The membrane insertion of the pro-apoptotic protein Bax is a Tom22-dependent multi-step process: a study in nanodiscs (Updated April 19, 2024).

A preprint abstract from biorxiv.org discusses the membrane insertion of the pro-apoptotic protein Bax. The study found that Bax was not spontaneously inserted in nanodiscs, but co-synthesis with the mitochondrial receptor Tom22 promoted Bax membrane insertion. The interaction of Bax with the lipid bilayer exposed a specific motif, which was recognized by Tom22 and triggered conformational changes leading to membrane insertion. The study also found that the effect of Tom22 was impaired by certain substitutions found in tumors, while another substitution promoted the spontaneous insertion of Bax in nanodiscs. The regulation of Bax membrane insertion by Tom22 and BH3-activators is discussed. [Extracted from the article]