The fact that MAVS is located within the membrane of the mitochondrion makes sense for a couple of reasons, Dr. Chen said.

First, proteins housed within the mitochondria have been shown by researchers, such as UT Southwestern biochemist Dr. Xiaodong Wang and others, to play a role in apoptosis, or programmed cell death. The fact that MAVS is located in the membrane of mitochondria suggests it may play a role in coordinating cell death and immune response, Dr. Chen said.

Secondly, many scientists believe that mitochondria originally evolved from bacteria that lived within a host organism's cells, eventually developing a symbiotic relationship with host cells. Now that mitochondria are an integral part of our cells, Dr. Chen speculated that mitochondria may have acquired new functions by serving as a sentinel to detect invading pathogens and other stressful signals, ensuring that the host cells survive and thrive even in adverse environments.

Dr. Chen and his research group are currently working to determine how the MAVS protein functions within the complex series of biochemical reactions that takes place when the body is infected with a virus.

Researchers at UT Southwestern, led by microbiologist Dr. Michael Gale, and elsewhere have previously found that when an RNA virus invades a cell, a protein called RIG-I first intercepts the virus and binds to viral genetic material. That interaction starts a cascade of biochemical reactions that eventually triggers the cell to make a protein called interferon, which in turn fights off the virus.

But the chain of events between RIG-I's encounter with the virus and the interferon response is not known.
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Contact: Amanda Siegfried
amanda.siegfried@utsouthwestern.edu
214-648-3404
UT Southwestern Medical Center
25-Aug-2005