Mechanisms of bone morphogenetic protein 2 (BMP2) stimulated inhibitor of DNA binding 3 (Id3) transcription.
Bone morphogenetic protein 2 (BMP2) stimulates expression of the inhibitors of DNA binding (Id) 1, 2, and 3 in a variety of cell types. Here, we examined mechanisms mediating BMP2-stimulated Id3 transcription in murine gonadotropes. Using a combination of quantitative RT-PCR, promoter-reporter analyses, over-expression, and RNA interference approaches, we demonstrate that BMP2 signals via the BMPR2 and BMPR1A (ALK3) receptors and intracellular signaling proteins SMADs 1 and 5 to stimulate Id3 transcription. We further define a novel 6-bp cis-element mediating BMP2- and SMAD-dependent transcription, though this site does not appear to bind SMADs directly. A specific DNA binding protein complex binds to this element, but its constituent protein(s) remain undetermined. Recently, a more distal enhancer was shown to mediate BMP4-induction of the human ID3 gene in ovarian cancer cells. This enhancer is conserved in the murine gene and we demonstrate its role in BMP2-induced Id3 promoter activity in gonadotropes. Conversely, the proximal cis-element defined here is also conserved in human ID3 and we demonstrate its functional role in BMP2-induction of ID3 transcription. Finally, we show that the two regulatory elements also mediate BMP2-induction of Id3 promoter activity in murine fibroblasts. Collectively, we have defined a general mechanism whereby BMP2 regulates Id3/ID3 transcription in different cell types and in different species.
Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6.
Catherine C
CC
Ho
Xiang
X
Zhou
Yuji
Y
Mishina
Daniel J
DJ
Bernard
D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D052005:Bone Morphogenetic Protein Receptors, Type I / Q000235:genetics / Q000378:metabolism; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D006801:Humans; D051797:Inhibitor of Differentiation Protein 2 / Q000235:genetics / Q000378:metabolism; D051796:Inhibitor of Differentiation Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D051898:Smad1 Protein / Q000378:metabolism; D051902:Smad5 Protein / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*
D055396:Bone Morphogenetic Protein 2; C497450:ID2 protein, human; C497452:Idb2 protein, mouse; D051797:Inhibitor of Differentiation Protein 2; D051796:Inhibitor of Differentiation Proteins; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D051898:Smad1 Protein; D051902:Smad5 Protein; C067679:Idb3 protein, mouse; C075640:ID3 protein, human; D052005:Bone Morphogenetic Protein Receptors, Type I