Bcl-2-like protein 1 (Bcl-xL (primary anti-apoptotic isoform), Bcl-xS (alternative pro-apoptotic isoform))

Bcl-2-like protein 1 is a key member of the Bcl-2 protein family, encoded by the BCL2L1 gene in humans. It regulates apoptosis by controlling the mitochondrial outer membrane's permeability through interactions with voltage-dependent anion channels (VDACs), affecting cytochrome C release. Through alternative splicing, BCL2L1 produces both anti-apoptotic (Bcl-xL) and pro-apoptotic (Bcl-xS) protein isoforms. Bcl-xL is potently anti-apoptotic and critical for the survival of post-mitotic neurons and platelets, while Bcl-xS promotes apoptosis. Overexpression of Bcl-xL is implicated in cancer cell resistance to therapy, making it an important therapeutic target. Inhibitors known as BH3-mimetics (e.g., navitoclax) have been developed to target its anti-apoptotic function, but their clinical utility can be limited by dose-limiting thrombocytopenia due to Bcl-xL's role in platelet survival.

Other names

BCL2L1Bcl2-L-1Bcl-XBcl-xLBcl-xS

Inhibition of anti-apoptotic activity (by BH3-mimetic drugs) to induce apoptosis in malignant cells