中文摘要：

GATA3（GA—TA-binding protein-3）是锌指蛋白GATA家族成员之一，在细胞的增殖和分化中起着重要的作用，GATA3在细胞中的异常表达也是导致众多肿瘤形成的原因。通过对GATA3mRNA5’非翻译区（untranslatedregion，uTR）进行分析，发现其UTR长达557bp并且具有复杂的二级结构。将GATA3mRNA5’UTR克隆至双荧光素酶报告载体pRL—FL中，瞬时转染至细胞中然后对细胞进行无血清培养后，发现GATA3mRNA5’UTR介导的翻译明显升高。将GATA3mRNA5’UTR克隆至△pRL—FL载体上，瞬时转染细胞后检测萤火虫荧光素酶的表达，发现GATA3mRNA5’UTR不具有隐含启动子，进而确定GATA3mRNA5’UTR具有内部核糖体进入位点（intemal ribosome entry sites，mES）元件；进一步对GATA3mRNA5’UTR进行序列截短分析，发现GATA3mRNA5’UTRq△345～557bp区间可能是抑制IRES活性的调控元件，而95～344bp区间则是IRES元件的主要活性中心调控域，并且在不同的细胞系中GATA3IRES元件的活性存在显著的差异。该研究结果表明，GATA3mRNA的5’UTR可参与GA]队3的表达调控。

英文摘要：

GATA3 is a member of GA-TA-binding protein family and plays an important role in cell proliferation and differentiation, and the abnormal expression of GATA3 in cells is also one cause of many tumor formations. In this paper, the mRNA 5＇ untranslated region （UTR） of GATA3 was analyzed, and it was found that the UTR was so long as 557 bp and had a complex secondary structure. When the mRNA 5＇ UTR of GATA3 was cloned into the bicistronic luciferase plasmid pRL-FL, it was found that the translation level of FL which was mediated by GATA3 mRNA 5＇ UTR was significantly augment under the condition of serum starvation. While the GATA3 mRNA 5＇ UTR was inserted into the bicistronic luciferase plasmid ApRL-FL and transient transfected into cells, the 5＇ UTR of GATA3 mRNA had no promoter activity according to the expression of firefly luciferase, which indicated that GATA3 mRNA 5＇ UTR had IRES element. By the truncated analysis of GATA3 mRNA 5＇ UTR sequence, it was revealed that the 345-557 bp might inhibit the IRES activity of GATA3 and the 95-344 bp might be the main active center of GATA3 mRNA IRES element. It was also found that this IRES activity was various in different cell lines. These results showed that the 5＇ UTR of GATA3 mRNA can participate in the regulation of GATA3 gene expression.