学习和记忆相关基因:Calsyntenins家族

Calsyntenins（Cstn）是一个独特的将胞外蛋白水解活性与胞内Ca^2＋信号转导相连在一起的家族,属于钙结合蛋白,与钙离子结合,参与信号转导和细胞交流。它包括3个成员,分别为calsyntenin-1、calsyntenin-2和calsyntenin-3,皆为突触后膜蛋白,主要在脑的神经元中表达,但表达模式各自不同,而且其蛋白也表现出高度的结构多样性。Calsyntenin-1位于中枢神经系统（CNS）突触后膜,是一个突触后膜蛋白水解的蛋白质。有一个结合钙的胞质酸性结构域,是一个通过胞外蛋白水解来调节突触后钙的动力调节子。Calsyntenin-1调节突触后膜下或胞内Ca^2＋储存库中的Ca^2＋瞬变,从而参与长时程增强（LTP）和长时程抑制（LTD）,与学习和记忆功能紧密相关。尤其是最近研究发现,β淀粉样蛋白前体（APP）和calsyntenins共同作用增加了β淀粉样蛋白（Aβ）的分泌,从而造成神经系统紊乱,促进阿尔采末病（AD）的发生,这对于AD发病机制的揭示和开发新一代治疗AD的药物具有重要的意义。

The family of calsyntenins: learning and memory related genes

Calsyntenins(Cst) comprise a family of transmembrane proteins with the unique potential to link extracellular proteolytic activity with intracellular Ca~(2 ) signaling.It is a molecular class of calcium binding protein,which can bind calcium ion and being involved in signal transduction and cell communication.It contains three members,calsyntenin-1,calsyntenin-2 and calsyntenin-3,which are postsynaptic membrane proteins and predominantly expressed in brain neurons.Each of the three calsyntenins exhibits a distinct neuronal mRNA expression pattern.The three calsyntenins exhibit the highest degree of structural diversity.The calsyntenin-1 is located in the postsynaptic membrane of CNS synapses and a proteolytically processed protein of the postsynaptic membrane with a calcium-binding cytoplasmic domain.Calsyntenin-1 is a dynamic modulator of postsynaptic calcium by extracellular proteolysis.Calsyntenin-1 may modulate Ca~(2 ) transients locally either beneath the postsynaptic membrane or around intracellular Ca~(2 ) stores,such as LTP and LTD.Recent studies showed that impairment of the coordinated metabolic regulation of APP and calsyntenins and the consequent loss of the reciprocal regulation by APP and calsyntenins in the gene transactivation could lead to neural disorders and disease progression in AD.This is important to disclose the mechanism of AD and develop new drugs for treating AD.