A Septin-Dependent Diffusion Barrier at Dendritic Spine Necks
A Septin-Dependent Diffusion Barrier at Dendritic Spine Necks
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DOI：
10.1371/journal.pone.0113916
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发表时间：
2014-12-10
期刊：
影响因子：
3.7
通讯作者：
Choquet, Daniel
中科院分区：
文献类型：
--
作者：
Ewers, Helge;Tada, Tomoko;Choquet, Daniel
树突棘上的兴奋性谷氨酸能突触通过侧膜扩散交换和调节其受体含量。多项研究表明，细长的脊椎颈部阻碍了膜和溶质分子进入脊椎头部。然而，目前尚不清楚脊柱颈部的几何形状是否单独限制了通往树突棘的途径，或者是否存在分子扩散的物理障碍。在这里，我们研究了定位于颈椎底部的一种SEPTIN细胞骨架GTP酶复合体是否调节了整个颈椎的扩散。我们发现，在发育过程中，Septin复合体的标记Septin7(9月7日)定位于脊柱颈部，在那里它在质膜下形成一个稳定的结构。我们发现，在颈部长有9月7的脊椎中，受体和体膜的扩散速度较慢，但细胞质蛋白的扩散速度较慢。最后，当通过RNA干扰抑制Sept7的表达时，膜分子探索了更大的膜区域。我们的发现表明，Sept7调控膜蛋白进入脊椎。
Excitatory glutamatergic synapses at dendritic spines exchange and modulate their receptor content via lateral membrane diffusion. Several studies have shown that the thin spine neck impedes the access of membrane and solute molecules to the spine head. However, it is unclear whether the spine neck geometry alone restricts access to dendritic spines or if a physical barrier to the diffusion of molecules exists. Here, we investigated whether a complex of septin cytoskeletal GTPases localized at the base of the spine neck regulates diffusion across the spine neck. We found that, during development, a marker of the septin complex, Septin7 (Sept7), becomes localized to the spine neck where it forms a stable structure underneath the plasma membrane. We show that diffusion of receptors and bulk membrane, but not cytoplasmic proteins, is slower in spines bearing Sept7 at their neck. Finally, when Sept7 expression was suppressed by RNA interference, membrane molecules explored larger membrane areas. Our findings indicate that Sept7 regulates membrane protein access to spines.