The Wilms' tumor gene WT1 can regulate genes involved in sex determination and differentiation: SRY, Müllerian-inhibiting substance, and the androgen receptor.
The Wilms' tumor gene WT1 can regulate genes involved in sex determination and differentiation: SRY, Müllerian-inhibiting substance, and the androgen receptor.
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发表时间：
1997-12
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通讯作者：
R. Shimamura;G. Fraizer;J. Trapman;Lau YfC;G. Saunders
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作者：
R. Shimamura;G. Fraizer;J. Trapman;Lau YfC;G. Saunders
WAGR和Denys-Drash综合征中与Wilms肿瘤相关的生殖器异常以及Wilms肿瘤基因（wt1）纯合突变小鼠性腺发育失败提示wt1也可能在性发育中起作用。为了阐明WT1在胚胎性发育中的作用机制，我们使用共转染法研究了WT1的四种同工异构体如何调节与性发育有关的几个基因的转录。SRY （Y染色体上的性别决定区）启动子被不含KTS三肽的WT1(-)KTS强烈激活，但在所有测试的细胞中，不被含KTS三肽的WT1(+)KTS的WT1同工型激活。第二个备选剪接位点插入三肽KTS，改变了DNA的结合能力。m<s:1>阿杜勒抑制物质（MIS）启动子在Sertoli细胞中受到WT1(-)KTS亚型的强烈抑制，而在HeLa细胞中受到WT1(+)KTS亚型的较弱抑制。雄激素受体（AR）启动子在所有细胞中都受到WT1(-)KTS亚型的强烈抑制，而WT1(+)KTS亚型的抑制则较弱或不受抑制，这取决于细胞系。电泳迁移位移实验显示重组WT1(-)KTS蛋白与含有这三个启动子的WT1结合位点的DNA探针结合较强，而WT1(+)KTS蛋白与DNA探针的结合较弱或没有结合。这些功能和结合试验的结果表明，WT1在胚胎性发育相关基因的调控中具有重要作用，并且WT1可以作为转录激活因子发挥作用。
Genital abnormalities associated with Wilms' tumors in the WAGR and Denys-Drash syndromes and the failure of the gonads to develop in Wilms' tumor gene (wt1)-homozygous mutant mice suggest that WT1 may also function in sexual development. To elucidate the mechanism of action of WT1 in embryonal sexual development, we examined how the four isoforms of WT1 regulate the transcription of several genes involved in sexual development using cotransfection assays. SRY (the sex-determining region of the Y chromosome) promoter was strongly activated by the WT1 isoforms without the KTS tripeptide, WT1(-)KTS, but was not activated by the WT1 isoforms with the KTS tripeptide, WT1(+)KTS, in all cells tested. The second alternative splicing site, which inserts the tripeptide KTS, alters the DNA binding capability. The MüAdullerian-inhibiting substance (MIS) promoter was strongly repressed by WT1(-)KTS isoforms and more weakly repressed by the WT1(+)KTS isoforms in Sertoli cells but not in HeLa cells. The androgen receptor (AR) promoter was strongly repressed by the WT1(-)KTS isoforms in all cells tested and was more weakly or not repressed by WT1(+)KTS isoforms depending on cell lines. Electrophoretic mobility shift assays showed strong binding by recombinant WT1(-)KTS protein and weaker or no binding by the WT1(+)KTS protein to DNA probes containing WT1 binding sites from these three promoters. The results of these functional and binding assays suggest that WT1 has an important role in regulation of genes involved in embryonal sexual development and that WT1 can function as a transcriptional activator.