Kammer W, Lischke A, Moriggl R, Groner B, Ziemiecki A, Gurniak C B, Berg L J, Friedrich K
Theodor-Boveri-Institut für Biowissenschaften (Biozentrum), Physiologische Chemie II, Am Hubland, D-97074 Würzburg, Federal Republic of Germany.
J Biol Chem. 1996 Sep 27;271(39):23634-7. doi: 10.1074/jbc.271.39.23634.
The possible role of homodimerization events in intracellular signal transduction triggered by the bipartite human interleukin-4 receptor was addressed. We generated cell lines functionally expressing derivatives of the two receptor subunits alpha and gamma, which allow for a specific and background-free experimental induction of intracellular homo- and heterodimers. A heterodimer of alpha and gamma released an intracellular signal, whereas a gamma-gamma homodimer did not. Unexpectedly, we found the intracellular domain of interleukin-4 receptor alpha chain to evoke cell proliferation and activation of tyrosine kinase Jak1 as well as of transcription factor Stat6 upon homodimerization. Both recruitment of the common gamma chain and activation of kinase Jak3 were shown to be dispensible for these processes.
我们探讨了同二聚化事件在由双组分人白细胞介素-4受体触发的细胞内信号转导中可能发挥的作用。我们构建了功能性表达两个受体亚基α和γ衍生物的细胞系，这使得能够对细胞内同二聚体和异二聚体进行特异性且无背景的实验诱导。α和γ的异二聚体释放细胞内信号，而γ-γ同二聚体则不释放。出乎意料的是，我们发现白细胞介素-4受体α链的细胞内结构域在同二聚化时可引发细胞增殖以及酪氨酸激酶Jak1和转录因子Stat6的激活。结果表明，共同γ链的募集和激酶Jak3的激活对于这些过程都是不必要的。
