Analysis of the collagen alpha 1(I) promoter.

The collagen alpha 1(I) gene is regulated at a developmental and tissue specific level. We have previously demonstrated that only 220bp of the promoter region of the collagen alpha 1(I) gene are required for efficient expression in NIH 3T3 cells. DNAse I protection assays demonstrated 4 footprinted segments in the promoter region. Deletional analysis revealed that the 3 most proximal footprints were required for maximal expression. The most proximal footprint contains a CCAAT sequence and a 12bp segment that forms a direct repeat with the preceding footprint. Ligation of the proximal footprint sequence to a heterologous promoter enhanced transcription of the reporter gene. These studies, therefore, identify and characterize elements in the promoter region of the collagen alpha 1(I) gene that interact with DNA binding proteins and are required for efficient expression.