Cell
Volume 80, Issue 2, 27 January 1995, Pages 285-291
Journal home page for Cell

Article
Bad, a heterodimeric partner for Bcl-xL and Bcl-2, displaces bax and promotes cell death

https://doi.org/10.1016/0092-8674(95)90411-5Get rights and content
Under an Elsevier user license
open archive

Abstract

To extend the mammalian cell death pathway, we screened for further Bcl-2 interacting proteins. Both yeast two-hybrid screening and λ expression cloning identified a novel interacting protein, Bad, whose homology to Bcl-2 is limited to the BH1 and BH2 domains. Bad selectively dimerized with BCl-xL as well as Bcl-2, but not with Bax, Bcl-xS, Mcl-1, A1, or itself. Bad binds more strongly to Bcl-xL than Bcl-2 in mammalian cells, and it reversed the death repressor activity of Bcl-xL, but not that of Bcl-2. When Bad dimerized with Bcl-xL, Bax was displaced and apoptosis was restored. When approximately half of Bax was heterodimerized, death was inhibited. The susceptibility of a cell to a death signal is determined by these competing dimerizations in which levels of Bad influence the effectiveness of Bcl-2 versus BCI-xL in repressing death.

Cited by (0)