Parkin is a cytosolic E3 ubiquitin ligase that is recruited to the mitochondria during cellular stress and has been suggested to be involved in a variety of biological processes such as mitophagy. The recruitment of Parkin (PARK2) to the mitochondria is dependent upon the kinase activity and the accumulation of PINK1 on damaged mitochondria. Mutations in either PINK1 or Parkin genes disrupt this protective pathway and lead to the accumulation of damaged mitochondria. From a clinical standpoint, mutations in the PARK2 gene have been associated with the progression and onset of autosomal recessive juvenile parkinsonism. Without the presence of a quality control system such as that of the PINK1/Parkin pathway, the accumulation of damaged mitochondria could lead to increased levels of oxidative stress, a decrease in ATP, and the progression towards cellular death. However, many of the details regarding the mechanism of Parkin-mediated ubiquitination and its involvement in mitophagy are not fully established. The intent of this thesis is to further explore the function of Parkin by utilizing the yeast-two hybrid system to identify novel Parkin interactors/substrates. A HeLa (cervical cell carcinoma) cDNA library was screened using Parkin124-465 as the "bait" protein. From this screening, six positive Parkin interactors were isolated and characterized. Using this approach it is possible to gain a better understanding of the function of Parkin in regulating cellular processes such as mitophagy.