title: Semaphorin3A facilitates axonal transport through a local calcium signaling and tetrodotoxin-sensitive voltage-gated sodium channels.
abstract: Semaphorin3A (Sema3A), a secreted factor that navigates axons and dendrites of developing neurons, facilitates axonal transport. However, little is known about the mechanism underlying Sema3A-induced facilitation and its functional implications. Here we show that Sema3A induces facilitation of axonal transport via local calcium signaling in growth cone. The facilitation of axonal transport was blocked by inhibitors of voltage-gated sodium channels (tetrodotoxin, TTX), L-type voltage-gated calcium channel, and ryanodine receptor (RyR). Sema3A evoked intracellular Ca(2+) elevation in growth cone by local application of Sema3A to growth cone. Sema3A also activated RyR in growth cone as well as cell body. Notably, TTX suppressed Sema3A-induced RyR activation in cell body but not in growth cone. Our results identify a novel mechanism of Sema3A-induced axonal transport, and further suggest that Sema3A-induced local calcium signaling in growth cone is propagated to cell body in a TTX-sensitive manner.
authors.affiliation: Department of Molecular Pharmacology and Neurobiology, Yokohama City University, Graduate School of Medicine, Yokohama 236-0004, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamane
authors.forename: Naoya
authors.initials: N
authors.lastname: Yamashita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Akira
authors.initials: A
authors.lastname: Iizuka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shouji
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Usui
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Goshima
mesh_terms: D000818:Animals; D001369:Axons / Q000187:drug effects / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000378:metabolism; D020013:Calcium Signaling; D002460:Cell Line; D002642:Chick Embryo; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism; D020439:Growth Cones / Q000187:drug effects / Q000378:metabolism; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology*; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D040121:Semaphorin-3A / Q000378:metabolism*; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D019837:Ryanodine Receptor Calcium Release Channel; D040121:Semaphorin-3A; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D013779:Tetrodotoxin