BH3-interacting domain death agonist (tBID) (tBID)

BH3-interacting domain death agonist (BID) is a pro-apoptotic member of the Bcl-2 protein family that serves as a critical link between the extrinsic and intrinsic apoptotic pathways (UniProt: P55957). In its inactive form, BID resides in the cytosol; however, upon activation of death receptors, it is cleaved by caspase-8 to form its active, truncated version known as tBID (PubMed: 9671300). Once formed, tBID translocates to the outer mitochondrial membrane where it directly activates the pore-forming proteins BAX and BAK, or neutralizes anti-apoptotic proteins like Bcl-2 and Bcl-xL (PubMed: 10581237). This process results in mitochondrial outer membrane permeabilization (MOMP), the release of cytochrome c, and subsequent cell death (PubMed: 11713533). Because of its central role in regulating apoptosis, tBID is a significant focus in oncology, where its downregulation often contributes to chemoresistance (PubMed: 15607512). Conversely, inhibiting tBID has been explored as a strategy to prevent pathological cell death in conditions such as stroke or myocardial infarction (PubMed: 11590439).

Other names

BIDp15 BIDp13 BIDHuman BIDBH3-interacting domain death agonist

tBID functions as a death agonist by inducing mitochondrial outer membrane permeabilization (MOMP). Therapeutic strategies involve either inhibiting tBID to prevent cell death in ischemic or neurodegenerative conditions, or utilizing BH3 mimetics to replicate tBID's function and induce apoptosis in cancer cells by antagonizing anti-apoptotic Bcl-2 proteins and directly activating BAX and BAK (PubMed: 10581237, PubMed: 17430381).