Abstract
Both plants and animals respond to infection by synthesizing compounds that directly inhibit or kill invading pathogens. We report here the identification of infection-inducible antimicrobial peptides in Caenorhabditis elegans. Expression of two of these peptides, NLP-29 and NLP-31, was differentially regulated by fungal and bacterial infection and was controlled in part by tir-1, which encodes an ortholog of SARM, a Toll-interleukin 1 receptor (TIR) domain protein. Inactivation of tir-1 by RNA interference caused increased susceptibility to infection. We identify protein partners for TIR-1 and show that the small GTPase Rab1 and the f subunit of ATP synthase participate specifically in the control of antimicrobial peptide gene expression. As the activity of tir-1 was independent of the single nematode Toll-like receptor, TIR-1 may represent a component of a previously uncharacterized, but conserved, innate immune signaling pathway.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Amino Acid Sequence
-
Animals
-
Antimicrobial Cationic Peptides / genetics
-
Antimicrobial Cationic Peptides / metabolism
-
Armadillo Domain Proteins
-
Caenorhabditis elegans / immunology*
-
Caenorhabditis elegans / metabolism
-
Caenorhabditis elegans / microbiology
-
Caenorhabditis elegans Proteins / genetics
-
Caenorhabditis elegans Proteins / metabolism*
-
Cytoskeletal Proteins / genetics
-
Cytoskeletal Proteins / metabolism*
-
Immunity, Innate / genetics
-
Immunity, Innate / immunology*
-
Membrane Glycoproteins / metabolism
-
Molecular Sequence Data
-
Mycoses / immunology
-
Mycoses / metabolism
-
Receptors, Cell Surface / metabolism
-
Receptors, G-Protein-Coupled
-
Toll-Like Receptors
Substances
-
Antimicrobial Cationic Peptides
-
Armadillo Domain Proteins
-
Caenorhabditis elegans Proteins
-
Cytoskeletal Proteins
-
Membrane Glycoproteins
-
Receptors, Cell Surface
-
Receptors, G-Protein-Coupled
-
SARM1 protein, human
-
Toll-Like Receptors
-
tir-1 protein, C elegans