The Presynaptic Calcium Channel Is Part of a Transmembrane Complex Linking a Synaptic Laminin (α4β2γ1) with Non-Erythroid Spectrin
The Presynaptic Calcium Channel Is Part of a Transmembrane Complex Linking a Synaptic Laminin (α4β2γ1) with Non-Erythroid Spectrin
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突触前钙通道是连接突触层粘连蛋白 (α4β2γ1) 与非红系血影蛋白的跨膜复合体的一部分
作者:
W. J. Sunderland;Y. Son;J. Miner;J. Sanes;S. Carlson
Nerve regeneration studies at the neuromuscular junction (NMJ) suggest that synaptic basal lamina components tell the returning axon where to locate neurotransmitter release machinery, including synaptic vesicle clusters and active zones. Good candidates for these components are the synaptic laminins (LNs) containing α4, α5, or β2 chains. Results from a β2 laminin knockout mouse have suggested a linkage of this extracellular laminin to cytosolic synaptic vesicle clusters. Here we report such a transmembrane link at the electric organ synapse, which is homologous to the NMJ. We immunopurified electric organ synaptosomes and found on their surface two laminins of 740 and 900 kDa. The 740 kDa laminin has a composition of α4β2γ1 (laminin-9). Immunostaining reveals that as in the NMJ, α4 and β2 chains are concentrated at the electric organ synapse. Using detergent-solubilized synaptosomes, we immunoprecipitated a complex containing α4β2γ1 laminin, the voltage-gated calcium channel, and the cytoskeletal protein spectrin. Other presynaptic proteins such as 900 kDa laminin are not found in this complex. We hypothesize that α4β2γ1 laminin in the synaptic basal lamina attaches to calcium channel, which in turn is attached to cytosolic spectrin. Spectrin could then organize synaptic vesicle clusters by binding vesicle-associated proteins.
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DOI:
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发表时间:
1982
期刊:
Journal de physiologie
影响因子:
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作者:
Hooper,JE;Deutsch,JW;Miljanich,GP;Brasier,AR;Kelly,RB
通讯作者:
Kelly,RB
DOI:
--
发表时间:
1983
期刊:
The Journal of biological chemistry
影响因子:
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作者:
Froehner,SC;Douville,K;Klink,S;Culp,WJ
通讯作者:
Culp,WJ
DOI:
--
发表时间:
1981
期刊:
Journal of immunology (Baltimore, Md. : 1950)
影响因子:
--
作者:
Abo,T;Balch,CM
通讯作者:
Balch,CM
DOI:
10.1073/pnas.84.15.5464
发表时间:
1987
影响因子:
11.1
作者:
Umbach,JA;Gundersen,CB
通讯作者:
Gundersen,CB
DOI:
--
发表时间:
1986
期刊:
The Journal of biological chemistry
影响因子:
--
作者:
Chou,DK;Ilyas,AA;Evans,JE;Costello,C;Quarles,RH;Jungalwala,FB
通讯作者:
Jungalwala,FB