Axonal transport and the delivery of pre-synaptic components

The mechanisms for delivering components to nerve terminals are diverse and highly regulated. The diversity of kinesin motors alone is insufficient to account for the specificity of delivery. Additional specificity and control are contributed by adaptor proteins and associated regulatory molecules. The interaction of cargos with these complexes can confer distinct behaviors on the transport of synaptic organelles. The rich regulatory mechanisms of transport that are only now emerging as the cargo–motor complexes are defined and subsequent local events that regulate their dynamic relationship are examined. Here we review recent studies of kinesin-related axonal transport of three crucial synaptic components, Piccolo-bassoon Transport Vesicles (PTVs), Synaptic Vesicle Precursors (SVPs), and mitochondria, and the mechanisms that modulate their transport.