RESUMO
It has been proposed that cell-type-specific bioelectronic interfaces for neuronal circuits could be established by utilizing the function of synapse organizers. For this purpose, using neurexin-1ß and a peptide tag, we engineered compact synapse organizers that do not interact with the naturally occurring receptors but induce presynaptic differentiation upon contact with nanobody-decorated objects in cultured mammalian and chick forebrain neurons. In chick neurons, the engineered organizer exerted synaptogenesis typically in â¼4 h after the contact, even under an air atmosphere at room temperature, thereby providing a useful cellular model for establishing the molecularly inducible neuron-microelectrode interface.
Assuntos
Neurônios , Sinapses , Animais , Microeletrodos , Sinapses/fisiologia , Diferenciação Celular , Peptídeos , MamíferosRESUMO
Clustering of neurexin-1ß occurs through the formation of a trans-cellular complex with neuroligin-1, which promotes the generation of presynapse. While the extracellular region of neurexin-1ß functions to constitute the heterophilic binding interface with neuroligin-1, it has remained unclear whether the region could also play any key role in exerting the intracellular signaling for presynaptic differentiation. In this study, we generated neurexin-1ß lacking the binding site to neuroligin-1 and with a FLAG epitope at the N-terminus, and examined its activity in cultured neurons. The engineered protein still exhibited robust synaptogenic activities upon the epitope-mediated clustering, indicating that the region for complex formation and that for transmitting presynapse differentiation signals are structurally independent of each other. Using a fluorescence protein as an epitope, synaptogenesis was also induced by a gene-codable nanobody. The finding opens possibilities of neurexin-1ß as a platform for developing various molecular tools which may allow, for example, precise modifications of neural wirings under genetic control.