Species-specific regulation of the alpha-2(I) procollagen gene by proximal promoter elements.
Transcriptional regulation of the human alpha 2(I) procollagen proximal promoter involves the interaction of trans-acting factors at the inverted CCAAT box (G/CBE) located at position -80 and an adjacent GGAGGCCC-box at -70. Both these elements have previously been shown to be essential for activity of the human promoter. This study investigated nucleotide differences at three sites (-74, -72 and -71) between the human and mouse promoters that were sufficient to abolish trans-acting factor binding with the mouse sequence (GGAGACGT). Two distinct DNA-protein interactions were detected on the human -107/+54 promoter fragment while a single interaction was observed at the equivalent mouse promoter. One of these factors is the CCAAT-binding factor (CBF) and it's binding was observed on both the human and mouse promoters. Although the GGAGGCCC DNA-binding element was not detected on the mouse promoter, GGAGGCC-binding proteins were present in mouse nuclear extracts as observed by their interaction with the human promoter. Functional analysis of the human and mouse -343/+54 and -107/+54 promoter regions revealed significant differences between species; the human constructs having higher activity than the mouse. The differences in promoter activity between species may in part be a result of the nucleotide differences in the GGAGGCCC-box. Mutations in this region of the human -107/+54 promoter prevented DNA-protein interaction and lowered promoter activity. These results support the hypothesis that the GGAGGCCC-box in the human alpha 2(1) procollagen promoter has a regulatory function and that there exists a species-specific difference in transcription factor binding and regulation of the gene.
Leaner
Virna D
VD
Division of Medical Biochemistry, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa.
Masemola
Agatha
A
Parker
M Iqbal
MI
D020816:Amino Acid Motifs; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D024042:Collagen Type I / Q000737:chemistry* / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D019175:DNA Methylation; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D011347:Procollagen / Q000737:chemistry* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D013045:Species Specificity; D014158:Transcription, Genetic; D014162:Transfection
D024042:Collagen Type I; D011347:Procollagen; D004247:DNA