VWRPY motif-dependent and -independent roles of AML1/Runx1 transcription factor in murine hematopoietic development
VWRPY motif-dependent and -independent roles of AML1/Runx1 transcription factor in murine hematopoietic development
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DOI：
10.1182/blood-2003-06-2109
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发表时间：
2004-01-15
期刊：
影响因子：
20.3
通讯作者：
Okuda, T
中科院分区：
文献类型：
--
作者：
Nishimura, M;Fukushima-Nakase, Y;Okuda, T
AML 1/Runx 1是白血病相关基因畸变的常见靶点，它编码一种对确定性造血至关重要的转录因子。我们以前报道过，保留反式激活亚结构域的AML 1分子可以通过敲入方法表达，在体外拯救AML 1缺陷小鼠胚胎干细胞（ES）的造血缺陷。将这一概念扩展到体内条件下，我们发现，敲入的ES细胞克隆与AML 1突变体，保留反式激活亚结构域，但缺乏C-末端抑制亚结构域，包括保守的VWRPY基序，有助于嵌合体小鼠的造血组织。我们还发现，缺乏VWRPY基序的突变型AML 1等位基因纯合子的种系小鼠对造血发育的影响极小，与在具有全长AML 1的对照敲入小鼠中观察到的一样。另一方面，在VWRPY缺陷小鼠的T淋巴个体发育早期观察到细胞数量减少和异常的CD 4表达，而相应的ES细胞克隆对胸腺的贡献不足。这些发现表明，AML 1及其反式激活亚结构域是必需的，足以在整个小鼠的造血发育。此外，其反式阻遏活性，取决于C-末端VWRPY基序，在早期胸腺细胞发育中起作用。
AML1/Runx1 is a frequent target of leukemia-associated gene aberration, and it encodes a transcription factor essential for definitive hematopoiesis. We previously reported that the AML1 molecules with trans-activation subdomains retained can rescue in vitro hematopoietic defects of AML1-deficient mouse embryonic stem (ES) cells when expressed by using a knock-in approach. Extending this notion to in vivo conditions, we found that the knock-in ES cell clones with AML1 mutants, which retain trans-activation subdomains but lack C-terminal repression subdomains including the conserved VWRPY motif, contribute to hematopoietic tissues in chimera mice. We also found that germline mice homozygous for the mutated AML1 allele, which lacks the VWRPY motif, exhibit a minimal effect on hematopoietic development, as was observed in control knock-in mice with full-length AML1. On the other hand, reduced cell numbers and deviant CD4 expression were observed during early T-lymphoid ontogeny in the VWRPY-deficient mice, whereas the contribution to the thymus by the corresponding ES cell clones was inadequate. These findings demonstrate that AML1 with its trans-activating subdomains is essential and sufficient for hematopoietic development in the context of the entire mouse. In addition, its trans-repression activity, depending on the C-terminal VWRPY motif, plays a role in early thymocyte development.