Calbindin-D28K acts as a calcium-dependent chaperone suppressing α-synuclein fibrillation in vitro

Abstract

α-Synuclein, a natively unfolded protein aggregation which is implicated in the pathogenesis of Parkinson's disease and several other neurodegenerative diseases, is known to interact with a great number of unrelated proteins. Some of these proteins, such as ß-synuclein and DJ-1, were shown to inhibit α-synuclein aggregation in vitro and in vivo therefore acting as chaperones. Since calbindin-D 28K is co-localized with Ca 2+ neuronal membrane pumps, and since α-synuclein is also found in the membrane proximity, these two proteins can potentially interact in vivo. Here we show that calbindin-D28K interacts with α-synuclein and inhibits its fibrillation in a calciumdependent manner, therefore potentially acting as a calcium-dependent chaperone.