Parkin Co-regulated Gene (PACRG) is regulated by the ubiquitin–proteasomal system and is present in the pathological features of parkinsonian diseases

Mutations in parkin are a common cause of early-onset autosomal recessive Parkinson's disease. Parkin Co-Regulated Gene (PACRG) is a novel gene that was discovered because of its close genetic proximity to parkin and the two genes were subsequently demonstrated to be regulated by a bi-directional promoter. However the role of PACRG has not been well characterized and the distribution of the protein in both normal and diseased brain is not known. Here, we report that like parkin, PACRG is regulated by the ubiquitin–proteasomal system. Immunohistochemistry identified PACRG in astrocytes throughout the brain and in pigmented noradrenergic neurons of the locus coeruleus. PACRG was also detected in Lewy bodies and glial cytoplasmic inclusions in patients with Parkinson's disease and Multiple System Atrophy, respectively. Together, these results demonstrate that PACRG is regulated by the ubiquitin–proteasomal system and may play a role in the pathogenesis of Parkinson's disease.