Genetic Analysis of Hierarchical Regulation for Gata1 and NF-E2 p45 Gene Expression in Megakaryopoiesis
Genetic Analysis of Hierarchical Regulation for Gata1 and NF-E2 p45 Gene Expression in Megakaryopoiesis
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DOI：
10.1128/mcb.01304-09
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发表时间：
2010-03
影响因子：
5.3
通讯作者：
Mariko Takayama;Rie Fujita;Mikiko Suzuki;R. Okuyama;S. Aiba;H. Motohashi;Masayuki Yamamoto
中科院分区：
文献类型：
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作者：
Mariko Takayama;Rie Fujita;Mikiko Suzuki;R. Okuyama;S. Aiba;H. Motohashi;Masayuki Yamamoto
GATA 1和NF-E2 p45是巨核细胞发生的两个重要调控因子。而GATA 1是已知的调节p45基因，GATA 1对p45基因的时空表达的贡献的细节仍有待阐明。为了阐明GATA 1和p45之间的关系，我们利用Gata 1基因的造血调节结构域（G1 HRD）对巨核细胞中的p45功能进行了基因互补拯救分析。我们建立了在G1 HRD调控下表达p45的转基因小鼠系，并将小鼠与p45缺失小鼠杂交。化合物突变小鼠显示正常的血小板计数，没有出血的迹象，表明G1 HRD有能力以时空正确的方式表达p45。然而，从p45的N-末端区域的38个氨基酸的缺失废除了p45的救援功能，这表明在该区域中存在必要的反式激活活性。然后，我们将G1 HRD-p45转基因小鼠与巨核细胞特异性Gata 1基因敲除（Gata 1 ΔneoΔHS）小鼠杂交。G1 HRD-p45转基因不足以完全拯救Gata 1 ΔneoΔHS巨核细胞，这表明GATA 1或受GATA 1调控的其他因子需要与p45合作才能实现正常的巨核细胞生成。因此，这项研究提供了一个独特的在巨核细胞GATA 1和p45之间的层次关系的体内验证。
ABSTRACT GATA1 and NF-E2 p45 are two important regulators of megakaryopoiesis. Whereas GATA1 is known to regulate the p45 gene, details of the GATA1 contribution to the spatiotemporal expression of the p45 gene remain to be elucidated. To clarify the relationship between GATA1 and p45, we performed genetic complementation rescue analysis of p45 function in megakaryocytes utilizing the hematopoietic regulatory domain of the Gata1 gene (G1HRD). We established transgenic mouse lines expressing p45 under G1HRD regulation and crossed the mice with p45-null mice. Compound mutant mice displayed normal platelet counts and no sign of hemorrhage, indicating that G1HRD has the ability to express p45 in a spatiotemporally correct manner. However, deletion of 38 amino acids from the N-terminal region of p45 abrogated the p45 rescue function, suggesting the presence of an essential transactivation activity in the region. We then crossed the G1HRD-p45 transgenic mice with megakaryocyte-specific Gata1 gene knockdown (Gata1ΔneoΔHS) mice. The G1HRD-p45 transgene was insufficient for complete rescue of the Gata1ΔneoΔHS megakaryocytes, suggesting that GATA1 or other factors regulated by GATA1 are required to cooperate with p45 for normal megakaryopoiesis. This study thus provides a unique in vivo validation of the hierarchical relationship between GATA1 and p45 in megakaryocytes.