MAPT and Alzheimer disease: Particularly, hyperphosphorylation of Tau promotes neuronal degeneration, and the fibrillar deposits of highly phosphorylated Tau is a defining marker of neurodegeneration including.203 Studies in PD and AD models showed co-localization of α-Syn with phospho-GSK-3β and phospho-Tau, and indicated that α-Syn may act as a scaffolding molecule that is necessary for the activation of GSK-3β and the subsequent Tau hyperphosphorylation.204,205 Taken together, these studies indicate that LRRK2 may be critically involved in the Tau pathology in PD.