FEATURES

FAMILY

DESCRIPTION

Also known as NLRP6_HUMAN, NLRP6, NALP6, PYPAF5. As the sensor component of the NLRP6 inflammasome, plays a crucial role in innate immunity and inflammation. In response to pathogens and other damage-associated signals, initiates the formation of the inflammasome polymeric complex, made of NLRP6, PYCARD and CASP1 (and possibly CASP4 and CASP5). Recruitment of proCASP1 to the inflammasome promotes its activation and CASP1-catalyzed IL1B and IL18 maturation and secretion in the extracellular milieu. The precise NLRP6 activation stimulus has not been identified yet (By similarity) (PubMed:12387869). Essential for gut mucosal self-renewal and proliferation. Maintains intestinal homeostasis and a healthy intestinal microbiota. This function is, at least partially, mediated by IL18, and not IL1B, produced by nonhematopoietic cells. Influences intestinal barrier function and microbial homeostasis through the regulation of goblet cell mucus secretion. Acts by promoting autophagy in goblet cells, an essential step for mucus granule exocytosis. Its role in goblet cell physiology is inflammasome-dependent, but IL1B- and IL18-independent. During systemic bacterial infections, may negatively regulate inflammatory signaling and inhibit the influx of monocytes and neutrophils to the circulation and to the peritoneum. May promote peripheral nerve recovery following injury via an inflammasome-independent mechanism (By similarity). Sensor component of NLRP6 inflammasomes. Inflammasomes are supramolecular complexes that assemble in the cytosol in response to pathogens and other damage-associated signals and play critical roles in innate immunity and inflammation. The core of NLRP6 inflammasomes consists of a signal sensor component (NLRP6), an adapter (ASC/PYCARD), which recruits an effector proinflammatory caspase (CASP1 and, possibly, CASP4 and CASP5). Within the complex, NLRP6 and PYCARD interact via their respective pyrin domains. This interaction initiates speck formation (nucleation) which greatly enhances further addition of soluble PYCARD molecules to the speck in a prion-like polymerization process. NLRP6 localizes at the end of each PYCARD filament. Clustered PYCARD nucleates the formation of CASP1 filaments through the interaction of their respective CARD domains, acting as a platform for CASP1 polymerization. CASP1 filament formation increases local enzyme concentration, resulting in trans-autocleavage and activation. Active CASP1 then processes IL1B and IL18 precursors, leading to the release of mature cytokines in the extracellular milieu and inflammatory response. In this complex, the sensor protein is sub-stoichiometric to PYCARD, and PYCARD is further substoichiometric to CASP1, suggesting amplifications of signal transduction from the sensor, via the adapter, to the effector.

EXTERNAL LINKS

NLRP6

NACHT, LRR and PYD domains-containing protein 6

NLRP6

Molecular Synopsis