Molecular dynamics of STAT3 on IL-6 signaling pathway in living cells
Molecular dynamics of STAT3 on IL-6 signaling pathway in living cells
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DOI：
10.1016/j.bbrc.2004.09.187
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发表时间：
2004-11-26
影响因子：
3.1
通讯作者：
Uede, T
中科院分区：
文献类型：
--
作者：
Watanabe, K;Saito, K;Uede, T
信号转导子和转录激活子3（STAT 3）是白细胞介素-6（IL-6）信号转导的关键信号转导子。为了研究STAT 3复合物在活细胞中对IL-6信号传导的移动性和动力学，我们产生了由STAT 3融合增强型绿色荧光蛋白（STAT 3-GFP）组成的嵌合基因。STAT 3-GFP在Hep 3B细胞中表达，并通过荧光相关光谱分析该蛋白的动态变化。如前所述，IL-6刺激后，STAT 3从细胞质易位到细胞核。根据稳定转化体中STAT 3扩散的分析，在IL-6刺激后，细胞质膜和细胞质中的STAT 3分子的数量减少。在细胞核中，STAT 3复合物的扩散速度在IL-6刺激后强烈下降。此外，我们发现STAT 3在加入IL-6之前以分子量小于400 kDa的复合物形式存在。然而，IL-6刺激诱导形成的STAT 3二聚体作为megacomplex形式，其分子量超过1 MDa在细胞质和非常缓慢的扩散复合物在细胞核中。(C)2004年爱思唯尔公司All rights reserved.
Signal transducer and activator of transcription 3 (STAT3) is a critical signal transducer of interleukin-6 (IL-6) signaling. To investigate the mobility and the dynamics of STAT3 complex on IL-6 signaling in living cells, we generated a chimeric gene consisting of STAT3 fused to enhanced green fluorescence protein, STAT3-GFP. STAT3-GFP was expressed in Hep3B cells and the dynamics of this protein were analyzed by fluorescence correlation spectroscopy. After IL-6 stimulation, STAT3 translocated from the cytoplasm to the nucleus, as shown previously. According to the analysis of STAT3 diffusion in stable transformants, the number of STAT3 molecules at the cytoplasmic membrane and in the cytoplasm decreased after IL-6 stimulation. In the nucleus, the diffusion speed of STAT3 complex strongly decreased after IL-6 stimulation. Furthermore, we found that STAT3 existed as a complex whose molecular weight was less than 400 kDa before IL-6 addition. However, IL-6 stimulation induced the formation of STAT3 dimer as a megacomplex form whose molecular weight was more than 1 MDa at the cytoplasm and a very slow diffusion complex in the nucleus. (C) 2004 Elsevier Inc. All rights reserved.