Scientiae forum / Models and speculations Pathways for axonal targeting of membrane proteins

The distribution of proteins to the correct domains of neurons is crucial for neuronal functioning. Here I discuss possible mechanisms underlying sorting to the axonal plasma membrane which differ with respect to the steps providing selectivity for axonal vs. somatodendritic cargo. Selectivity can be executed at one or more than one step, including sorting into distinct carriers in the Golgi, preferential transport along axonal microtubules, fusion with the plasma membrane, and importantly retrieval by endocytosis. A protein might in fact be sorted multiple times at different places to achieve axonal localization.