Methionine Sulfoxide Reductase Msr Deficiency Leads to a Reduction in Dopamine Levels in Drosophila

Biological homeostasis relies on protective mechanisms that respond to cellular oxidation
caused primarily by free radical reactions. Methionine sulfoxide reductases Msr are a class of
enzymes that reverse oxidative damage to methionine. The focus of this study is on the
relationship between Msr and dopamine in Drosophila. Dopaminergic neurons in drosophila
have comparable roles to those found in humans. A deficit in dopamine leads to the onset of
many neurological disorders including the loss of fine motor control—a neurodegenerative
condition characteristic of Parkinson’s disease PD. We have found that dopamine levels in the
heads of MsrAΔ/ΔBΔ/Δ mutants are significantly reduced in comparison
to the wild type. In addition, we have found that TH protein and expression levels are markedly
reduced in an Msr-deficient system. Our findings suggest that it is possible the Msr system plays
an important role in maintaining dopaminergic neurons alive, and thus, is protectant of the CNS.