Receptor-specific interactome as a hub for rapid cue-induced selective translation in axons

During neuronal wiring, extrinsic cues trigger the local translation of specific mRNAs in axons via cell surface receptors. The coupling of ribosomes to receptors has been proposed as a mechanism linking signals to local translation but it is not known how broadly this mechanism operates, nor whether it can selectively regulate mRNA translation. We report that receptor-ribosome coupling is employed by multiple guidance cue receptors and this interaction is mRNA-dependent. We find that different receptors bind to distinct sets of mRNAs and RNA-binding proteins. Cue stimulation induces rapid dissociation of ribosomes from receptors and the selective translation of receptor-specific mRNAs in retinal axon growth cones. Further, we show that receptor-ribosome dissociation and cue-induced selective translation are inhibited by simultaneous exposure to translation-repressive cues, suggesting a novel mode of signal integration. Our findings reveal receptor-specific interactomes and provide a general model for the rapid, localized and selective control of cue-induced translation.