Investigation of the Bcl-2 multimerisation process: Structural and functional implications.

Bcl-2 plays a prominent role in regulating the function of mitochondria during respiration and in determining the threshold of apoptotic sensitivity. Despite its relevance, the mechanism through which these processes are achieved is still unknown. Using surface plasmon resonance technology to monitor Bcl-2 multimerisation we discovered that a simple dimeric model does not fit with experimental data. A molecular model of the experimentally observed Bcl-2 homomeric complex has been developed. Accordingly, using a panel of mutants we identified in the loop a critical region for the process of Bcl-2 multimerisation. Our results indicate that the Bcl-2 loop posttranscriptional changes can modulate its ability to make homo and hetero-complexes, ultimately leading to functional modulation, suggesting an intriguing relationship between the ability of Bcl-2 to form multimeric complexes and its multi-functional role as a membrane channel