Role of Methionine Sulfoxide Reductase (MsrA) on Aging and Oxidative Stress in Drosophila

Oxidative damage is an inevitable consequence of aerobic respiration. Methionine
sulfoxide reductases (Msr) are a group of enzymes that function to repair oxidized
methionine residues in both free methionine and methionine in proteins. MsrA was the
first of these enzymes to be discovered and is the most thoroughly studied. It is thought to
play a role in both the aging process and probably several neurodegenerative diseases. I
recently obtained a strain of Drosophila that was reported to have a P-element transposon
located within Exon 2 (part of the open reading frame) of the eip71cd gene, which is the
Drosophila homolog of MsrA. Thus, the transposon insertion should disrupt expression
of the msrA gene. I did a series of experiments to "jump out" the P-element in an effort
to recover two types of isogenic strains. The first would be a null mutation of the MsrA
gene created by deletion of flanking genomic DNA when the P-element excised from the
chromosome. The second would be a precise excision of the P-element, which would
restore the genetic locus to its original structure. This study looks at the effect of a null
mutant of the MsrA gene on aging and resistance to oxidative stress.