Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR)-5203, Institut de Génomique Fonctionnelle, Montpellier, F-34094, France.
J Neurosci. 2013 Jun 5;33(23):9699-715. doi: 10.1523/JNEUROSCI.2725-12.2013.
Synaptic long-term potentiation (LTP) is a key mechanism involved in learning and memory, and its alteration is associated with mental disorders. Shank3 is a major postsynaptic scaffolding protein that orchestrates dendritic spine morphogenesis, and mutations of this protein lead to mental retardation and autism spectrum disorders. In the present study we investigated the role of a new Shank3-associated protein in LTP. We identified the Rho-GAP interacting CIP4 homolog 2 (Rich2) as a new Shank3 partner by proteomic screen. Using single-cell bioluminescence resonance energy transfer microscopy, we found that Rich2-Shank3 interaction is increased in dendritic spines of mouse cultured hippocampal neurons during LTP. We further characterized Rich2 as an endosomal recycling protein that controls AMPA receptor GluA1 subunit exocytosis and spine morphology. Knock-down of Rich2 with siRNA, or disruption of the Rich2-Shank3 complex using an interfering mimetic peptide, inhibited the dendritic spine enlargement and the increase in GluA1 subunit exocytosis typical of LTP. These results identify Rich2-Shank3 as a new postsynaptic protein complex involved in synaptic plasticity.
突触长时程增强（LTP）是参与学习和记忆的关键机制，其改变与精神障碍有关。Shank3 是一种主要的突触后支架蛋白，它协调树突棘形态发生，该蛋白的突变导致智力迟钝和自闭症谱系障碍。在本研究中，我们研究了一种新的 Shank3 相关蛋白在 LTP 中的作用。我们通过蛋白质组筛选鉴定了 Rho-GAP 相互作用 CIP4 同源物 2（Rich2）作为 Shank3 的新伴侣。使用单细胞生物发光共振能量转移显微镜，我们发现 Rich2-Shank3 相互作用在培养的海马神经元的树突棘中在 LTP 期间增加。我们进一步将 Rich2 特征化为一种内体再循环蛋白，它控制 AMPA 受体 GluA1 亚基的胞吐作用和棘形态。使用 siRNA 敲低 Rich2 或使用干扰模拟肽破坏 Rich2-Shank3 复合物，抑制了树突棘的扩大和 LTP 中典型的 GluA1 亚基胞吐作用的增加。这些结果表明 Rich2-Shank3 是参与突触可塑性的新的突触后蛋白复合物。
