MULTIPLE CIS-ACTING ELEMENTS OF THE PROXIMAL PROMOTER REGION ARE REQUIRED FOR BASAL LEVEL TRANSCRIPTION OF THE H1(0) HISTONE GENE

Basal level transcription of the mouse histone H10 gene is mediated by 531 base pairs of the promoter region. Deletion of the most distal upstream 80 by of this fragment reduces transcription to very low values. By in vitro footprinting we demonstrate now that multiple factors bind to the DNA fragment localized between the 80 by and the cap nucleotide. In addition to the presence of motifs for the binding of SP1, H1-box, H4TF-2 and TATA-box-factors, other not yet described protein-binding elements were identified. Internal deletions in the wild type promoter enclosing these motifs strongly restrict transcription. Furthermore, when one of these motifs was modified by site-directed mutagenesis a strong impairment of transcription followed. Thus for basal level transcription, in addition to the 80 by distal fragment, cis-acting elements localized in the 450 bp proximal promoter region are required. © 1992.