Covalent binding of guanine nucleotides to the CD3-gamma chain of the T cell receptor/CD3 complex.
Covalent binding of guanine nucleotides to the CD3-gamma chain of the T cell receptor/CD3 complex.
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鸟嘌呤核苷酸与 T 细胞受体/CD3 复合物的 CD3-γ 链共价结合。
DOI：
10.1002/eji.1830230224
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发表时间：
1993
影响因子：
5.4
通讯作者：
Terhorst,C
中科院分区：
文献类型：
--
作者：
Peter,ME;Wileman,T;Terhorst,C
在寻找通过T细胞受体（TcR/CD 3复合物）参与信号转导的蛋白质时，应用了最近开发的用于标记透化细胞中的核苷酸结合蛋白的高效方法。在这里，我们报告了人CD 3-γ可以被高碘酸盐氧化的[α-32 P] GTP（GTPoxi）标记。与⑶ 3-β的GTP环氧标记相反，（Peter，M. E、Hall，C，Ruhlmann，A.，Sancho，J.和Terhorst，C.，J. 1992.11：933），当在交联反应之前60分钟添加核苷酸时，⑶ 3-γ的GTP特异性标记达到最大值。由于CD 3-γ不含已知的核苷酸结合共有序列，并且由于CD 3-γ的标记动力学与胞质GTP结合蛋白的标记动力学一致，因此标记可能是由GTP结合蛋白引起的。这种推定的蛋白质不是T细胞特异性的，因为当在中国仓鼠卵巢（CHO）细胞的内质网中表达时，也可以实现CD 3-γ的标记。在CHO细胞中，GTPoxitook标记仅在CD 3-γ与CD 3-γ结合时进行，而在CD 3-γ与CD 3-δ或TcR α结合时无法建立标记。CD 3-γ被标记而不离开内质网的观察结果导致了这样的假设，即CD 3-γ与GTP结合蛋白的结合可能参与了TcR/CD 3复合物形成或转运的早期步骤。
In a search for proteins involved in signal transduction through the T cell receptor (TcR/CD3 complex), a recently developed highly efficient method for labeling of nucleotide binding proteins in permeabilized cells was applied. Here, we report that human CD3‐γ could be labeled by periodate‐oxidized [α‐32P] GTP (GTPoxi). In contrast to GTPoxilabeling of CD3‐ξ, (Peter, M. E., Hall, C, Ruhlmann, A., Sancho, J. and Terhorst, C,EMBOJ. 1992.11: 933), GTP‐specific labeling of CD3‐γ reached a maximum when nucleotides were added 60 min prior to the cross‐linking reaction. As CD3‐γ did not contain a known consensus sequence for nucleotide binding and since labeling kinetics of CD3‐γ coincided with those of cytosolic GTP‐binding proteins, labeling may have been caused by a GTP‐binding protein. This putative protein was not T cell specific because labeling of CD3‐γ could also be achieved when expressed in the endoplasmic reticulum of Chinese hamster ovary (CHO) cells. In CHO cells, labeling by GTPoxitook place only when CD3‐γ was associated with CD3‐ξ, whereas labeling could not be established upon association of CD3‐γ with CD3‐δ or TcR α. The observation that CD3‐γ was labeled without leaving the endoplasmic reticulum led to the hypothesis that the association of CD3‐γ with a GTP‐binding protein might be involved in an early step of the TcR/CD3 complex formation or transport.