Biophysical Society Thematic Meeting - October 13-15, 2015

Biophysics of Proteins at Surfaces: Assembly, Activation, Signaling

Poster Abstracts

11-POS

Board 11

Investigating the Membrane Topology of Proapoptotic BAX Hector Flores Romero , Juan Garcia-Valero, Olatz Landeta, Ane Landajuela, Itsasne Bustillo- Zabalbeitia, Miguel Garcia-Porras, Oihana Terrones, Gorka Basañez. Biophysics Unit CSIC-UPV/EHU, Barrio Sarriena, Leioa 48940, Spain. Mitochondrial outer membrane (MOM) permeabilization is the point of no return in many forms of apoptotic cell death. The BCL2 family member BAX is a crucial effector of MOM permeabilization that adopts an inactive conformation in the cytosol of healthy cells. It is well established that functional BAX activation is a complicated process, initiated by translocation of BAX to the MOM and culminating with assembly of BAX into a protein-permeable apoptotic pore. However, most of our current structural knowledge of BAX originates from studies in membrane-free environments. Given the inherent complexity of the cellular apoptotic network, here we used the single-cysteine accessibility methodology applied to in vitro reconstituted systems (MOM-like liposomes and isolated mitochondria) to gain structural and mechanistic information about BAX in a membrane environment.

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