Mou T, Kraas J R, Fung E T, Swope S L
Department of Neurology, Georgetown Institute for Cognitive and Computational Sciences, Georgetown University Medical Center, Washington, DC 20007, USA.
FEBS Lett. 1998 Sep 18;435(2-3):275-81. doi: 10.1016/s0014-5793(98)01069-2.
The microtubule protein Tctex-1 was cloned from Torpedo electroplax, a biochemical model of the neuromuscular junction, using the unique domain of Fyn in the yeast two hybrid system. Binding of Tctex-1 and Fyn also occurred in vitro. Torpedo Tctex-1 was contained within the molecular motor protein dynein. A Src class kinase was also complexed with dynein. Tctex-1 was enriched in electric organ vs. skeletal muscle, was present in the postsynaptic membrane, and coprecipitated with the acetylcholine receptor. The sequence of Tctex-1 contained a tyrosine phosphorylation motif and Tctex-1 could be phosphorylated by Fyn in vitro and in vivo. These data demonstrated that Tctex-1-containing dynein is a cytoskeletal element at the acetylcholine receptor-enriched postsynaptic membrane and suggested that Tctex-1 may be a substrate for Fyn.
利用酵母双杂交系统中Fyn的独特结构域，从神经肌肉接头的生化模型——电鳐电器官中克隆出微管蛋白Tctex-1。Tctex-1与Fyn在体外也会发生结合。电鳐Tctex-1包含在分子运动蛋白动力蛋白中。一种Src类激酶也与动力蛋白形成复合物。与骨骼肌相比，Tctex-1在电器官中富集，存在于突触后膜，并与乙酰胆碱受体共沉淀。Tctex-1的序列包含一个酪氨酸磷酸化基序，并且Tctex-1在体外和体内均可被Fyn磷酸化。这些数据表明，含有Tctex-1的动力蛋白是富含乙酰胆碱受体的突触后膜处的一种细胞骨架成分，并提示Tctex-1可能是Fyn的底物。
