Babajko S, Groyer A
Unité de Recherches sur la Régulation de la Croissance, Institut National de la Santé et de la Recherche Médicale U.142, Hôpital Saint-Antoine, Paris, France.
Biochem Biophys Res Commun. 1993 Oct 15;196(1):480-6. doi: 10.1006/bbrc.1993.2275.
In the liver, expression of insulin-like growth factor binding protein-1 (IGFBP-1) is regulated essentially at the transcriptional level, at least in part by HNF1. In this study, the functional role of DBP and C/EBP (which have several potential binding sites on the IGFBP-1 proximal promoter) have been investigated. Transient co-transfection of the reporter plasmid, pBP-1341 and eukaryotic expression vectors which code for DBP and C/EBP in human cell lines Hep3B, HepG2 and C33 showed that IGFBP-1 promoter activity was unchanged by C/EBP, but increased between 2 and 7 times by DBP (depending on the cell line). In addition, DBP and HNF1 were capable of functional co-operation in activating the IGFBP-1 promoter. Our results support the notion of DBP being involved in limited tissue specificity of IGFBP-1 expression.
在肝脏中，胰岛素样生长因子结合蛋白-1（IGFBP-1）的表达主要在转录水平受到调控，至少部分是由肝细胞核因子1（HNF1）调控。在本研究中，已对DBP和C/EBP（它们在IGFBP-1近端启动子上有几个潜在结合位点）的功能作用进行了研究。在人细胞系Hep3B、HepG2和C33中，将报告质粒pBP-1341与编码DBP和C/EBP的真核表达载体进行瞬时共转染，结果显示，C/EBP对IGFBP-1启动子活性无影响，但DBP可使其活性增加2至7倍（取决于细胞系）。此外，DBP和HNF1在激活IGFBP-1启动子方面具有功能协同作用。我们的结果支持DBP参与IGFBP-1表达的有限组织特异性这一观点。
