Journal of Biological Chemistry
Volume 277, Issue 5, 1 February 2002, Pages 3176-3185
Journal home page for Journal of Biological Chemistry

GENES: STRUCTURE AND REGULATION
Direct Binding of Smad1 and Smad4 to Two Distinct Motifs Mediates Bone Morphogenetic Protein-specific Transcriptional Activation ofId1 Gene*

https://doi.org/10.1074/jbc.M106826200Get rights and content
Under a Creative Commons license
open access

Bone morphogenetic proteins (BMPs) are potent inhibitors of myoblast differentiation and inducers of bone formation both in vivo and in vitro. Expression of Id1, a negative regulator of basic helix-loop-helix transcription factors, is up-regulated by BMPs and contributes to the antimyogenic effects of this family of cytokines. In this report, we have identified a specific BMP-2 immediate early response enhancer in the human Id1gene. Transcriptional activation of the enhancer was increased by overexpression of BMP-responsive Smads, and Smad4 and was completely abrogated in Smad4-deficient cells. Deletion analysis demonstrates that the responsive region is composed of two separate DNA binding elements, a set of overlapping GC boxes, which bind BMP-regulated Smads upon BMP stimulation, and three repeats of CAGAC boxes. Gel shift and oligonucleotide pull-down assays demonstrated that these two types of motifs were capable of binding their corresponding Smads. However, deletion or mutation of either DNA binding element was nonadditive, since disruption of either GC or CAGAC boxes resulted in complete or severe loss of BMP-2 responsiveness. These data suggest the simultaneous requirement of two independent DNA binding elements to allow functional cooperativity of BMP-regulated Smads and Smad4 in BMP-activated gene promoters.

Cited by (0)

Published, JBC Papers in Press, November 7, 2001, DOI 10.1074/jbc.M106826200

*

This work was supported by Ministerio de Educación y Ciencia Grant PM98–0183.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

§

Supported by a doctoral fellowship from the Ministerio de Educación y Ciencia (F.P.I.).

Supported by a doctoral fellowship from the Fundació Pi i Sunyer.