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The membrane activity of BOK involves formation of large, stable toroidal pores and is promoted by cBID
Author(s) -
FernándezMarrero Yuniel,
Bleicken Stephanie,
Das Kushal Kumar,
Bachmann Daniel,
Kaufmann Thomas,
GarciaSaez Ana J.
Publication year - 2017
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.14008
Subject(s) - toroid , biophysics , chemistry , membrane , microbiology and biotechnology , physics , biology , plasma , biochemistry , quantum mechanics
The BCL ‐2 family members are key regulators of the intrinsic apoptotic pathway, which is defined by permeabilization of the mitochondrial outer membrane by members of the BAX ‐like subfamily. BOK is classified as a BAX ‐like protein; however, its (patho‐)physiological role remains largely unclear. We therefore assessed the membrane permeabilization potential of C‐terminally truncated recombinant BOK , BOK ∆C . We show that BOK ∆C can permeabilize liposomes mimicking the composition of mitochondrial outer membrane, but not of endoplasmic reticulum, forming large and stable pores over time. Importantly, pore formation was enhanced by the presence of cBID and refractory to the addition of antiapoptotic BCL ‐ X L . However, isolated mitochondria from Bax −/− Bak −/− cells were resistant to BOK ‐induced cytochrome c release, even in the presence of cBID . Taken together, we show that BOK ∆C can permeabilize liposomes, and cooperate with cBID , but its role in directly mediating mitochondrial permeabilization is unclear and may underlie a yet to be determined negative regulation.