Promotes caspase-mediated apoptosis. This proapoptotic activity is mediated predominantly through the activation of caspase-9. May be a component of the inflammasome, a protein complex which also includes NALP2, CARD8 and CASP1 and whose function would be the activation of proinflammatory caspases. Forms complexes with other DAPIN domain-containing proteins. Interacts with CIAS1/PYPAF1 and PYDC1. Widely expressed at low levels. Detected in peripheral blood leukocytes, lung, small intestine, spleen, thymus, colon and at lower levels in placenta, liver and kidney. Very low expression in skeletal muscle, heart and brain. Detected in the leukemia cell lines HL-60 and U-937, but not in Jurkat T- cell lymphoma and Daudi Burkitt's lymphoma. Detected in the melanoma cell line WM35, but not in WM793. Not detected in HeLa cervical carcinoma cells and MOLT-4 lymphocytic leukemia cells. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Molecular Function: protein binding; protein homodimerization activity; cysteine-type endopeptidase activity; caspase activator activity; Pyrin domain binding
Biological Process: myeloid dendritic cell activation during immune response; positive regulation of apoptosis; regulation of protein stability; positive regulation of JNK cascade; positive regulation of caspase activity; positive regulation of interleukin-1 beta secretion; defense response to Gram-negative bacterium; signal transduction; proteolysis; positive regulation of activated T cell proliferation; activation of NF-kappaB transcription factor; tumor necrosis factor-mediated signaling pathway; positive regulation of phagocytosis; inflammatory response; defense response to virus; DNA damage response, signal transduction by p53 class mediator resulting in induction of apoptosis; positive regulation of adaptive immune response; caspase activation; positive regulation of interleukin-6 production; negative regulation of I-kappaB kinase/NF-kappaB cascade; positive regulation of tumor necrosis factor production; negative regulation of interferon-beta production; myeloid dendritic cell activation; positive regulation of interferon-gamma production; positive regulation of actin filament polymerization; inhibition of NF-kappaB transcription factor; induction of apoptosis; innate immune response; positive regulation of transcription factor activity; positive regulation of T cell activation; activation of innate immune response; positive regulation of antigen processing and presentation of peptide antigen via MHC class II
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.