FunctionThe major proteolytic product p15 BID allows the release of cytochrome c (By similarity). Isoform 1, isoform 2 and isoform 4 induce ICE-like proteases and apoptosis. Isoform 3 does not induce apoptosis. Counters the protective effect of Bcl-2.
Tissue specificityIsoform 2 and isoform 3 are expressed in spleen, bone marrow, cerebral and cerebellar cortex. Isoform 2 is expressed in spleen, pancreas and placenta (at protein level). Isoform 3 is expressed in lung, pancreas and spleen (at protein level). Isoform 4 is expressed in lung and pancreas (at protein level).
DomainIntact BH3 motif is required by BIK, BID, BAK, BAD and BAX for their pro-apoptotic activity and for their interaction with anti-apoptotic members of the Bcl-2 family.
Post-translational modificationsTNF-alpha induces a caspase-mediated cleavage of p22 BID into a major p15 and minor p13 and p11 products. Phosphorylated upon DNA damage, probably by ATM or ATR. p15 BID is ubiquitinated by ITCH; ubiquitination results in proteasome-dependent degradation.
Cellular localizationCytoplasm; Cytoplasm. Mitochondrion membrane. When uncleaved, it is predominantly cytoplasmic; Mitochondrion membrane. A significant proportion of isoform 2 localizes to mitochondria, it may be cleaved constitutively; Mitochondrion membrane. Associated with the mitochondrial membrane and Mitochondrion membrane. Translocates to mitochondria as an integral membrane protein.