Requirements for transforming growth factor-beta regulation of the pro-alpha 2(I) collagen and plasminogen activator inhibitor-1 promoters.
Experiments were designed to clarify the role of several proteins, junB, retinoblastoma protein (RB), and the transforming growth factor-beta (TGF-beta) receptors that are potential intermediates in TGF-beta activation of the alpha 2(I) collagen promoter. Treatment of NIH-3T3 cells with TGF-beta increased the activity of a transiently transfected murine alpha 2(I) collagen promoter (nucleotides -350 to +54) fused to a luciferase reporter gene 9-fold. Cotransfection of a junB stimulated the basal activity of the alpha 2(I) collagen promoter 93-fold, respectively. Expression of antisense junB RNA attenuated the effect of TGF-beta. Simian virus 40 large T antigen, an inhibitor RB function, did not prevent TGF-beta effects on the alpha 2(I) collagen promoter. A chimeric receptor containing the extracellular domain of the colony-stimulating factor-1 receptor and the intracellular domain of the type I TGF-beta receptor enhanced alpha 2(I) collagen promoter activity 4.8-fold, whereas a similar chimera containing the type II receptor intracellular domain had much weaker effects. Similar results were obtained with a plasminogen activator inhibitor-1 promoter, previously shown to be activated by TGF-beta through AP-1 elements. We conclude that TGF-beta activates the alpha 2(I) collagen and plasminogen activator inhibitor-1 promoters in NIH-3T3 cells through junB and the type I TGF-beta receptor kinase domain.
Chang
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Department of Pediatrics, Hospital for Sick Children, University of Toronto, Canada.
Goldberg
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D016475:3T3 Cells; D000818:Animals; D005786:Gene Expression Regulation; D016762:Genes, fos; D016758:Genes, jun; D051379:Mice; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics*; D011347:Procollagen / Q000235:genetics*; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta; D016160:Retinoblastoma Protein / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000502:physiology*
D017395:Plasminogen Activator Inhibitor 1; D011347:Procollagen; D018125:Receptors, Transforming Growth Factor beta; D016160:Retinoblastoma Protein; D016212:Transforming Growth Factor beta; D020794:Receptor Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I