Alpha-synuclein is part of a diverse and highly conserved interaction network that includes PARK9 and manganese toxicity.

Susan Lindquist and colleagues report a genetic interaction between α-synuclein and the ortholog of human ATP13A2 (PARK9) in yeast, two genes that when mutated cause Parkinson's disease. They further show that yeast PARK9 protects cells from manganese toxicity, a known environmental risk factor for Parkinson's disease.