This chapter contains sections titled: Introduction AR JP and Parkin ARJP: Introduction PARKIN: The Gene PARKIN: Localization and Regulation Parkin in the Ubiquitin–Proteasome Pathway The Ubiquitin–Proteasome Pathway PARKIN: An E3 Ubiquitin Ligase Parkin and Lewy Bodies Parkin Substrates Parkin in Neuroprotection Toxic Parkin Substrates Stress-mediated Toxicity Parkin and Other PD-linked Genes α-Synuclein DJ-1 LRRK2 Mechanisms of Parkin Dysfunction Pathogenic Mutations Cellular Regulators of Parkin Post-translational Regulation of Parkin Animal Models of Parkin Deficiency Drosophila Models Mouse Models Concluding Remarks References