A family of cytoplasmic proteins (nucleotide-binding oligomerization domain proteins, NODs, caspase recruitment domain proteins, CARDs) that are pathogen recognition receptors, bind breakdown products of bacterial peptidoglycan, and through receptor-interacting protein 2 (RIP2) stimulate NFκB activation. They have a caspase recruitment domain (CARD domain), a nucleotide-binding domain, and a C-terminal regulatory domain. NOD1 (CARD4, 953 aa) detects a N-acetylglucosamine-N-acetylmuramic acid tripeptide motif found in Gram-negative bacterial peptidoglycan, and has structural similarity to a class of disease-resistance plant proteins that induce localized cell death at the site of pathogen invasion. NOD2 (CARD15) recognizes muramyl dipeptide.
Subjects: Medicine and Health.