XIAP

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.

X-linked inhibitor of apoptosis

Multi-functional protein which regulates not only caspases and apoptosis, but also modulates inflammatory signaling and immunity, copper homeostasis, mitogenic kinase signaling, cell proliferation, as well as cell invasion and metastasis. Acts as a direct caspase inhibitor (PubMed:11257230, PubMed:11257231, PubMed:12620238).
Directly bind to the active site pocket of CASP3 and CASP7 and obstructs substrate entry (PubMed:11257230, PubMed:11257231, PubMed:16352606, PubMed:16916640).
Inactivates CASP9 by keeping it in a monomeric, inactive state (PubMed:12620238).
Acts as an E3 ubiquitin-protein ligase regulating NF-kappa-B signaling and the target proteins for its E3 ubiquitin-protein ligase activity include: RIPK1, MAP3K2/MEKK2, DIABLO/SMAC, AIFM1, CCS and BIRC5/survivin. Ubiquitination of CCS leads to enhancement of its chaperone activity toward its physiologic target, SOD1, rather than proteasomal degradation. Ubiquitination of MAP3K2/MEKK2 and AIFM1 does not lead to proteasomal degradation. Plays a role in copper homeostasis by ubiquitinating COMMD1 and promoting its proteasomal degradation. Can also function as E3 ubiquitin-protein ligase of the NEDD8 conjugation pathway, targeting effector caspases for neddylation and inactivation. Ubiquitinates and therefore mediates the proteosomal degradation of BCL2 in response to apoptosis (PubMed:29020630).
Regulates the BMP signaling pathway and the SMAD and MAP3K7/TAK1 dependent pathways leading to NF-kappa-B and JNK activation. Acts as an important regulator of innate immune signaling via regulation of Nod-like receptors (NLRs). Protects cells from spontaneous formation of the ripoptosome, a large multi-protein complex that has the capability to kill cancer cells in a caspase-dependent and caspase-independent manner. Suppresses ripoptosome formation by ubiquitinating RIPK1 and CASP8. Acts as a positive regulator of Wnt signaling and ubiquitinates TLE1, TLE2, TLE3, TLE4 and AES. Ubiquitination of TLE3 results in inhibition of its interaction with TCF7L2/TCF4 thereby allowing efficient recruitment and binding of the transcriptional coactivator beta-catenin to TCF7L2/TCF4 that is required to initiate a Wnt-specific transcriptional program.

Biological Process cellular response to DNA damage stimulus Source:UniProtKB1 Publication
Biological Process copper ion homeostasis Source:UniProtKB1 Publication
Biological Process inhibition of cysteine-type endopeptidase activity Source:UniProtKB1 Publication
Biological Process inhibition of cysteine-type endopeptidase activity involved in apoptotic process Source:Ensembl
Biological Process negative regulation of apoptotic process Source:UniProtKB1 Publication
Biological Process negative regulation of cysteine-type endopeptidase activity involved in apoptotic process Source:UniProtKB1 Publication
Biological Process negative regulation of tumor necrosis factor-mediated signaling pathway Source:UniProtKB1 Publication
Biological Process neuron apoptotic process Source:Ensembl
Biological Process positive regulation of canonical Wnt signaling pathway Source:UniProtKB1 Publication
Biological Process positive regulation of JNK cascade Source:UniProtKB1 Publication
Biological Process positive regulation of protein linear polyubiquitination Source:UniProtKB1 Publication
Biological Process positive regulation of protein ubiquitination Source:UniProtKB1 Publication
Biological Process regulation of apoptosis involved in tissue homeostasis Source:Ensembl
Biological Process regulation of apoptotic process Source:UniProtKB1 Publication
Biological Process regulation of BMP signaling pathway Source:UniProtKB1 Publication
Biological Process regulation of cell cycle Source:GO_Central1 Publication
Biological Process regulation of cell population proliferation Source:UniProtKB1 Publication
Biological Process regulation of inflammatory response Source:UniProtKB1 Publication
Biological Process regulation of innate immune response Source:UniProtKB1 Publication
Biological Process regulation of nucleotide-binding oligomerization domain containing signaling pathway Source:UniProtKB1 Publication
Biological Process Wnt signaling pathway Source:UniProtKB-KW

Cytoplasm
Nucleus
TLE3 promotes its nuclear localization.

Lymphoproliferative syndrome, X-linked, 2 (XLP2):
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.

S-Nitrosylation down-regulates its E3 ubiquitin-protein ligase activity.
Autoubiquitinated.