Parkinson's disease (PD) is an important neurological disorder that afflicts over one million North Americans and is characterized by gait difficulty, rigidity, and tremor. Although Symptoms & Side Effects therapies are effective in the early stages of PD, no treatments exist to alter the inexorable progression of the disorder. The recent identification of several genes that underlie familial forms of PD has afforded new clues regarding the molecular pathogenesis of PD. We have focused on Parkin, a PD gene that is defective in a large percentage of familial, early-onset PD patients. Our goals are to understand how defects in this gene lead to PD, and furthermore to attempt to apply this knowledge directly to novel PD therapies. There is evidence that Parkin may normally play a role in the degradation of cellular proteins, and it has therefore been hypothesized that defects in Parkin may cause PD as a consequence of the accumulation of unwanted and toxic proteins. We will study the cellular mechanisms of Parkin activity, and investigate potential treatments of Parkin deficiency. Of note, we hypothesize that such treatments may be beneficial in sporadic forms of PD.