Bak and Bax Proteins Active in Cell Death

U.S. researchers are discovering the operating mechanisms behind Bak and Bax — cell protein structures suspected in programmed cell death, or apoptosis.

These two proteins are very important for mitochondrial injury and subsequent apoptosis, corresponding author Zheng Dong, cell biologist at the Medical College of Georgia in Augusta, said in a statement.

We found out Bak has a distinct function in regulation of the mitochondrial morphology — Bax, on the other hand, is not involved in morphological regulation but needs to be there to puncture holes.

One has to break up, kind of soften, the mitochondria for injury, and the other one actually punches the holes to kill it,” according to first author Craig Brooks, a graduate student.

Dong suspects Bak may also play a role in mitofusin regulation in normal, non-stressful conditions.

“Some of the same proteins are needed for daily mitochondrial function like making energy, but if they are released from the mitochondria, they activate a cell killing or apoptotic pathway, according to the study published in the Proceedings of the National Academy of Sciences.

The researchers say better understanding of the cell suicide mechanism — apoptosis — is to develop drugs to block it in the case of a stroke, or induce it to kill cancer.