Characterization of proteins binding the 3' regulatory region of the IL-3 gene in IL-3-dependent and autocrine-transformed hematopoietic cells.
Characterization of proteins binding the 3' regulatory region of the IL-3 gene in IL-3-dependent and autocrine-transformed hematopoietic cells.
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IL-3 依赖性造血细胞和自分泌转化造血细胞中与 IL-3 基因 3 调节区结合的蛋白质的表征。
DOI：
10.1038/sj.leu.2400975
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发表时间：
1998
期刊：
影响因子：
11.4
通讯作者：
McCubrey,JA
中科院分区：
文献类型：
--
作者：
Wang,XY;Hoyle,PE;McCubrey,JA
以前，我们记录了IL-3 mRNA的半衰期在自分泌转化的细胞系中的延长。该细胞系在IL-3 mRNA 3 ′非翻译区有一个脑池内A型颗粒转座，它取代了参与IL-3 mRNA不稳定的6个AUUUA基序中的4个。本研究检测了IL-3 mRNA富含AU元件（ARE）的结合蛋白。检测到与含有6个AUUUA基序（Au 6）的野生型IL-3 ARE区的特异性蛋白结合。相反，未检测到与仅含有两个AUUUA基序（Au 2）的突变的IL-3 ARE区的结合。表观分子量为36、40、43、46、55、57、68和95 kDa的蛋白质与Au 6基序结合。hnRNP C和AUF-1（hnRNP D）蛋白被确定为IL-3 ARE结合蛋白中的两种。将蛋白提取物与hnRNP C和AUF-1的抗体孵育显著降低了蛋白与IL-3 ARE的结合。用钙离子载体处理IL-3依赖性细胞消除了与野生型IL-3依赖性FL5中的ARE结合的蛋白质。12个细胞，并导致IL-3 mRNA转录本的积累具有长的半衰期。结果表明，IL-3mRNA 3 ′ ARE与IL-3mRNA 3 ′ ARE结合有特异性复合物。截短IL-3 ARE的突变消除了蛋白质结合该调节区的能力，并且由于具有长半衰期的IL-3 mRNA转录物的存在而可导致自分泌转化。
Previously we documented the prolongation of the IL-3 mRNA half-life in an autocrine-transformed cell line. This cell line has an intracisternal type A particle transposition in the IL-3 mRNA 3′ untranslated region which displaced four out of six AUUUA motifs involved in IL-3 mRNA destabilization. In this study, the proteins binding to the IL-3 mRNA AU-rich elements (ARE) were examined. Specific protein binding was detected to the wild-type IL-3 ARE region which contained 6 AUUUA motifs (AU 6). In contrast, no binding was detected to the mutated IL-3 ARE region which contained only two AUUUA motifs (AU 2). Proteins with apparent molecular weights of 36, 40, 43, 46, 55, 57, 68 and 95 kDa were bound to AU 6 motif. The hnRNP C and AUF-1 (hnRNP D) proteins were determined to be two of the IL-3 ARE binding proteins. Incubation of protein extracts with antibodies to hnRNP C and AUF-1 significantly decreased the protein binding to the IL-3 ARE. Treatment of IL-3 dependent cells with calcium ionophores eliminated the proteins binding to the ARE in wild-type IL-3-dependent FL5. 12 cells and also resulted in the accumulation of IL-3 mRNA transcripts with a long half-life. These results indicated that there was a specific complex which bound the IL-3 mRNA 3′ ARE. Mutations which truncate the IL-3 ARE eliminate the ability of proteins to bind this regulatory region and can result in autocrine transformation due to the presence of IL-3 mRNA transcripts with a long half-life.