Signals involved in targeting membrane proteins to synaptic vesicles.

1. Synaptic vesicles (SVs) mediate fast regulated secretion of classical neurotransmitters. In order to perform their task SVs rely on a restrict set of membrane proteins. The mechanisms responsible for targeting these proteins to the SV membrane are still poorly understood. 2. Likewise, little is known about the intracellular routes taken by these proteins in their way to SV membrane. Recently, several domains and motifs necessary for correct localization of SV proteins have been identified. 3. In this review we summarize the sequence motifs that have been identified in the cytoplasmic domains of SV proteins that are involved in endocytosis and targeting of SVs. We suggest that the vesicular acetylcholine transporter, a protein found predominantly in synaptic vesicles, is perhaps a model protein to understand the pathways and interactions that are used for synaptic vesicle targeting.