BCL-xL (BCL2L1)

BCL-xL is an anti-apoptotic member of the BCL-2 family that restrains mitochondrial outer-membrane permeabilization by binding pro-apoptotic family members.

Function

BCL-xL is embedded in the mitochondrial outer membrane, where it binds the pore-formers BAX and BAK and the BH3-only activators that activate them. Its binding groove is also the target of the BH3-only “sensitizer” proteins, so the amount of free BAX and BAK depends on the balance of these family members. The BCL2L1 gene is spliced into two main products: BCL-xL, the long anti-apoptotic form, and BCL-xS, a shorter pro-apoptotic form.

In cancer

BCL-xL is overexpressed in many carcinomas and in platelets, where it keeps anucleate cells