title: Transsynaptic channelosomes: non-conducting roles of ion channels in synapse formation.
abstract: Recent findings demonstrate that synaptic channels are directly involved in the formation and maintenance of synapses by interacting with synapse organizers. The synaptic channels on the pre- and postsynaptic membranes possess non-conducting roles in addition to their functional roles as ion-conducting channels required for synaptic transmission. For example, presynaptic voltage-dependent calcium channels link the target-derived synapse organizer laminin β2 to cytomatrix of the active zone and function as scaffolding proteins to organize the presynaptic active zones. Furthermore, postsynaptic δ2-type glutamate receptors organize the synapses by forming transsynaptic protein complexes with presynaptic neurexins through synapse organizer cerebellin 1 precursor proteins. Interestingly, the synaptic clustering of AMPA receptors is regulated by neuronal activity-regulated pentraxins, while postsynaptic differentiation is induced by the interaction of postsynaptic calcium channels and thrombospondins. This review will focus on the non-conducting functions of ion-channels that contribute to the synapse formation in concert with synapse organizers and active-zone-specific proteins.
authors.affiliation: Department of Anatomy and Cell Biology, Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical School, Kansas City, KS, USA. hnishimune@kumc.edu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishimune
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D006801:Humans; D007797:Laminin / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism; D018091:Receptors, AMPA / Q000378:metabolism; D013570:Synaptic Membranes / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology*; D019699:Thrombospondins / Q000378:metabolism
chemical_list: C484271:CBLN1 protein, human; D015220:Calcium Channels; D007797:Laminin; D009419:Nerve Tissue Proteins; D011498:Protein Precursors; D018091:Receptors, AMPA; D019699:Thrombospondins; C058783:laminin beta2