Identification and functional characterization of distinct critically important bone morphogenetic protein-specific response elements in the Id1 promoter.
Transforming growth factor-beta (TGF-beta) family members, which include bone morphogenetic proteins (BMPs) and TGF-betas, elicit their cellular effects by activating specific Smad proteins, which control the transcription of target genes. BMPs and TGF-betas have overlapping as well as specific effects on mesenchymal cell differentiation for which the mechanisms are incompletely understood. Here we report that Id1, a dominant negative inhibitor of basic helix-loop-helix proteins, is a direct target gene for BMP. BMP, but not TGF-beta, strongly activates the Id1 promoter in an Smad-dependent manner. We identified two BMP-responsive regions in the mouse Id1 promoter, which contain three distinct sequence elements; one region contains two Smad binding elements (SBEs), and the other region contains a GGCGCC palindromic sequence flanked by two CAGC and two CGCC motifs. Whereas SBEs and GGCGCC sequence are critically important, the CAGC and CGCC motifs are needed for efficient BMP-induced Id1 promoter activation. Smads are part of nuclear transcription factor complexes that specifically bind to SBEs and GGCGCC sequence in response to BMP but not TGF-beta. Multimerization of the all three distinct sequence motifs is needed to generate a highly sensitive and BMP/Smad-dependent specific enhancer. Our results provide important new insights into how the BMP/Smad pathway can specifically activate target genes.
Korchynskyi
Olexander
O
Division of Cellular Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
ten Dijke
Peter
P
D020816:Amino Acid Motifs; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D019485:Bone Morphogenetic Proteins / Q000737:chemistry*; D002454:Cell Differentiation; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D017930:Genes, Reporter; D006801:Humans; D051798:Inhibitor of Differentiation Protein 1; D008024:Ligands; D008156:Luciferases / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins; D020218:Response Elements; D012689:Sequence Homology, Nucleic Acid; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D001616:beta-Galactosidase / Q000378:metabolism
D019485:Bone Morphogenetic Proteins; D004268:DNA-Binding Proteins; C497453:ID1 protein, human; C497455:Idb1 protein, mouse; D051798:Inhibitor of Differentiation Protein 1; D008024:Ligands; D012097:Repressor Proteins; D014157:Transcription Factors; D008156:Luciferases; D001616:beta-Galactosidase