Functional binding interaction identified between the axonal CAM L1 and members of the ERM family.
Functional binding interaction identified between the axonal CAM L1 and members of the ERM family.
复制标题
DOI：
10.1083/jcb.200111076
复制
发表时间：
2002-06-24
期刊：
影响因子：
--
通讯作者：
Salton SR
中科院分区：
文献类型：
--
作者：
Dickson TC;Mintz CD;Benson DL;Salton SR
利用轴突细胞粘附分子L1的细胞质结构域筛选了一个east双杂交文库，以确定可能参与L1功能调节的结合伙伴。细胞内L1的结构域与ezrin结合，ezrin是ezrin， radixin和moesin （ERM）膜-细胞骨架连接蛋白家族的成员，在重叠的位置与AP2重叠，AP2是网格蛋白适配器。细菌融合蛋白的结合证实了这种相互作用。为了确定ERM蛋白在体内是否与L1相互作用，使用L1的细胞外抗体迫使L1蛋白聚集在培养的海马神经元和PC12细胞上，然后对其进行ERM蛋白免疫标记。共聚焦分析显示，在轴突和PC12神经突中，erm和L1簇之间存在精确的共分布模式，而在树突和谱蛋白标记中，erm保持均匀分布。转染以负ERM结构为主的L1底物生长的海马神经元，会导致膜突起的广泛和异常细化，以及轴突分支的增加，这突出了ERM -肌动蛋白相互作用在轴突发育中的重要性。总之，我们的数据表明L1直接与ERM家族成员结合，并表明这种关联可能协调轴突形态发生的各个方面。
Ayeast two-hybrid library was screened using the cytoplasmic domain of the axonal cell adhesion molecule L1 to identify binding partners that may be involved in the regulation of L1 function. The intracellular domain of L1 bound to ezrin, a member of the ezrin, radixin, and moesin (ERM) family of membrane–cytoskeleton linking proteins, at a site overlapping that for AP2, a clathrin adaptor. Binding of bacterial fusion proteins confirmed this interaction. To determine whether ERM proteins interact with L1 in vivo, extracellular antibodies to L1 were used to force cluster the protein on cultured hippocampal neurons and PC12 cells, which were then immunolabeled for ERM proteins. Confocal analysis revealed a precise pattern of codistribution between ERMs and L1 clusters in axons and PC12 neurites, whereas ERMs in dendrites and spectrin labeling remained evenly distributed. Transfection of hippocampal neurons grown on an L1 substrate with a dominant negative ERM construct resulted in extensive and abnormal elaboration of membrane protrusions and an increase in axon branching, highlighting the importance of the ERM–actin interaction in axon development. Together, our data indicate that L1 binds directly to members of the ERM family and suggest this association may coordinate aspects of axonal morphogenesis.