Apoptoosin

Apoptoosin is a term used in some educational and speculative discussions to describe a hypothetical pro-apoptotic protein involved in the intrinsic apoptosis pathway. It is not a recognized protein with an established gene, sequence, or structural data in peer-reviewed databases, and no experimental evidence currently confirms its existence.

Conceptually, apoptoosin is described as a mitochondrial-associated factor that, under cellular stress, promotes mitochondrial outer membrane permeabilization (MOMP). In proposed models, it would interact with BCL-2 family proteins such as Bax and Bak to facilitate cytochrome c release into the cytosol, leading to apoptosome assembly and activation of initiator caspases and downstream effector caspases.

In educational contexts, apoptoosin serves to illustrate how a single pro-apoptotic mediator could influence cell fate and how redundancy and regulation in the apoptotic network contribute to decisive outcomes. The term is often presented with caveats that it remains hypothetical and not established as a real protein, and readers are reminded of the distinction between teaching examples and verified biology.

See also: Apoptosis; Mitochondrial outer membrane permeabilization; Apoptosome; Caspases; Bax; Bak.