The functions and signaling pathways induced by the interactions of APP–related molecules with p75

p75 neurotrophin receptor (p75) regulates diverse functions, including survival, differentiation, growth, and apoptosis of neurons, through its association with a number of molecules. Accumulating evidence shows that βamyloid precursor protein (APP)–related molecules, which also regulate multiple neuronal functions, interact with p75. APP is cleaved by secretases to generate several proteins including soluble β-amyloid precursor protein alpha (sAPPα), sAPPβ, and amyloid β (Aβ). Binding of Aβ to p75 induces neuronal death. In contrast, sAPPα directly interacts with p75 to enhance neurite outgrowth through the activation of protein kinase A (PKA). This review focuses on the molecular mechanisms and functions occurring as a consequence of interactions of p75 with APP–related molecules.