Chagnovich D, Fayos B E, Cohn S L
Program in Tumor Cell Biology and Children's Memorial Hospital, Robert H. Lurie Cancer Center, Northwestern University Medical School, Chicago, Illinois 60611, USA.
J Biol Chem. 1996 Dec 27;271(52):33587-91. doi: 10.1074/jbc.271.52.33587.
Many short-lived mRNAs contain AU-rich instability elements within their 3'-untranslated region. Cellular factors that bind to these elements are thought to play a role in the regulation of mRNA degradation. In the accompanying paper (Chagnovich, D., and Cohn, S. L. (1996) J. Biol. Chem. 271, 33580-33586) we characterized the binding activity of a 40-kDa protein (p40) that interacts with high specificity with at least two AU-rich elements located within the 3'-untranslated region of N-myc. p40 activity correlates with N-myc mRNA stability in subclones of the NBL-W neuroblastoma cells line (W-N and W-S). In an effort to determine the identity of p40 we performed immunoblotting studies, immunoprecipitation experiments, and RNA gel mobility shift assays using antibodies that are directed against known RNA-binding proteins. In this paper we demonstrate that in W-N and W-S cells, p40 activity parallels the expression of embryonic letal abnormal vision (ELAV)-like proteins, and that antibodies directed against this family of RNA-binding proteins recognize p40. We also show that purified ELAV-like proteins (HuD and Hel-N1) bind with high specificity to the same N-myc 3'-untranslated region sequences as p40. Our data indicate that p40 is a member of the ELAV-like family, and suggest that this family of RNA-binding proteins may regulate N-myc mRNA turnover.
许多寿命较短的mRNA在其3'非翻译区内含有富含AU的不稳定元件。与这些元件结合的细胞因子被认为在mRNA降解的调控中发挥作用。在随附的论文中（Chagnovich, D.和Cohn, S. L.（1996年）《生物化学杂志》271, 33580 - 33586），我们对一种40 kDa蛋白质（p40）的结合活性进行了表征，该蛋白质与位于N - myc的3'非翻译区内的至少两个富含AU的元件具有高度特异性相互作用。p40活性与NBL - W神经母细胞瘤细胞系（W - N和W - S）的亚克隆中的N - myc mRNA稳定性相关。为了确定p40的身份，我们使用针对已知RNA结合蛋白的抗体进行了免疫印迹研究、免疫沉淀实验和RNA凝胶迁移率变动分析。在本文中，我们证明在W - N和W - S细胞中，p40活性与胚胎致死异常视觉（ELAV）样蛋白的表达平行，并且针对该RNA结合蛋白家族的抗体可识别p40。我们还表明，纯化的ELAV样蛋白（HuD和Hel - N1）与p40一样，对相同的N - myc 3'非翻译区序列具有高度特异性结合。我们的数据表明p40是ELAV样家族的成员，并提示该RNA结合蛋白家族可能调节N - myc mRNA的周转。
