Molecular Biology of the Ribonuclease A Gene Superfamily

在本报告期间，我们研究了GATA-1和GATA-2在激活分泌型核糖核酸酶-嗜酸性粒细胞衍生神经毒素(EDN/RNase2)转录中的作用。在嗜酸性粒细胞中检测到GATA-1和GATA-2的表达增强，EDN/RNase2基因延伸的5‘启动子中两个共同的GATA结合位点之一或两者的缺失或突变导致报告基因活性显著降低。抗体增强的电泳迁移率改变和染色质免疫沉淀分析表明，GATA-1和GATA-2蛋白与EDN启动子中的两个GATA共同序列结合。有趣的是，GATA-1的RNA沉默对EDN/RNase2的表达没有影响；GATA-2的沉默导致EDN的表达减少，同时在丁酸诱导的HL-60克隆15细胞和CD34()造血祖细胞来源的人嗜酸性粒细胞分化过程中GATA-1的表达也减少。同样，GATA-2的过表达导致EDN/RNase2和GATA-1的转录增强。综上所述，我们的数据表明GATA-2直接通过与EDN启动子的相互作用发挥作用，也通过其在分化嗜酸性粒细胞过程中调节GATA-1的表达而间接发挥作用(邱等人。J生物化学。2009年)。 另一份出版物关注哺乳动物核糖核酸酶的多样性，完成了魏昭博士作为我们团队客座教授的一些杰出工作。这份手稿识别了一组新的啮齿动物RNase1基因，也用于补充和纠正GenBank数据库中的几个错误条目(Siegel等人。Mamm Genome，2009，正在印刷中) 我继续担任《生物化学杂志》的编辑委员会(自2008年以来)，这在很大程度上是因为我在核糖核酸酶生物学和生物化学方面的专业知识。

During this reporting period, we examined the roles of GATA-1 and GATA-2 in activating transcription of the secretory ribonuclease, the eosinophil-derived neurotoxin (EDN/RNase 2). Augmented expression of both GATA-1 and GATA-2 was detected in eosinophils and deletion or mutation of one or both of the two consensus GATA-binding sites in the extended 5' promoter of the EDN/RNase2 gene resulted in profound reduction in reporter gene activity. Antibody-augmented electrophoretic mobility shift and chromatin immunoprecipitation analyses indicate that GATA-1 and GATA-2 proteins bind to both functional GATA consensus sequences in the EDN promoter. Interestingly, RNA silencing of GATA-1 alone had no impact on EDN/RNase2 expression; silencing of GATA-2 resulted in diminished expression of EDN, and also diminished expression of GATA-1 in both butyric acid-induced HL-60 clone 15 cells and in differentiating human eosinophils derived from CD34(+) hematopoietic progenitors. Likewise, overexpression of GATA-2 in resulted in augmented transcription of both EDN/RNase2 and GATA-1. Taken together, our data suggest that GATA-2 functions directly via interactions with the EDN promoter and also indirectly, via its ability to regulate the expression of GATA-1 in differentiating eosinophils (Qiu et al. J Biol Chem. 2009). Another publication focuses on the diversity of mammalian RNase A ribonucleases, and completes some outstanding work from Dr. Wei Zhao's visiting professorship with our group. This manuscript, which identifies a novel cluster of rodent RNase 1 genes, serves also to complete and to correct several erroneous entries in GenBank database (Siegel et al. Mamm Genome, 2009, in press) I continue to serve on the Editorial Board of Journal of Biological Chemistry (since 2008), a largely due to my expertise in Ribonuclease Biology and Biochemistry.