Hirose T, Fujimoto W, Tamaai T, Kim K H, Matsuura H, Jetten A M
Cell Biology Section, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
Mol Endocrinol. 1994 Dec;8(12):1667-80. doi: 10.1210/mend.8.12.7708055.
Using polymerase chain reaction and two degenerate primers whose designs were based on the two best conserved regions of the DNA-binding domain of the nuclear receptor superfamily, we identified and cloned a novel orphan receptor, named TAK1. The open reading frame of TAK1 encodes a protein of 596 amino acid residues. Based on the modular structure and the presence of a DNA-binding domain containing two zinc fingers TAK1 belongs to the steroid/thyroid hormone receptor superfamily. The amino acid sequence of TAK1 is most closely related to the orphan receptor TR2-11. Their overall sequence homology is 64%, with the highest similarity (82%) being observed in the DNA-binding domain. Northern blot analysis using RNA from multiple human tissues showed that a 9.4 kilobase TAK1 transcript was expressed ubiquitously and that the presence of a 2.8 kilobase mRNA was largely restricted to the testis. In situ hybridization using sections of rat and mouse testes and Northern blot analysis using RNA from testes of rats at various ages revealed that TAK1 is most abundantly expressed in spermatocytes whereas little expression was observed in other germ cells or somatic cells. In situ hybridization using other mouse and rat tissues revealed cell type-specific expression of TAK1 in several tissues. Our observations suggest a role for this putative transcription factor in the regulation of gene expression in specific cell types. In the testis, TAK1 appears to control gene expression during spermatogenesis, particularly during the meiotic phase.
我们使用聚合酶链反应以及基于核受体超家族DNA结合域的两个最佳保守区域设计的两个简并引物，鉴定并克隆了一种新型孤儿受体，命名为TAK1。TAK1的开放阅读框编码一个由596个氨基酸残基组成的蛋白质。基于其模块化结构以及存在包含两个锌指的DNA结合域，TAK1属于类固醇/甲状腺激素受体超家族。TAK1的氨基酸序列与孤儿受体TR2-11最为密切相关。它们的整体序列同源性为64%，在DNA结合域中观察到的相似性最高（82%）。使用来自多种人类组织的RNA进行的Northern印迹分析表明，一个9.4千碱基的TAK1转录本在各处均有表达，而一个2.8千碱基的mRNA主要局限于睾丸中。使用大鼠和小鼠睾丸切片进行的原位杂交以及使用不同年龄大鼠睾丸的RNA进行的Northern印迹分析表明，TAK1在精母细胞中表达最为丰富，而在其他生殖细胞或体细胞中几乎没有表达。使用其他小鼠和大鼠组织进行的原位杂交揭示了TAK1在几种组织中的细胞类型特异性表达。我们的观察结果表明，这种假定的转录因子在特定细胞类型的基因表达调控中发挥作用。在睾丸中，TAK1似乎在精子发生过程中，特别是在减数分裂阶段，控制基因表达。
