Accelerates programmed cell death by binding to, and antagonizing the apoptosis repressor BCL2 or its adenovirus homolog E1B 19k protein. Under stress conditions, undergoes a conformation change that causes translocation to the mitochondrion membrane, leading to the release of cytochrome c that then triggers apoptosis. Promotes activation of CASP3, and thereby apoptosis. Homodimer. Forms higher oligomers under stress conditions. Interacts with BCL2L11. Interaction with BCL2L11 promotes BAX oligomerization and association with mitochondrial membranes, with subsequent release of cytochrome c. Forms heterodimers with BCL2, E1B 19K protein, BCL2L1 isoform Bcl-X(L), BCL2L2, MCL1 and A1. Interacts with SH3GLB1 and HN. Interacts with SFN and YWHAZ; the interaction occurs in the cytoplasm. Under stress conditions, JNK-mediated phosphorylation of SFN and YWHAZ, releases BAX to mitochondria. Isoform Sigma interacts with BCL2A1 and BCL2L1 isoform Bcl-X(L). Interacts with RNF144B, which regulates the ubiquitin-dependent stability of BAX. Interacts with CLU under stress conditions that cause a conformation change leading to BAX oligomerization and association with mitochondria. Does not interact with CLU in unstressed cells. Interacts with FAIM2/LFG2. Interacts with human cytomegalovirus/HHV-5 protein vMIA/UL37. Expressed in a wide variety of tissues. Isoform Psi is found in glial tumors. Isoform Alpha is expressed in spleen, breast, ovary, testis, colon and brain, and at low levels in skin and lung. Isoform Sigma is expressed in spleen, breast, ovary, testis, lung, colon, brain and at low levels in skin. Isoform Alpha and isoform Sigma are expressed in pro- myelocytic leukemia, histiocytic lymphoma, Burkitt's lymphoma, T- cell lymphoma, lymphoblastic leukemia, breast adenocarcinoma, ovary adenocarcinoma, prostate carcinoma, prostate adenocarcinoma, lung carcinoma, epidermoid carcinoma, small cell lung carcinoma and colon adenocarcinoma cell lines. Belongs to the Bcl-2 family. 8 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Apoptosis; Mitochondrial; Membrane protein, integral
Molecular Function: identical protein binding; protein binding; protein homodimerization activity; channel activity; protein heterodimerization activity; BH3 domain binding; lipid binding
Biological Process: hypothalamus development; viral reproduction; positive regulation of apoptosis; regulation of cell cycle; response to toxin; myeloid cell homeostasis; germ cell programmed cell death; nuclear fragmentation during apoptosis; B cell apoptosis; germ cell development; regulation of mammary gland epithelial cell proliferation; spermatid differentiation; development of secondary sexual characteristics; regulation of mitochondrial membrane potential; protein insertion into mitochondrial membrane during induction of apoptosis; establishment and/or maintenance of transmembrane electrochemical gradient; negative regulation of neuron apoptosis; negative regulation of protein binding; kidney development; release of cytochrome c from mitochondria; positive regulation of B cell apoptosis; regulation of protein homodimerization activity; vagina development; protein oligomerization; fertilization; DNA damage response, signal transduction resulting in induction of apoptosis; induction of apoptosis via death domain receptors; retina development in camera-type eye; negative regulation of fibroblast proliferation; reduction of endoplasmic reticulum calcium ion concentration; glycosphingolipid metabolic process; mitochondrial fragmentation during apoptosis; cerebral cortex development; regulation of nitrogen utilization; post-embryonic camera-type eye morphogenesis; positive regulation of pigmentation; regulation of protein heterodimerization activity; apoptosis; T cell homeostatic proliferation; neuron migration; negative regulation of peptidyl-serine phosphorylation; positive regulation of apoptosis involved in mammary gland involution; release of matrix enzymes from mitochondria; response to salt stress; positive regulation of protein oligomerization; apoptotic mitochondrial changes; B cell homeostatic proliferation; ovarian follicle development; B cell homeostasis; positive regulation of neuron apoptosis; response to gamma radiation; response to axon injury; B cell negative selection; protein homooligomerization; caspase activation; transformed cell apoptosis; mitochondrial fusion; Sertoli cell proliferation; odontogenesis of dentine-containing teeth; neuron apoptosis; endoplasmic reticulum calcium ion homeostasis; homeostasis of number of cells within a tissue; blood vessel remodeling; retinal cell programmed cell death; caspase activation via cytochrome c; positive regulation of release of sequestered calcium ion into cytosol; response to acid
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.