STRUCTURE, SEQUENCE, AND CHROMOSOMAL LOCATION OF THE GENE FOR USF2 TRANSCRIPTION FACTORS IN MOUSE

The ubiquitously expressed upstream stimulatory factor (USF) involved in the transcription of a wide variety of cellular genes is defined as dimers of c-myc-related proteins, composed of a basic helix-loop-heli x/leucine zipper region. The USF family consists of different members that split into two groups: MLTF or USF1 and USF2 or FIP. We present h ere evidence that USF1 and USF2 are distinct closely related genes in human, rat, and mouse. Based on the recent cloning of rat and human ne w cDNAs, we have isolated genomic clones encompassing the murine USF2 gene, which consists of at least 10 exons spanning a minimum of 10 kb of genomic DNA. Unexpectedly, the organization of USF2 appears very sp lit up by introns (0.08 to over 6 kb in size), compared to the myc gen e structure. The entire gene (but the larger intron) and 1.6 kb of the 5' flanking region were sequenced. This 5' flanking region is GC-rich , contains several putative transcription binding sites, and has no ap parent TATA box. Gene mapping of murine USF2 and USF1 has been determi ned by in situ hybridization, indicating the localization of USF2 on c hromosome 7 and of USF1 on chromosomes 1 and 11. (C) 1995 Academic Pre ss, Inc.