Parkin is associated with actin filaments in neuronal and nonneural cells

Inactivating mutations of the gene encoding parkin are responsible for auto somal recessive juvenile parkinsonism (AR-JP). However, little information is known about the function and distribution of parkin. We generated antibo dies to two different peptides of parkin. By Western blot analysis and immu nohistochemistry, we found that parkin is a 50-kd protein that is expressed in neuronal processes and cytoplasm of selected neurons in the basal gangl ia, midbrain, cerebellum, and cerebral cortex. Unlike ubiquitin and alpha - synuclein, parkin labeling was not found in Lewy bodies of four sporadic Pa rkinson disease brains. Parkin was colocaized with actin filaments but not with microtubules in COS1 kidney cells and nerve growth factor-induced PC12 neurons. These results point to the importance of the cytoskeleton and ass ociated proteins in neurodegeneration.