Aperlo C, Boulukos K E, Sage J, Cuzin F, Pognonec P
INSERM U 273, Laboratoire de Biochimie, Université de Nice, France.
Genomics. 1996 Nov 1;37(3):337-44. doi: 10.1006/geno.1996.0568.
USF is a transcription factor able to stimulate promoter activity upon binding to an upstream sequence identical to that recognized by the protooncogene Myc. However, despite extensive biochemical characterization, nothing is known concerning its physiological function. A USF-related protein able to interact with Fos and known as FIP/USF2 has been reported. Its genomic structure in mouse has been recently characterized. We present here the cloning and characterization of the murine USF gene. It consists of 10 exons, the first of which is noncoding, and the gene spans 8 kb of DNA. We show that the murine USF protein is almost identical to its human counterpart, but that an intron not conserved between human and murine USF genes curiously has been conserved between human USF and murine FIP/USF2. Otherwise, the splicing pattern of murine USF and FIP/USF2 is exactly conserved. We also demonstrate that the murine USF promoter is located more than 2.5 kb upstream of the first coding ATG, in a region displaying divergent promoter activity. Finally, we show that an Mx1-related sequence is present less than 3 kb downstream of the murine USF gene, in a tail-to-tail position. Taken together, these data indicate that the murine USF gene is very similar to the murine FIP/USF2 gene and is potentially bracketed by two other transcription units on the other DNA strand.
USF是一种转录因子，它在与原癌基因Myc识别的上游序列结合后能够刺激启动子活性。然而，尽管对其进行了广泛的生化特性分析，但关于其生理功能仍一无所知。据报道，有一种与USF相关的蛋白质能够与Fos相互作用，称为FIP/USF2。其在小鼠中的基因组结构最近已被鉴定。我们在此展示小鼠USF基因的克隆和特性分析。它由10个外显子组成，其中第一个是非编码的，该基因跨越8kb的DNA。我们表明，小鼠USF蛋白与其人类对应物几乎相同，但人类和小鼠USF基因之间不保守的一个内含子奇怪地在人类USF和小鼠FIP/USF2之间保守。否则，小鼠USF和FIP/USF2的剪接模式完全保守。我们还证明，小鼠USF启动子位于第一个编码ATG上游超过2.5kb处，处于一个显示出不同启动子活性的区域。最后，我们表明在小鼠USF基因下游不到3kb处存在一个与Mx1相关的序列，处于尾对尾位置。综上所述，这些数据表明小鼠USF基因与小鼠FIP/USF2基因非常相似，并且在另一条DNA链上可能被另外两个转录单元包围。
