Human regulatory factor X 4 (RFX4) is a testis-specific dimeric DNA-binding protein that cooperates with other human RFX members
Human regulatory factor X 4 (RFX4) is a testis-specific dimeric DNA-binding protein that cooperates with other human RFX members
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DOI：
10.1074/jbc.m108638200
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发表时间：
2002-01-04
影响因子：
4.8
通讯作者：
Miki, Y
中科院分区：
文献类型：
--
作者：
Morotami-Yano, K;Yano, K;Miki, Y
调节因子 X (RFX) 成员是进化上保守的转录因子，它们共享高度保守的翼状螺旋 DNA 结合域。人类 RFX4 已从乳腺癌中分离出来，作为编码与雌激素受体融合的短 RFX 型 DNA 结合结构域的部分 cDNA，但 RFX4 的整个结构尚不清楚。在此，我们报告了人 RFX4 的分子克隆和表征。 RFX4包含进化上保守的区域，包括RFX型DNA结合结构域、二聚化结构域和其他保守区域，并且在结构上与RFX1、RFX2和RFX3密切相关。 RFX4 的表达仅限于睾丸。体外合成的 RFX4 蛋白以序列依赖性方式与典型的 RFX 结合位点结合。免疫沉淀分析表明，RFX4 与 RFX2、RFX3 和 RFX4 本身发生物理相互作用，但不与 RFX1 发生相互作用。与形成二聚体的其他哺乳动物 RFX 成员相比，RFX4 没有明显的转录激活结构域。通过使用 RFX1 和 R 的嵌合蛋白，RFX4 的 C 端结构域被证明是可能的转录抑制结构域。综上所述，这些结果表明 RFX4 是 RFX 家族中第一个不具有转录激活能力的哺乳动物成员，并且可能通过与其他 RFX 成员选择性相互作用进行转录调节而发挥作用。
Regulatory factor X (RFX) members are evolutionarily conserved transcription factors that share a highly conserved winged helix DNA-binding domain. Human RFX4 has been isolated from breast cancer as a partial cDNA encoding a short RFX-type DNA-binding domain fused to the estrogen receptor, but the entire structure of RFX4 has been unknown. Here, we report the molecular cloning and characterization of human RFX4. RFX4 contains evolutionarily conserved regions, including a RFX-type DNA-binding domain, a dimerization domain, and other conserved regions, and is closely related to RFX1, RFX2, and RFX3 in structure. The expression of RFX4 is restricted to testis. In vitro synthesized RFX4 protein bound to typical RFX binding sites in a sequence-dependent manner. Immunoprecipitation analyses showed that RFX4 interacts physically with RFX2, RFX3, and RFX4 itself but not with RFX1. In contrast to other mammalian RFX members that form dimers, RFX4 is revealed to have no distinct transcriptional activation domains. By using a chimeric protein of RFX1 an R the C-terminal domain of RFX4 was shown to be a possible transcriptional repression domain. Taken together, these results indicate that RFX4 is the first mammalian member of RFX family without transcriptional activation capacity and might function through selective interactions with other RFX members in transcriptional regulation.