Changes in the two-dimensional electrophoresis pattern of the Parkinson's disease related protein DJ-1 in human SH-SY5Y neuroblastoma cells after dopamine treatment

DJ-1 is a mitochondrial protein linked to Parkinson's disease. DJ-1 has been suggested to have several possible functions, although it has been mainly associated to oxidative stress defence. Changes in the two-dimensional electrophoresis pattern have been thoroughly described as a consequence of oxidative modification of the Cys106 residue. There is accumulating evidence supporting a specific role of DJ-1 in protecting dopaminergic neurons from dopamine itself. By exposing SH-SY5Y human neuroblastoma catecholaminergic cells to dopamine, we observed a specific increase in the most acidic forms in the DJ-1 two-dimensional electrophoresis pattern together with a significant decrease of the most basic spot. Unlike cells exposed to generic oxidative conditions, no additional shift was observed. The results are corroborated by a meta-analysis of the literature showing that in the absence of dopamine treatment the specific acidic form is underrepresented.