NLR family apoptosis inhibitory protein (NAIP)

NLR family apoptosis inhibitory protein (NAIP) is a cytosolic protein belonging to both the NOD-like receptor (NLR) and inhibitor of apoptosis protein (IAP) families, distinguished by the presence of three baculoviral IAP repeat (BIR) domains at its N-terminus[4][7]. NAIP plays dual roles as a direct inhibitor of apoptosis and as a key sensor component of the innate immune system. Biochemically, NAIP directly inhibits effector caspases—principally caspase-3 and caspase-7—thereby blocking apoptosis[2]. It also suppresses apoptosome formation and modulates cell division, accumulating at key mitotic structures such as spindle poles and the cytokinetic bridge[1][3]. As part of the cellular response to pathogens, NAIP binds bacterial components and oligomerizes with NLRC4 to form the NAIP/NLRC4 inflammasome, which in turn activates pro-caspase-1, leading to pyroptosis and pro-inflammatory cytokine maturation[5][7]. Genetic deletion or reduction of NAIP, particularly in combination with the SMN1 gene, is associated with increased severity of spinal muscular atrophy, while changes in NAIP function or expression may influence susceptibility to infections, inflammatory disease, or cancer[3]. There are no currently approved drugs known to directly target NAIP.

Other names

Baculoviral IAP repeat-containing protein 1BIRC1NLRB1Neuronal apoptosis inhibitory proteinpsiNAIP

Direct inhibition of effector caspases (caspase-3, caspase-7), Suppression of apoptosome formation, Activation of inflammasome (recruitment of NLRC4/pro-caspase-1), Regulation of cytokine maturation (IL-1β, IL-18)