| This gene encodes a protein that belongs to a family of apoptotic suppressor proteins. Members of this family share a conserved motif termed, baculovirus IAP repeat, which is necessary for their anti-apoptotic function. This protein functions through binding to tumor necrosis factor receptor-associated factors TRAF1 and TRAF2 and inhibits apoptosis induced by menadione, a potent inducer of free radicals, and interleukin 1-beta converting enzyme. This protein also inhibits at least two members of the caspase family of cell-death proteases, caspase-3 and caspase-7. Mutations in this gene are the cause of X-linked lymphoproliferative syndrome. Alternate splicing results in multiple transcript variants. Pseudogenes of this gene are found on chromosomes 2 and 11.[provided by RefSeq, Feb 2011],disease:Defects in XIAP are the cause of lymphoproliferative syndrome X-linked type 2 (XLP2) [MIM:300635]. XLP is a rare immunodeficiency characterized by extreme susceptibility to infection with Epstein-Barr virus (EBV). Symptoms include severe or fatal mononucleosis, acquired hypogammaglobulinemia, pancytopenia and malignant lymphoma.,domain:The first BIR domain is involved in interaction with MAP3K7IP1 and is important for dimerization. The second BIR domain is sufficient to inhibit caspase-3 and caspase-7, while the third BIR is involved in caspase-9 inhibition. The interactions with SMAC and PRSS25 are mediated by the second and third BIR domains.,function:Apoptotic suppressor. Has E3 ubiquitin-protein ligase activity. Mediates the proteasomal degradation of target proteins, such as caspase-3, SMAC or AIFM1. Inhibitor of caspase-3, -7 and -9. Mediates activation of MAP3K7/TAK1, leading to the activation of NF-kappa-B.,online information:XIAP mutation db,PTM:Phosphorylation by PKB/AKT protects XIAP against ubiquitination and protects the protein against proteasomal degradation.,PTM:Ubiquitinated and degraded by the proteasome in apoptotic cells.,similarity:Belongs to the IAP family.,similarity:Contains 1 RING-type zinc finger.,similarity:Contains 3 BIR repeats.,subunit:Monomer, and homodimer. Interacts with SMAC and with PRSS25, these interactions inhibit apoptotic suppressor activity. Interacts with MAP3K7IP1 and AIFM1. Interaction with SMAC hinders binding of MAP3K7IP1 and AIFM1. Interacts with TCF25.,tissue specificity:Ubiquitous, except peripheral blood leukocytes., |
