NLR Family, Pyrin Domain Containing Protein 4 (NLRP4)

NALPs are cytoplasmic proteins that form a subfamily within the larger CATERPILLER protein family. Most short NALPs, such as NALP4, have an N-terminal pyrin (MEFV) domain (PYD), followed by a NACHT domain, a NACHT-associated domain (NAD), and a C-terminal leucine-rich repeat (LRR) region. The long NALP, NALP1, also has a C-terminal extension containing a function to find domain (FIIND) and a caspase recruitment domain (CARD). The predicted 994-amino acid protein has an N-terminal PYD, a central NACHT domain, and 8 tandem C-terminal LRRs. RT-PCR analysis detected highest expression in spleen, followed by placenta, lung, liver, kidney, pancreas, and thymus. Immunoblot analysis revealed wide expression of a 110-kD protein.