CD45是表达于所有造血干细胞来源的有核细胞表面的一个同源二聚体分子。它具有蛋白酪氨酸磷酸水解酶活性,可通过调节一系列底物蛋白的磷酸化程度来参与T细胞活化。另外,它还直接与T细胞表面其它分子发生关系,作用于T细胞。关于CD45分子的作用机制虽然已有了初步了解,但仍然有许多问题尚待解决。 CD45 is a homodimeric molecule expressed on the surface of all hematopoietic stem cell-derived nucleated cells. It has protein tyrosine phosphohydrolase activity and can be involved in T cell activation by regulating the phosphorylation of a series of substrate proteins. In addition, it also directly related to other molecules on the T cell surface, acting on T cells. Although there is a preliminary understanding of the mechanism of action of CD45 molecules, many problems remain to be solved.