Aberrant proteolytic cleavage of the amyloid precursor protein (APP) leading to increased formation/accumulation of b-amyloid peptide (Aβ) is considered a central event in the pahogenesis of Alzheimer's disease (AD). Although much has been known about the Aβ generation and its clearance, we still do not understand in great detail how Aβ metabolism is altered in the most common late-onset form of AD (LOAD) and what are the molecular trigger(s) that initiate these events. In this project we will test the hypothesis that cholesterol metabolism and membrane trafficking are tightly linked and that their dysregulation leads to Alzheimer's disease.