Harada N, Higuchi K, Wakao H, Hamasaki N, Izuhara K
Department of Basic Research, Research Institute of Tuberculosis, Tokyo, Japan.
Biochem Biophys Res Commun. 1998 May 29;246(3):675-80. doi: 10.1006/bbrc.1998.8696.
Interleukin-4 (IL-4) has been shown to activate Janus kinase (Jak)-1 and Jak-3, followed by activation of STAT (signal transducers and activators of transcription) 6. This Jak-STAT pathway is central to the initiation of IL-4 activities. In this study, we identified the essential region for the proliferation signal and activation of Jak-1, Jak-3, and STAT6 in the cytoplasmic domain of the human IL-4 receptor alpha chain (hIL-4R alpha) using a mouse T cell line CTLL-2. We found that the region between amino acid 353 and 393 is critical for the proliferation signal and activation of STAT6, but not for tyrosine phosphorylation of Jaks. These results suggest that in addition to the "Box-1" portion, which is known to be essential for Jak-1 activation, the more membrane-distal region of hIL-4R alpha is also necessary for activation of STAT6.
白细胞介素-4（IL-4）已被证明可激活Janus激酶（Jak）-1和Jak-3，随后激活信号转导子和转录激活子（STAT）6。这种Jak-STAT途径是IL-4活性启动的核心。在本研究中，我们使用小鼠T细胞系CTLL-2确定了人IL-4受体α链（hIL-4Rα）胞质结构域中Jak-1、Jak-3和STAT6增殖信号及激活的关键区域。我们发现，氨基酸353至393之间的区域对增殖信号和STAT6的激活至关重要，但对Jaks的酪氨酸磷酸化并非如此。这些结果表明，除了已知对Jak-1激活至关重要的“Box-1”部分外，hIL-4Rα的更远膜端区域对于STAT6的激活也是必需的。
