Super-resolution microscopy reveals γ-secretase at both sides of the neuronal synapse.
Super-resolution microscopy reveals γ-secretase at both sides of the neuronal synapse.
复制标题
DOI：
10.1186/s40478-016-0296-5
复制
发表时间：
2016-03-31
影响因子：
7.1
通讯作者：
Tjernberg LO
中科院分区：
文献类型：
--
作者：
Schedin-Weiss S;Caesar I;Winblad B;Blom H;Tjernberg LO
跨膜蛋白组装γ-分泌酶是调节约100种1型跨膜蛋白的膜内加工（RIP）的关键蛋白酶。重要的是，它在阿尔茨海默病（AD）中具有病理作用，因为它从淀粉样前体蛋白（APP）产生神经毒性淀粉样β肽。因此，从生物学和治疗的角度来看，对γ-分泌酶定位的研究至关重要。尽管许多实验室进行了多年的努力，但仍不清楚γ-分泌酶在神经元中的何处发挥其活性。技术挑战包括活性酶含有四种蛋白质组分，并且大多数亚细胞区室不能通过传统光学显微镜进行空间分辨。在这里，我们使用了两种纳米显微镜技术STORM和STED显微镜的强大组合，使用活性位点特异性探针可视化神经元中γ-分泌酶的位置，重点是突触。我们发现，γ-分泌酶是目前在突触前和突触后的隔间。我们进一步表明，该酶富集非常接近突触后膜中的突触间隙，以及NMDA受体，表明γ-分泌酶存在于突触后质膜中。重要的是，γ-分泌酶在突触前和突触后区室中的表达随着突触的大小而增加，表明γ-分泌酶活性与突触成熟之间存在相关性。因此，我们的数据在三维空间中显示了高精度的突触位置，并解决了关于γ-分泌酶突触位置的长期争论。本文的在线版本（doi：10.1186/s40478-016-0296-5）包含补充材料，可供授权用户使用。
The transmembrane protein assembly γ-secretase is a key protease in regulated intramembrane processing (RIP) of around 100 type-1 transmembrane proteins. Importantly, it has a pathological role in Alzheimer disease (AD) as it generates the neurotoxic amyloid β-peptide from the amyloid precursor protein (APP). Studies on γ-secretase location are therefore crucial both from a biological and a therapeutic perspective. Despite several years of efforts in many laboratories, it is not clear where in the neuron γ-secretase exerts it’s activities. Technical challenges include the fact that the active enzyme contains four protein components and that most subcellular compartments cannot be spatially resolved by traditional light microscopy. Here, we have used a powerful combination of the two nanoscopy techniques STORM and STED microscopy to visualize the location of γ-secretase in neurons using an active-site specific probe, with a focus on the synapse. We show that γ-secretase is present in both the pre-and postsynaptic compartments. We further show that the enzyme is enriched very close to the synaptic cleft in the postsynaptic membrane, as well as to NMDA receptors, demonstrating that γ-secretase is present in the postsynaptic plasma membrane. Importantly, the expression of γ-secretase increased in the pre- and postsynaptic compartments with the size of the synapse, suggesting a correlation between γ-secretase activity and synapse maturation. Thus, our data shows the synaptic location with high precision in three dimensions and settles the long-lasting debate on the synaptic location of γ-secretase. The online version of this article (doi:10.1186/s40478-016-0296-5) contains supplementary material, which is available to authorized users.