NEGATIVE AND POSITIVE ELEMENTS IN THE PROMOTER REGION OF THE HUMAN APOFERRITIN L-GENE

We have characterized the promoter of the human gene coding for the ap oferritin L subunit. Transient transfections of 5' and 3' deletion mut ants indicate that the efficiency of the L promoter depends on both ne gative and positive cis-elements, located upstream and downstream of t he transcription start point. DNasel footprinting analysis of this DNA region revealed the presence of five protected segments. The most ups tream one (element 1) corresponds to the negative cis-element and is r ecognized by factor(s) sharing a GC-sequence specificity. Three positi ve elements are in the region upstream of the start of transcription; a fifth positive cis-element (element 5) is localized in the first exo n of the L gene. (C) 1995 Academic Press, Inc.