This family consists of several mammalian specific BCL2/adenovirus E1B 19-kDa protein-interacting protein 3 or BNIP3 sequences. BNIP3 belongs to the Bcl-2 homology 3 (BH3)-only family, a Bcl-2-related family possessing an atypical Bcl-2 homology 3 (BH3) domain, which regulates PCD from mitochondrial sites by selective Bcl-2/Bcl-XL interactions. BNIP3 family members contain a C-terminal transmembrane domain that is required for their mitochondrial localisation, homodimerisation, as well as regulation of their pro-apoptotic activities. BNIP3-mediated apoptosis has been reported to be independent of caspase activation and cytochrome c release and is characterised by early plasma membrane and mitochondrial damage, prior to the appearance of chromatin condensation or DNA fragmentation [1].

1: CD47 and the 19 kDa interacting protein-3 (BNIP3) in T cell apoptosis. Lamy L, Ticchioni M, Rouquette-Jazdanian AK, Samson M, Deckert M, Greenberg AH, Bernard A; J Biol Chem 2003;278:23915-23921. PMID:12690108