ABSTRACT
The study of the cell biology of amyloid precursor protein is driven by the question how its abnormal biochemical processing can cause neurodegeneration. Most investigations have therefore focussed on its metabolism in general and the generation of the amyloid peptide in particular. Other aspects of its cell biology, including its function, have still to be studied in more detail. One clue to the function of amyloid precursor protein is hidden in its fundamental property to traffic throughout the different subcellular compartments of the secretory and the endocytic pathways. This has also implications for its metabolic processing, which can therefore only be understood in the context of (polarized) protein transport in the cell. This will become the main topic of the current chapter. For a more detailed discussion of the function of amyloid precursor protein and of the characteristics of the enzymes (“secretases”) involved in its processing, the reader is referred to the contributions in this volume by Masters, Multhaup and Beyreuther and by Citron and Selkoe.
