GATA-1 self-association controls erythroid development in vivo
GATA-1 self-association controls erythroid development in vivo
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DOI：
10.1074/jbc.m701936200
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发表时间：
2007-05-25
影响因子：
4.8
通讯作者：
Yamamoto, Masayuki
中科院分区：
文献类型：
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作者：
Shimizu, Ritsuko;Trainor, Cecelia D.;Yamamoto, Masayuki
加塔-1是红系、巨核细胞、嗜酸性粒细胞和肥大细胞谱系发育的关键转录因子。加塔-1具有自缔合的能力，并且该特性已被认为对于加塔-1功能是重要的。为了阐明自缔合加塔-1在体内造血细胞发育过程中的作用，在这项研究中，我们制备了加塔-1突变体，其中三个赖氨酸残基可能有助于自缔合（赖氨酸-245，赖氨酸-246和赖氨酸-312）被丙氨酸取代。在突变体中，在所有三个赖氨酸中具有丙氨酸取代的3 KA显示出降低的自缔合活性，而不显著干扰通过乙酰化修饰加塔-1。我们利用Gata 1造血调控结构域产生表达这些加塔-1突变体的转基因小鼠品系，并将小鼠与Gata 1敲低（加塔-1.05）突变小鼠杂交。尽管NKA（K245 A和K246 A）和CKA（K312 A）突变体几乎完全挽救了加塔-1.05小鼠的贫血和胚胎致死，但3 KA突变体仅部分挽救了加塔-1.05突变小鼠。即使在高于内源水平的表达下，加塔-1.05/Y：：3 KA胚胎在妊娠中晚期的各个阶段也易于死亡。活产和贫血表型在一些胚胎中恢复取决于3 KA转基因的表达水平。转铁蛋白受体和血红素生物合成酶的表达受损的卵黄囊和肝脏的3 KA拯救的胚胎。转铁蛋白受体表达不足的未成熟红系细胞在3 KA拯救的胚胎的肝脏中积累。这些结果提供了第一条令人信服的证据，即加塔-1的自缔合对于体内适当的哺乳动物红系发育是重要的。
GATA-1 is the key transcription factor for the development of the erythroid, megakaryocytic, eosinophilic, and mast cell lineages. GATA-1 possesses the ability to self-associate, and this characteristic has been suggested to be important for GATA-1 function. To elucidate the roles self-associated GATA-1 plays during hematopoietic cell development in vivo, in this study we prepared GATA-1 mutants in which three lysine residues potentially contributing to the self-association (Lys-245, Lys-246, and Lys-312) are substituted in combination with alanines. Of the mutants, 3KA harboring alanine substitutions in all three lysines showed reduced self-association activity without considerable interference in the modification of GATA-1 by acetylation. We generated transgenic mouse lines that express these GATA-1 mutants utilizing the Gata1 hematopoietic regulatory domain, and crossed the mice to Gata1 knockdown (GATA-1.05) mutant mice. Although NKA (K245A and K246A) and CKA (K312A) mutants almost fully rescued the GATA-1.05 mice from anemia and embryonic lethality, the 3KA mutant only partially rescued the GATA-1.05 mutant mice. Even with the higher than endogenous level expression, GATA-1.05/Y::3KA embryos were prone to die at various stages in mid-to-late gestation. Live birth and an anemic phenotype were restored in some embryos depending on the expression level of the 3KA transgene. The expression of the transferrin receptor and heme biosynthesis enzymes was impaired in the yolk sac and liver of the 3KA-rescued embryos. Immature erythroid cells with insufficient expression of the transferrin receptor accumulated in the livers of 3KA-rescued embryos. These results provide the first convincing line of evidence that the self-association of GATA-1 is important for proper mammalian erythroid development in vivo.