Yang T H, Tsai W H, Lee Y M, Lei H Y, Lai M Y, Chen D S, Yeh N H, Lee S C
Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei.
Mol Cell Biol. 1994 Sep;14(9):6068-74. doi: 10.1128/mcb.14.9.6068-6074.1994.
Expression of the acute-phase response genes, such as that for alpha-1 acid glycoprotein (AGP), involves both positive and negative transcription factors. A positive transcription factor, AGP/EBP, and a negative transcription factor, factor B, have been identified as the two most important factors responsible for the induction of the AGP gene. In this paper we report the purification, characterization, and identification of a B-motif-binding factor from the mouse hepatoma cell line 129p. The purified factor has been identified as nucleolin by amino acid sequence analysis. Biochemical and functional studies further established that nucleolin is a transcription repressor for regulation of AGP and possibly other acute-phase response genes. Thus, in addition to the many known functions of nucleolin, such as rRNA transcription, processing, ribosome biogenesis, and the shuttling of proteins between the cytoplasmic and nuclear compartments, it may also function as a transcriptional repressor.
急性期反应基因的表达，比如α-1酸性糖蛋白（AGP）基因的表达，涉及正性和负性转录因子。一种正性转录因子AGP/EBP和一种负性转录因子B，已被确定为诱导AGP基因的两个最重要的因子。在本文中，我们报告了从小鼠肝癌细胞系129p中纯化、表征和鉴定一种B基序结合因子的过程。通过氨基酸序列分析，已将纯化的因子鉴定为核仁素。生化和功能研究进一步证实，核仁素是一种转录抑制因子，可调节AGP以及可能的其他急性期反应基因。因此，除了核仁素许多已知的功能，如rRNA转录、加工、核糖体生物发生以及蛋白质在细胞质和细胞核区室之间的穿梭外，它还可能作为一种转录抑制因子发挥作用。
