Dendritic targeting and intracellular trafficking of neuroligin-1

Neuronal regulation and functionality is dependent on polarized protein distribution. Appropriate protein targeting is particularly relevant for proteins that contribute to synapse formation. Neuroligin-1 (NLG-1) mediates heterophilic synaptic adhesion with the axonal receptor β-neurexin and their interactions trigger the assembly of functional presynaptic terminals. A prerequisite for such a role in synapse formation is that NLG-1 should be exclusively targeted to the somato-dendritic domain and excluded from axons. Mutational analysis within the cytoplasmic domain in NLG-1 demonstrates that three equivalent signals target NLG-1 to the dendritic plasma membrane. Additionally, using a fluorescently-tagged NLG-1, NLG-1’s intracellular trafficking route was shown to contain the potassium channel Kv2.1 and Rab11b, and found to be in transferrin negative compartments. This work is significant because it will lead to a greater understanding of cellular and molecular mechanisms of nervous system development.