Associates with the adapter-like complex 4 (AP-4 and may therefore play a role in vesicular trafficking of proteins at the trans-Golgi network. Signaling adapter which plays a role in neuronal differentiation. Involved in regulation of NGF-dependent neurite outgrowth. May play a role in neuronal vesicular trafficking, specifically involving pre-synaptic membrane proteins (By similarity. Seems to be involved in signaling pathways that are regulated by the prolonged activation of MAPK. Can regulate the polyubiquitination of IKBKG and thus may be involved in regulation of the NF-kappa-B pathway.