title: Uncoupling of calcium channel alpha1 and beta subunits in developing neurons.
abstract: Calcium channel beta subunits are key modulators of calcium channel function and membrane targeting of the pore-forming alpha1 subunit. Here we show that an invertebrate (Lymnaea stagnalis) homolog of P/Q- and N-type calcium channels (LCav2), although colocalized with beta subunits in synapses of mature neurons, is physically uncoupled from the beta subunits in the leading edge of growth cones of outgrowing neurons. Moreover, LCav2 channels that mediate transmitter release in mature synapses also participate in neuronal outgrowth in growth cones. The differential association of beta subunits with synaptic calcium channels and those expressed in emergent neuronal growth suggests that beta subunits may play a role in the transformation of Cav2 calcium channel function in immature neurons and mature synapses.
authors.affiliation: Cellular and Molecular Neurobiology Research Group, University of Calgary, Calgary T2N 4N1, Canada.
authors.forename: J David
authors.initials: JD
authors.lastname: Spafford
authors.forename: Jan
authors.initials: J
authors.lastname: Van Minnen
authors.forename: Peter
authors.initials: P
authors.lastname: Larsen
authors.forename: August B
authors.initials: AB
authors.lastname: Smit
authors.forename: Naweed I
authors.initials: NI
authors.lastname: Syed
authors.forename: Gerald W
authors.initials: GW
authors.lastname: Zamponi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000196:embryology / Q000378:metabolism; D020864:Calcium Channels, N-Type / Q000737:chemistry*; D002478:Cells, Cultured; D002490:Central Nervous System / Q000196:embryology*; D002645:Chickens; D018076:DNA, Complementary / Q000378:metabolism; D004594:Electrophysiology; D017403:In Situ Hybridization; D008195:Lymnaea; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000737:chemistry; D018408:Patch-Clamp Techniques; D010802:Phylogeny; D020033:Protein Isoforms; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013569:Synapses; D013997:Time Factors; D014162:Transfection
chemical_list: D020864:Calcium Channels, N-Type; D018076:DNA, Complementary; D018377:Neurotransmitter Agents; D016376:Oligonucleotides, Antisense; D020033:Protein Isoforms; D012313:RNA