News Brief by Mohamad Hamze
Automated cell death is a key measure in preventing cancer, the destructive and uninhibited proliferation of cells. This regulatory mechanism has been studied at length at the site of the mitochondrial membrane, where the Bcl-2 family of proteins is responsible for perforation of the membrane and subsequent release of apoptotic proteins from the mitochondrial matrix. For the first time, researchers at Germany’s University of Tübingen have observed the actual structures formed by Bax proteins on the mitochondrial membrane surface.
These Bax proteins – part of the Bcl-2 family – mediate the final step of mitochondrial membrane perforation, which is seen as one of the terminal steps of cell suicide. The so-called “apoptotic pores” that result from Bax protein congregation appeared to biochemist Raquel Salvador-Galleogo as “rings, arcs, and lines” on the surface of the mitochondrial membrane. The creation of these pores irreversibly compromises the mitochondrial structure and releases cytochrome c, a signal for the continuation of apoptosis in the cell.
A comprehensive understanding of the mechanisms of cell-mediated apoptosis is invaluable in research on cancer-prevention and treatments. With a key segment of cell death now visualized, researchers have a number of new possible approaches to study the role apoptotic faults have in the proliferation of cancerous cells.
Plataforma SINC. "Doughnut-shaped holes of killer proteins observed for the first time." ScienceDaily. ScienceDaily, 18 February 2016. <www.sciencedaily.com/releases/2016/02/160218060935.htm>.