/IL-1 resistance (TIR) domain protein, is also required for C. elegans resistance to microbial pathogens. RNA interference inactivation of tir-1 resulted in enhanced susceptibility to killing by pathogens and correspondingly diminished PMK-1 phosphorylation. Unlike all known TIR-domain adapter proteins, overexpression of the human TIR-1 homologue, SARM, in mammalian cells was not sufficient to induce expression of NF-{kappa}B or IRF3-dependent reporter genes that are activated by Toll-like receptor signaling. These data reveal the involvement of a previously uncharacterized, evolutionarily conserved TIR domain protein in innate immunity that is functionally distinct from other known TIR domain signaling adapters.
