The mouse bone morphogenetic protein-4 gene. Analysis of promoter utilization in fetal rat calvarial osteoblasts and regulation by COUP-TFI orphan receptor.
Bone morphogenetic protein-4 (BMP-4) is one of a member of related polypeptides that are important in bone formation and other developmental processes. We isolated the BMP-4 gene from a mouse genomic library and characterized the exon-intron structure and one of the candidate promoters. Two alternative 5'-noncoding exons, 1A and 1B, were identified by reverse transcription polymerase chain reaction assays. Quantitative competitive polymerase chain reaction using Exon 1A, Exon 1B, and Exon 3 primers indicate the 1A-containing transcript is the primary BMP-4 mRNA expressed in bone cell cultures. Primer extension analysis supports that 1A is the major promoter utilized in bone cell cultures as well as in 9.5-day mouse embryos. 1A promoter activity indicate selective DNA regions functional in bone cells. We found potential regulatory response regions in the 1A 5'-flanking region of the BMP-4 gene for the chicken ovalbumin upstream-transcription factor I (COUP-TFI). Specific binding to the COUP-TFI response regions in the BMP-4 1A promoter was demonstrated. By co-transfection of a COUP-TFI expression plasmid with the BMP-4 1A promoter in fetal rat calvarial osteoblasts, we demonstrated that COUP-TFI inhibits the BMP-4 promoter activity. This suggests that COUP-TFI could act as a silencer for BMP-4 transcription in vivo.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D019485:Bone Morphogenetic Proteins; D051838:COUP Transcription Factor I; D002478:Cells, Cultured; D002645:Chickens; D003001:Cloning, Molecular; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism; D004622:Embryo, Mammalian; D004625:Embryo, Nonmammalian; D005091:Exons; D005333:Fetus; D005786:Gene Expression Regulation; D006133:Growth Substances / Q000096:biosynthesis / Q000235:genetics; D007700:Kinetics; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D010006:Osteoblasts / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis; D012886:Skull; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection
D019485:Bone Morphogenetic Proteins; D051838:COUP Transcription Factor I; D017931:DNA Primers; D004268:DNA-Binding Proteins; D006133:Growth Substances; C497590:Nr2f1 protein, mouse; C497591:Nr2f1 protein, rat; D011506:Proteins; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; D011994:Recombinant Proteins; D014157:Transcription Factors