A H1 HISTONE GENE-SPECIFIC AC-BOX-RELATED ELEMENT INFLUENCES TRANSCRIPTION FROM A MAJOR CHICKEN H1 PROMOTER

In comparing several histone HI promoters, we have identified a highly conserved sequence element, 5'-TGTGTTA, located approx. 450-480 bp up stream from the cap site. This TG-box is a near perfect inverted repea t of the previously characterized AC-box (5'-AAACACA). The distance be tween these elements is also highly conserved. We performed transient transfection assays with cat gene reporter constructs which indicated that both the presence and correct position of the TG-box were essenti al for maximal expression of the chicken 02 H1 promoter. To the best o f our knowledge, this study represents the first demonstration of an e ffect by the TG-box on transcription of a major histone-encoding H1 ge ne.