Synapse and Active Zone Assembly in the Absence of Presynaptic Ca2+ Channels and Ca2+ Entry
Synapse and Active Zone Assembly in the Absence of Presynaptic Ca2+ Channels and Ca2+ Entry
复制标题
DOI：
10.1016/j.neuron.2020.05.032
复制
发表时间：
2020-08-19
期刊：
影响因子：
16.2
通讯作者：
Kaeser, Pascal S.
中科院分区：
文献类型：
--
作者：
Held, Richard G.;Liu, Changliang;Kaeser, Pascal S.
突触前Ca（v）2通道对Ca 2+触发的胞吐作用是必不可少的。此外，对于它们在突触结构中的作用，有两种相互竞争的模型。首先，Ca 2+通道或Ca 2+进入可以控制突触组装。第二，活动区蛋白可以将Ca（v）2s支架到突触前释放位点，并且突触结构是Ca（v）2独立的。在这里，我们消融所有三个Ca（v）2使用条件性敲除培养的海马神经元或在杯的Held，这废除了诱发胞吐。令人信服的是，突触和活动区结构，囊泡对接，和跨突触纳米组织没有受损。类似地，动作电位和Ca 2+进入的长期阻断并不破坏活动区组装。虽然Ca（v）2基因敲除削弱了β亚基的定位，但α 2 δ-1定位正常。用Ca（v）2的救援恢复胞吐作用，并且Ca（v）2活性区靶向依赖于细胞内C-末端。我们的结论是，突触组装是独立的Ca（v）2s或Ca 2+进入通过他们。相反，活性区蛋白通过Ca（v）2 C-末端募集和锚Ca（v）2 s。
Presynaptic Ca(v)2 channels are essential for Ca2+-triggered exocytosis. In addition, there are two competing models for their roles in synapse structure. First, Ca2+ channels or Ca2+ entry may control synapse assembly. Second, active zone proteins may scaffold Ca(v)2s to presynaptic release sites, and synapse structure is Ca(v)2 independent. Here, we ablated all three Ca(v)2s using conditional knockout in cultured hippocampal neurons or at the calyx of Held, which abolished evoked exocytosis. Compellingly, synapse and active zone structure, vesicle docking, and transsynaptic nano-organization were unimpaired. Similarly, long-term blockade of action potentials and Ca2+ entry did not disrupt active zone assembly. Although Ca(v)2 knockout impaired the localization of beta subunits, alpha 2 delta-1 localized normally. Rescue with Ca(v)2 restored exocytosis, and Ca(v)2 active zone targeting depended on the intracellular C-terminus. We conclude that synapse assembly is independent of Ca(v)2s or Ca2+ entry through them. Instead, active zone proteins recruit and anchor Ca(v)2s via Ca(v)2 C-termini.