The Parkinson's disease-associated DJ-1 protein is a transcriptional co-activator that protects against neuronal apoptosis.

Mutations in the DJ-1 gene cause early-onset autosomal recessive Parkinson's disease (PD), although the role of DJ-1 in the degeneration of dopaminergic neurons is unresolved. Here we show that the major interacting-proteins with DJ-1 in dopaminergic neuronal cells are the nuclear proteins p54nrb and pyrimidine tract-binding protein-associated splicing factor (PSF), two multifunctional regulators of transcription and RNA metabolism. PD-associated DJ-1 mutants exhibit decreased nuclear distribution and increased mitochondrial localization, resulting in diminished co-localization with co-activator p54nrb and repressor PSF.

Dopamine inhibits cell growth and cell cycle by blocking ribonucleotide reductase.

Dopamine (DA) is a classical neurotransmitter modulating various brain functions by acting on its specific receptors. In addition, DA is a reactive molecule that has been implicated in neurodegeneration, especially in Parkinson's disease. Here we show that DA inhibited cell growth of dopamine transporter transfected cells by intracellularly blocking cell cycle progression.