Targeted disruption of the CP2 gene, a member of the NTF family of transcription factors
Targeted disruption of the CP2 gene, a member of the NTF family of transcription factors
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DOI：
10.1074/jbc.m004351200
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发表时间：
2001-03-16
影响因子：
4.8
通讯作者：
Jane, SM
中科院分区：
文献类型：
--
作者：
Ramamurthy, L;Barbour, V;Jane, SM
转录因子的ntf样家族已经涉及到发育调节的生物多样性，如果蝇和人类。该家族的两个哺乳动物成员CP2 （LBP-1c/LSF）和LBP-1a （NF2d9）是高度相关的蛋白，氨基酸同源度为72%。CP2是这些因子中最具特征的，是一种普遍表达的66-kDa蛋白，它结合了许多不同基因的调控区域。因此，CP2在珠蛋白基因表达、t细胞对有丝分裂刺激的反应以及其他一些细胞过程中发挥了作用。为了阐明CP2在体内的作用，我们培育了CP2等位基因为零合子的小鼠，这些小鼠出生时呈正态孟德尔分布，在生长、行为、生育或发育方面没有缺陷。具体来说，没有观察到造血分化、珠蛋白基因表达或T细胞和b细胞有丝分裂刺激的免疫反应的扰动。RNA和蛋白质分析证实，失合小鼠没有表达CP2的全长或截短版本。用多个组织的核提取物进行的电泳迁移转移试验表明-/-系中CP2 DNA结合活性的丧失。然而，用抗血清消融LBP-1a的小鼠同源物NF2d9，观察到这些提取物具有较慢的迁移复合物。此外，我们证明重组LBP-1a可以结合已知的CP2共识位点，并与先前定义的CP2异质伴侣形成蛋白复合物。这些结果表明，LBP-1a/NF2d9可能弥补了体内CP2表达的缺失，进一步分析NTF蛋白家族的作用需要靶向NF2d9基因。
The NTF-like family of transcription factors have been implicated in developmental regulation in organisms as diverse as Drosophila and man. The two mammalian members of this family, CP2 (LBP-1c/LSF) and LBP-1a (NF2d9), are highly related proteins sharing an overall amino acid identity of 72%. CP2, the best characterized of these factors, is a ubiquitously expressed 66-kDa protein that binds the regulatory regions of many diverse genes. Consequently, a role for CP2 has been proposed in globin gene expression, T-cell responses to mitogenic stimulation, and several other cellular processes. To elucidate the in vivo role of CP2, we have generated mice nullizygous for the CP2 allele, These animals were born in a normal Mendelian distribution and displayed no defects in growth, behavior, fertility, or development. Specifically, no perturbation of hematopoietic differentiation, globin gene expression, or immunological responses to T- and B-cell mitogenic stimulation was observed. RNA and protein analysis confirmed that the nullizygous mice expressed no full-length or truncated version of CP2. Electrophoretic mobility shift assays with nuclear extracts from multiple tissues demonstrated loss of CP2 DNA binding activity in the -/- lines. However, a slower migrating complex that was ablated with antiserum to NF2d9, the murine homologue of LBP-1a, was observed with these extracts. Furthermore, we demonstrate that recombinant LBP-1a can bind to known CP2 consensus sites and form protein complexes with previously defined heteromeric partners of CP2. These results suggest that LBP-1a/NF2d9 may compensate for loss of CP2 expression in vivo and that further analysis of the role of the NTF family of proteins requires the targeting of the NF2d9 gene.