Multiple glycoforms of TrkA interact with N-cadherin during trigeminal ganglion neurodevelopment.

The trigeminal ganglion is a sensory structure derived from neural crest and placode cells, leading to a heterogeneous neuronal population that transmits somatosensory information to the brain. Proper trigeminal ganglion development relies, in part, on neurotrophic signaling, including interactions between nerve growth factor and its receptor, tropomyosin receptor kinase A (TrkA). Although glycosylation is essential for the trafficking of TrkA to the plasma membrane, the glycan profile and functional relevance of these modifications in sensory neurons remains poorly defined in vivo. Here, we characterized TrkA glycosylation during chick trigeminal ganglion neurodevelopment and identified multiple glycoforms of TrkA corresponding to partially and fully mature protein states reported in vitro. Furthermore, we showed that TrkA interacts with the cell adhesion molecule N-cadherin on neuronal membranes both in cell bodies and axons. The molecular weights of interacting TrkA forms suggest that these associations occur at the plasma membrane as well as on intracellular organelle membranes. Our findings are the first to identify a biochemical association between TrkA and N-cadherin in the trigeminal ganglion, suggesting potential coordination between neurotrophic signaling and cell adhesion during development.