Description
Functions as a cell surface receptor and performs physiological functions on the surface ofneurons relevant to neurite growth, neuronal adhesion and axonogenesis (1). Involved incell mobility and transcription regulation through protein-protein interactions. Canpromote transcription activation through binding to APBB1-KAT5 and inhibits Notch signalling through interaction with Numb. Couples to apoptosis-inducing pathways such asthose mediated by G(O) and JIP (2). Inhibits G(O) alpha ATPase activity. Acts as a kinesin Imembrane receptor, mediating the axonal transport of beta-secretase and presenilin 1. Involved in copper homeostasis/oxidative stress through copper ion reduction. In vitro, copper-metallated APP induces neuronal death directly or is potentiated through Cu2+-mediated low-density lipoprotein oxidation (3). Can regulate neurite out growth through binding to components of the extracellular matrix such as heparin and collagen I and IV. APP is involved in Alzheimer disease which is caused by mutations affecting the gene codingfor the protein (4). Alzheimer disease is a neurodegenerative disorder characterized byprogressive dementia, loss of cognitive abilities, and deposition of fibrillar amyloid proteinsas intraneuronal neurofibrillary tangles, extracellular amyloid plaques and vascularamyloid deposits. The major constituents of these plaques are neurotoxic amyloid-betaprotein 40 and amyloid-beta protein 42, that are produced by the proteolysis of thetransmembrane APP protein (5)