THE HELIX-LOOP-HELIX TRANSCRIPTION FACTOR USF INTERACTS WITH THE BASAL PROMOTER OF HUMAN AMYLOID PRECURSOR PROTEIN

Nuclear factors from HeLa, PC12, NG108-15 and SK-N-SH cell lines recog nized an oligonucleotide (-56 to -37: APP-E1) containing an E box (CAN NTG) which had previously been characterized as a DNase I-protected se quence in the basal promoter of the human amyloid precursor protein (A PP) gene. Binding to APP-E1 was competed with an oligonucleotide encom passing the recognition site of the transcription factor USF. Antibodi es directed against USF interacted with the APP-E1-protein complex and in vitro synthesized USF could bind APP-E1. Co-expression of USF cDNA transactivated a human APP-reporter gene construct. These results sug gest that USF may play a role in the expression of the APP gene.