Mutational analysis of human NOD1 and NOD2 NACHT domains reveals different modes of activation

Abstract

Nucleotide-binding oligomerization domain-containing protein (NOD)1 and NOD2 are intracellular pattern recognition receptors (PRRs) of the nucleotide-binding domain and leucine-rich repeat containing (NLR) gene family involved in innate immune responses. Their centrally located NACHT domain displays ATPase activity and is necessary for activation and oligomerization leading to inflammatory signaling responses. Mutations affecting key residues of the ATPase domain of NOD2 are linked to severe auto-inflammatory diseases, such as Blau syndrome and early-onset sarcoidosis. By mutational dissection of the ATPase domain function, we show that the NLR-specific extended Walker B box (DGhDE) can functionally replace the canonical Walker B sequence (DDhWD) found in other ATPases. A requirement for an intact Walker A box and the magnesium-co-ordinating aspartate of the classical Walker B box suggest that an initial ATP hydrolysis step is necessary for activation of both NOD1 and NOD2. In contrast, a Blau-syndrome associated mutation located in the extended Walker B box of NOD2 that results in higher autoactivation and ligand-induced signaling does not affect NOD1 function. Moreover, mutation of a conserved histidine in the NACHT domain also has contrasting effects on NOD1 and NOD2 mediated NF-κB activation. We conclude that these two NLRs employ different modes of activation and propose distinct models for activation of NOD1 and NOD2.

Signal Transduction by a Fungal NOD-Like Receptor Based on Propagation of a Prion Amyloid Fold

“…We reasoned that inactivation of ATP/ADP binding should affect [Het-s]-inducing activity of NWD2. We generated four point mutants (K83N, K83R, D178A, and R214S) affecting respectively the P-loop motif (Walker A), the Walker B motif and the Sensor I region of the NACHT domain [49,50]. The position corresponding to the Sensor I was deduced from sequence alignment and a homology model to APAF-1.…”

A Case of Blau Syndrome

“…The carboxyl terminal region is the sensory region, consists of leucine rich repeat region (LRR); it mediates protein-protein interactions and pattern recognition of various pathogens and host molecules, [6, 7]. Central domain is the nucleotide binding and oligomerization (NACHT) domain which is responsible for oligomerization, formation of high molecular weight complexes, and subsequent activation of NOD2.…”

Formation and Structure of a NAIP5-NLRC4 Inflammasome Induced by Direct Interactions with Conserved N- and C-terminal Regions of Flagellin

“…The Role of ATP Binding in Inflammasome Formation-It has been suggested that ATP binding by NLRs is essential for their oligomerization (16 -18), as well as for responsiveness to their specific ligand (20). The reconstitution of a NAIP5-NLRC4 inflammasome in the presence of EDTA (Fig.…”