Plays a role in the mitochondrial apoptotic process. Under normal conditions, BAX is largely cytosolic via constant retrotranslocation from mitochondria to the cytosol mediated by BCL2L1/Bcl-xL, which avoids accumulation of toxic BAX levels at the mitochondrial outer membrane (MOM). 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. Belongs to the Bcl-2 family. 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. 2 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Apoptosis; Membrane protein, integral; Mitochondrial; Tumor suppressor
Cellular Component: BAX complex; Bcl-2 family protein complex; cytoplasm; cytosol; endoplasmic reticulum; endoplasmic reticulum membrane; integral component of membrane; membrane; mitochondrial membrane; mitochondrial outer membrane; mitochondrial permeability transition pore complex; mitochondrion; nuclear envelope; nucleus; perinuclear region of cytoplasm; pore complex
Molecular Function: BH domain binding; BH3 domain binding; channel activity; chaperone binding; heat shock protein binding; Hsp70 protein binding; identical protein binding; lipid binding; protein binding; protein heterodimerization activity; protein homodimerization activity; protein-containing complex binding
Biological Process: activation of cysteine-type endopeptidase activity involved in apoptotic process; activation of cysteine-type endopeptidase activity involved in apoptotic process by cytochrome c; activation of cysteine-type endopeptidase activity involved in apoptotic signaling pathway; apoptotic mitochondrial changes; apoptotic process; apoptotic process involved in blood vessel morphogenesis; apoptotic process involved in embryonic digit morphogenesis; apoptotic signaling pathway; B cell apoptotic process; B cell homeostasis; B cell homeostatic proliferation; B cell negative selection; B cell receptor apoptotic signaling pathway; blood vessel remodeling; cell proliferation; cellular respiration; cellular response to DNA damage stimulus; cellular response to organic substance; cellular response to UV; cerebral cortex development; development of secondary sexual characteristics; ectopic germ cell programmed cell death; establishment or maintenance of transmembrane electrochemical gradient; extrinsic apoptotic signaling pathway; extrinsic apoptotic signaling pathway in absence of ligand; extrinsic apoptotic signaling pathway via death domain receptors; fertilization; germ cell development; glycosphingolipid metabolic process; homeostasis of number of cells; homeostasis of number of cells within a tissue; hypothalamus development; inner mitochondrial membrane organization; intrinsic apoptotic signaling pathway; intrinsic apoptotic signaling pathway by p53 class mediator; intrinsic apoptotic signaling pathway in response to DNA damage; intrinsic apoptotic signaling pathway in response to endoplasmic reticulum stress; kidney development; leukocyte homeostasis; limb morphogenesis; male gonad development; mitochondrial fragmentation involved in apoptotic process; mitochondrial fusion; mitochondrion morphogenesis; myeloid cell homeostasis; negative regulation of apoptotic signaling pathway; negative regulation of cell proliferation; negative regulation of endoplasmic reticulum calcium ion concentration; negative regulation of fibroblast proliferation; negative regulation of mitochondrial membrane potential; negative regulation of neuron apoptotic process; negative regulation of peptidyl-serine phosphorylation; negative regulation of protein binding; nervous system development; neuron apoptotic process; neuron migration; odontogenesis of dentin-containing tooth; outer mitochondrial membrane organization; ovarian follicle development; positive regulation of apoptotic DNA fragmentation; positive regulation of apoptotic process; positive regulation of apoptotic process involved in mammary gland involution; positive regulation of B cell apoptotic process; positive regulation of calcium ion transport into cytosol; positive regulation of developmental pigmentation; positive regulation of endoplasmic reticulum unfolded protein response; positive regulation of extrinsic apoptotic signaling pathway in absence of ligand; positive regulation of intrinsic apoptotic signaling pathway; positive regulation of mitochondrial membrane permeability involved in apoptotic process; positive regulation of neuron apoptotic process; positive regulation of protein oligomerization; positive regulation of release of cytochrome c from mitochondria; positive regulation of release of sequestered calcium ion into cytosol; post-embryonic camera-type eye morphogenesis; post-embryonic development; protein complex oligomerization; protein homooligomerization; protein insertion into mitochondrial membrane involved in apoptotic signaling pathway; regulation of apoptotic process; regulation of cell cycle; regulation of cysteine-type endopeptidase activity involved in apoptotic process; regulation of mammary gland epithelial cell proliferation; regulation of mitochondrial membrane permeability involved in apoptotic process; regulation of mitochondrial membrane permeability involved in programmed necrotic cell death; regulation of neuron apoptotic process; regulation of nitrogen utilization; regulation of protein heterodimerization activity; regulation of protein homodimerization activity; release of cytochrome c from mitochondria; release of matrix enzymes from mitochondria; response to axon injury; response to gamma radiation; response to ionizing radiation; response to salt stress; response to toxic substance; response to wounding; retina development in camera-type eye; retinal cell programmed cell death; Sertoli cell proliferation; sex differentiation; spermatid differentiation; spermatogenesis; T cell homeostatic proliferation; thymocyte apoptotic process; vagina development; viral process