Uncoupling of calcium channel alpha1 and beta subunits in developing neurons.
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.
Spafford
J David
JD
Cellular and Molecular Neurobiology Research Group, University of Calgary, Calgary T2N 4N1, Canada.
Van Minnen
Jan
J
Larsen
Peter
P
Smit
August B
AB
Syed
Naweed I
NI
Zamponi
Gerald W
GW
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
D020864:Calcium Channels, N-Type; D018076:DNA, Complementary; D018377:Neurotransmitter Agents; D016376:Oligonucleotides, Antisense; D020033:Protein Isoforms; D012313:RNA