Research teams from the Walter
and Eliza Hall Institute combined to discover both the three-dimensional structure
of a key cell death protein, Bak, as well as an understanding of the first
steps in how Bak causes cell death. Apoptosis, programmed cell death, occurs when
chemical signals activate Bak and Bax. The activation of Bak and Bax tells the
cell to die by targeting the mitochondria. When apoptosis is working
effectively unwanted cells are killed and removed from the body. However, when
trouble with apoptosis occurs harmful cells, such as cancer cells, continue to
grow or healthy cells die unnecessarily, such as what happens in Alzheimer's
disease.
Specifically, the team’s research
showed how Bak changes from one form to another form in order to initiate apoptosis.
Additionally, the research team discovered how the Bak and Bax protein dimers
attach to the mitochondria and perforate the mitochondria. It has been understood
that the Bak and Bax dimers open the mitochondrial surface; however, the
mechanism for how the dimers perforate the mitochondria was previously poorly
understood.
Scientists originally believed that
Bak and Bax poked a hole through the surface of the mitochondria; however, the
team’s research disproved this belief. Instead the team discovered that the
dimers attach onto the oily surface of the mitochondria and crowd the surface
until holes form in the surface. What still remains unknown is exactly how the
proteins come together to destroy the mitochondria and initiate apoptosis.
I found this article very
interesting because this small development will lead to a much greater understanding
of apoptosis in the future. Now that researchers are able to understand the structures
of the proteins involved apoptosis they have the necessary information to begin
advancing towards a deeper understanding of apoptosis, specifically the initiation
of the process. This research will be crucial to understanding how to regulate
apoptosis to combat diseases such as lupus, cancers and neurodegenerative diseases.
Secondary Article: http://www.cell.com/molecular-cell/abstract/S1097-2765(14)00609-1
Secondary Article: http://www.pnas.org/content/111/39/E4076.full
I really like this article. A good friend of mine has lupus and has major problems with her platelet counts. Now I understand why this happens to her, because apoptosis is not working normally and her healthy cells are dying unnecessarily. This discovery is a huge step in finding cures to diseases such as lupus. Great post.
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