B-cell lymphoma 2 (Bcl-2) family protein-protein interactions (Bcl-2 family PPIs)

The B-cell lymphoma 2 (Bcl-2) family of proteins serves as a critical "apoptotic rheostat" that governs the intrinsic pathway of programmed cell death [1]. This family is divided into three functional groups: anti-apoptotic members (e.g., Bcl-2, Bcl-xL, Mcl-1), pro-apoptotic effectors (Bax, Bak), and pro-apoptotic BH3-only initiators (e.g., Bim, Bid, Puma) [2]. In many cancers, the overexpression of anti-apoptotic proteins allows malignant cells to evade death by sequestering pro-apoptotic proteins through specific protein-protein interactions (PPIs) [3]. Therapeutic strategies, most notably BH3 mimetics like Venetoclax, target these PPIs by binding to the hydrophobic grooves of anti-apoptotic proteins, thereby releasing the pro-apoptotic "brakes" and inducing mitochondrial outer membrane permeabilization [4]. While highly effective in hematologic malignancies, challenges include managing tumor lysis syndrome and overcoming resistance mechanisms such as the upregulation of alternative anti-apoptotic family members like Mcl-1 [5].

Other names

Bcl-2 family proteinsB-cell CLL/lymphoma 2 familyApoptotic rheostat

BH3 mimetics competitively bind to the hydrophobic groove of anti-apoptotic Bcl-2 family members (e.g., Bcl-2, Bcl-xL, Mcl-1), displacing pro-apoptotic BH3-only proteins or effectors like Bax/Bak to trigger mitochondrial outer membrane permeabilization and apoptosis [1][2][4].