Kritis A A, Argyrokastritis A, Moschonas N K, Power S, Katrakili N, Zannis V I, Cereghini S, Talianidis I
Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Herakleion, Crete, Greece.
Gene. 1996 Sep 16;173(2):275-80. doi: 10.1016/0378-1119(96)00183-7.
Hepatocyte nuclear factor 4 (HNF-4) is an essential positive regulator of a large number of liver-specific genes. We report here the isolation of three HNF-4 isoforms from a human liver cDNA library. hHNF-4A and hHNF-4B, differing by the insertion of 10 amino acids in the C-terminal region, have been previously identified in mouse, rat and human liver. The novel isoform, hHNF-4C, is identical to hHNF-4A and B in the regions encompassing the DNA-binding and dimerization domains, but contains a different C-terminal domain. Similar to the other isoforms, hHNF-4C is produced in a limited number of tissues and represents 2.6-13% of the total hHNF-4 mRNA population, depending on the cell type. The chromosomal origin of all three isoforms has been localized to human chromosome 20. hHNF-4C can form heterodimers with hHNF-4A and B in vitro, and exhibits similar transactivation potential as hHNF-4A or B in transient transfection assays, suggesting that the divergent C-terminal region is not part of the transactivation domain.
肝细胞核因子4（HNF - 4）是大量肝脏特异性基因的重要正向调节因子。我们在此报告从人肝脏cDNA文库中分离出三种HNF - 4异构体。hHNF - 4A和hHNF - 4B在C末端区域插入了10个氨基酸，此前已在小鼠、大鼠和人肝脏中鉴定出来。新的异构体hHNF - 4C在包含DNA结合域和二聚化域的区域与hHNF - 4A和B相同，但含有不同的C末端结构域。与其他异构体相似，hHNF - 4C在有限数量的组织中产生，根据细胞类型不同，占hHNF - 4 mRNA总量的2.6% - 13%。所有三种异构体的染色体来源已定位到人类20号染色体。hHNF - 4C在体外可与hHNF - 4A和B形成异二聚体，并且在瞬时转染实验中表现出与hHNF - 4A或B相似的反式激活潜能，这表明不同的C末端区域不是反式激活域的一部分。
