Hovis R R, Donovan J A, Musci M A, Motto D G, Goldman F D, Ross S E, Koretzky G A
Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242.
Science. 1993 Apr 23;260(5107):544-6. doi: 10.1126/science.8475387.
Surface expression of the CD45 tyrosine phosphatase is essential for the T cell antigen receptor (TCR) to couple optimally with its second messenger pathways. CD45 may be required to dephosphorylate a TCR-activated protein tyrosine kinase, which then transduces an activation signal from the TCR. A chimeric molecule that contained extracellular and transmembrane sequences from an allele of a major histocompatibility class I molecule and cytoplasmic sequences of CD45 restored TCR signaling in a CD45-deficient mutant T cell line. Thus, expression of the complex extracellular domain of CD45 is not required for the TCR to couple to its signaling machinery.
CD45 酪氨酸磷酸酶的表面表达对于 T 细胞抗原受体（TCR）与其二信使途径的最佳偶联至关重要。可能需要 CD45 使 TCR 激活的蛋白酪氨酸激酶去磷酸化，然后该激酶从 TCR 转导激活信号。一种嵌合分子，其包含来自主要组织相容性复合体 I 类分子一个等位基因的细胞外和跨膜序列以及 CD45 的细胞质序列，可在 CD45 缺陷的突变 T 细胞系中恢复 TCR 信号传导。因此，TCR 与其信号传导机制偶联并不需要 CD45 复杂细胞外结构域的表达。
