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Updated: Mar 9, 2026

Examining BCL-2 Family Function with Large Unilamellar Vesicles
Published on: October 5, 2012
Bax transmembrane domain interacts with prosurvival Bcl-2 proteins in biological membranes
Vicente Andreu-Fernández1,2,3, Mónica Sancho1, Ainhoa Genovés1
1Laboratory of Peptide and Protein Chemistry, Centro de Investigación Príncipe Felipe, E-46012 Valencia, Spain.
Abstract:
The Bcl-2 (B-cell lymphoma 2) protein Bax (Bcl-2 associated X, apoptosis regulator) can commit cells to apoptosis via outer mitochondrial membrane permeabilization. Bax activity is controlled in healthy cells by prosurvival Bcl-2 proteins. C-terminal Bax transmembrane domain interactions were implicated recently in Bax pore formation. Here, we show that the isolated transmembrane domains of Bax, Bcl-xL (B-cell lymphoma-extra large), and Bcl-2 can mediate interactions between Bax and prosurvival proteins inside the membrane in the absence of apoptotic stimuli. Bcl-2 protein transmembrane domains specifically homooligomerize and heterooligomerize in bacterial and mitochondrial membranes. Their interactions participate in the regulation of Bcl-2 proteins, thus modulating apoptotic activity. Our results suggest that interactions between the transmembrane domains of Bax and antiapoptotic Bcl-2 proteins represent a previously unappreciated level of apoptosis regulation.
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