Mapping of Sp1 regulation sites in the promoter of the human ?1-proteinase inhibitor gene

摘要: Keratoconus is a potentially blinding disease that thins the central cornea. In afflicted corneas, level of an inhibitor, α1-proteinase inhibitor (α1-PI), found reduced. An increased expression transcription factor Sp1 also demonstrated. To examine role in regulation human α1-PI gene, 1.4-kb (−1397/+9) 5′-flanking promoter sequence contains 10 sites was cloned. Previous transient transfection experiments showed indeed repressed activity. this study, 12 DNA segments, series 5′, 3′, and internal deletions sequence, were ligated into SEAP (secreted alkaline phosphatase) reporter gene vector transfected corneal stromal cells. Co-transfection with pPacSp1 performed parallel. The enzyme activity assayed. A fragment 489 bp (−480/+9) 3′ three fragments deletions, to confer majority full Other significantly abolished Site-directed mutagenesis further revealed most proximal site (−100/−87) may be essential element involved negative by Sp1. Interaction between distal seemed important. These results provide first in-depth characterization mechanisms regulating α1-PI. Mapping help elucidate molecular pathway leading alterations observed keratoconus. J. Cell. Biochem. 85: 482–489, 2002. © 2002 Wiley-Liss, Inc.