My lab is interested in mitochondrial carrier structure and function, especially the
ADP/ATP carrier of yeast. In collaboration with Dr. Martin Klingenberg of Munich
Germany, I am making site directed mutants of amino acids I believe will inactivate the
protein. These mutants are glycerol minus (unable to grow by respiration on glycerol/
ethanol as a carbon source.) Once mutants are characterized as glycerol minus, Dr.
Klingenberg’s lab purifies the mutant protein from yeast mitochondria and characterizes
it biochemically in a reconstituted transport assay system. We then try to select for
regain of function mutations in the same gene (AAC2) that restore the glycerol growth
phenotype. These mutant plasmids are then recovered from the yeast and sequenced to
find the second mutation. We are currently building up sets of mutants that inactivate
and then restore activity. These often involve charge pairs. When one charge is lost
the function is lost but it is regained when a complementary charge is also lost, thus a
charge pair is predicted.
In collaboration with Dr. Ron Kaplan of the University of South Alabama in
Mobile, a deletion of the citrate carrier gene from yeast has been made.
In that background, the yeast gene, or the rat liver gene for the citrate
carrier can be expressed and mutated.