Analysis of synphilin-1 and synuclein interactions by yeast two-hybrid beta-galactosidase liquid assay

Synphilin-1 interacts with alpha-synuclein, which has been implicated in the pathogenesis of Parkinson's disease (PD). By examination of their interactions quantitatively, with the use of the yeast two-hybrid beta-galactosidase assay, we find that the synuclein amino acid (aa) 1-65 region is sufficient for an interaction. A central domain of synphilin-1, aa 349-555, is both necessary and sufficient for an interaction with alpha-synuclein. We did not observe an effect of the synuclein A53T mutation, which causes one familial form of PD, on interactions with synphilin-1. However, the A30P mutation caused an increase in the interaction between the synuclein aa 1-65 fragment and the synphilin-1 central domain.