Task Progress:
|
Astronauts are exposed to harmful conditions in space, particularly radiation from the sun and cosmic rays and partial gravity. Ionizing radiation removes electrons from water molecules, resulting in oxidizing conditions harmful to protein, fat, and DNA integrity. Depending on the astronaut’s genetic makeup, they can be more or less sensitive to these harmful conditions. For example, Parkinson's disease risk can increase due to exposure to agents that are known to cause oxidizing conditions in human cells, as well as to genetic changes in a particular protein, synuclein. Therefore, we are interested in exploring a relationship between synuclein and the oxidizing effects of radiation.
Budding yeast (brewer’s or baker’s yeast) is often used as a model to study basic mechanisms that also operate in human cells, because many basic cell processes are the same, but genetic modification and analysis are straightforward and rapid. We are preparing to test whether specific alterations to the yeast genetic makeup make them more or less sensitive to radiation-induced oxidizing conditions. The Parkinson's-related protein, synuclein, is normally present in human cells, but not yeast cells. We have used recombinant DNA methods to alter the yeast to synthesize this protein under conditions we impose. During this year of the project, we constructed a set of genetically modified yeast that will allow us to ask two questions:
-Does the presence of synuclein increase sensitivity to (death from) radiation?
-Do increased levels of a conserved antioxidant protein protect cells (with or without synuclein protein) from radiation effects?
We had, in the previous year, made a set of strains for this purpose, but found that these yeast strains were unable to survive the drying process needed to eventually be tested in lunar or space conditions. Therefore, we identified a better genetic makeup for this purpose and recreated our set of strains using this genetic makeup. Our testing is upcoming for visualizing yeast synthesis of synuclein, as well as testing the effects on radiation survival of making this protein.
|