scholarly journals Characterization of a Bone Morphogenetic Protein-responsive Smad-binding Element

2000 ◽  
Vol 11 (2) ◽  
pp. 555-565 ◽  
Author(s):  
Kiyoshi Kusanagi ◽  
Hirofumi Inoue ◽  
Yasuhiro Ishidou ◽  
Hiromu K. Mishima ◽  
Masahiro Kawabata ◽  
...  
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Transforming Growth Factor ◽  
Specific Interaction ◽  
Transforming Growth Factor Β ◽  
Serine Threonine Kinase ◽  
Bmp Receptors ◽  
Morphogenetic Protein ◽  
Smad Phosphorylation ◽  
Smad Proteins ◽  
Smad Binding Element

Bone morphogenetic proteins (BMPs) are pleiotropic growth and differentiation factors belonging to the transforming growth factor-β (TGF-β) superfamily. Signals of the TGF-β-like ligands are propagated to the nucleus through specific interaction of transmembrane serine/threonine kinase receptors and Smad proteins. GCCGnCGC has been suggested as a consensus binding sequence for DrosophilaMad regulated by a BMP-like ligand, Decapentaplegic. Smad1 is one of the mammalian Smads activated by BMPs. Here we show that Smad1 binds to this motif upon BMP stimulation in the presence of the common Smad, Smad4. The binding affinity is likely to be relatively low, because Smad1 binds to three copies of the motif weakly, but more repeats of the motif significantly enhance the binding. Heterologous reporter genes (GCCG-Lux) with multiple repeats of the motif respond to BMP stimulation but not to TGF-β or activin. Mutational analyses reveal several bases critical for the responsiveness. A natural BMP-responsive reporter, pTlx-Lux, is activated by BMP receptors in P19 cells but not in mink lung cells. In contrast, GCCG-Lux responds to BMP stimulation in both cells, suggesting that it is a universal reporter that directly detects Smad phosphorylation by BMP receptors.

scholarly journals Bone Morphogenetic Protein Receptor Complexes on the Surface of Live Cells: A New Oligomerization Mode for Serine/Threonine Kinase Receptors

2000 ◽  
Vol 11 (3) ◽  
pp. 1023-1035 ◽  
Author(s):  
Lilach Gilboa ◽  
Anja Nohe ◽  
Tanja Geissendörfer ◽  
Walter Sebald ◽  
Yoav I. Henis ◽  
...  
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Live Cells ◽  
Type I ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Receptor Complexes ◽  
Bmp Receptors ◽  
Protein Receptor

The bone morphogenetic proteins (BMPs) play important roles in embryogenesis and normal cell growth. The BMP receptors belong to the family of serine/threonine kinase receptors, whose activation has been investigated intensively for the transforming growth factor-β (TGF-β) receptor subfamily. However, the interactions between the BMP receptors, the composition of the active receptor complex, and the role of the ligand in its formation have not yet been investigated and were usually assumed to follow the same pattern as the TGF-β receptors. Here we demonstrate that the oligomerization pattern of the BMP receptors is different and is more flexible and susceptible to modulation by ligand. Using several complementary approaches, we investigated the formation of homomeric and heteromeric complexes between the two known BMP type I receptors (BR-Ia and BR-Ib) and the BMP type II receptor (BR-II). Coimmunoprecipitation studies detected the formation of heteromeric and homomeric complexes among all the BMP receptor types even in the absence of ligand. These complexes were also detected at the cell surface after BMP-2 binding and cross-linking. Using antibody-mediated immunofluorescence copatching of epitope-tagged receptors, we provide evidence in live cells for preexisting heteromeric (BR-II/BR-Ia and BR-II/BR-Ib) and homomeric (BR-II/BR-II, BR-Ia/ BR-Ia, BR-Ib/ BR-Ib, and also BR-Ia/ BR-Ib) oligomers in the absence of ligand. BMP-2 binding significantly increased hetero- and homo-oligomerization (except for the BR-II homo-oligomer, which binds ligand poorly in the absence of BR-I). In contrast to previous observations on TGF-β receptors, which were found to be fully homodimeric in the absence of ligand, the BMP receptors show a much more flexible oligomerization pattern. This novel feature in the oligomerization mode of the BMP receptors allows higher variety and flexibility in their responses to various ligands as compared with the TGF-β receptors.

scholarly journals Eps15R is required for bone morphogenetic protein signalling and differentially compartmentalizes with Smad proteins

Open Biology ◽  
2012 ◽  
Vol 2 (4) ◽  
pp. 120060 ◽  
Author(s):  
Elizabeth M. Callery ◽  
Chong Yon Park ◽  
Xin Xu ◽  
Haitao Zhu ◽  
James C. Smith ◽  
...  
Keyword(s):  
Growth Factor ◽  
Bone Morphogenetic Proteins ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Adaptor Protein ◽  
Transforming Growth Factor Β ◽  
Morphogenetic Protein ◽  
Smad Proteins ◽  
Epidermal Growth ◽  
Bmp Signalling

Transforming growth factor β superfamily members signal through Smad transcription factors. Bone morphogenetic proteins (BMPs) act via Smads 1, 5 and 8 and TGF-βs signal through Smads 2 and 3. The endocytic adaptor protein Eps15R, or ‘epidermal growth factor (EGF) receptor pathway substrate 15-related protein’ is a component of EGF signal transduction, mediating internalization of the EGF receptor. We show that it interacts with Smad proteins, is required for BMP signalling in animal caps and stimulates Smad1 transcriptional activity. This function resides in the Asp-Pro-Phe motif-enriched ‘DPF domain’ of Eps15R, which activates transcription and antagonizes Smad2 signalling. In living cells, Eps15R segregates into spatially distinct regions with different Smads, indicating an unrecognized level of Smad compartmentalization.

scholarly journals Transforming Growth Factor β-Mediated Transcriptional Repression of c-myc Is Dependent on Direct Binding of Smad3 to a Novel Repressive Smad Binding Element

2004 ◽  
Vol 24 (6) ◽  
pp. 2546-2559 ◽  
Author(s):  
Joshua P. Frederick ◽  
Nicole T. Liberati ◽  
David S. Waddell ◽  
Yigong Shi ◽  
Xiao-Fan Wang
Keyword(s):  
Growth Factor ◽  
Transcriptional Repression ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cell Types ◽  
Specific Cell ◽  
Smad Proteins ◽  
Smad Binding Element

ABSTRACT Smad proteins are the most well-characterized intracellular effectors of the transforming growth factor β (TGF-β) signal. The ability of the Smads to act as transcriptional activators via TGF-β-induced recruitment to Smad binding elements (SBE) within the promoters of TGF-β target genes has been firmly established. However, the elucidation of the molecular mechanisms involved in TGF-β-mediated transcriptional repression are only recently being uncovered. The proto-oncogene c-myc is repressed by TGF-β, and this repression is required for the manifestation of the TGF-β cytostatic program in specific cell types. We have shown that Smad3 is required for both TGF-β-induced repression of c-myc and subsequent growth arrest in keratinocytes. The transcriptional repression of c-myc is dependent on direct Smad3 binding to a novel Smad binding site, termed a repressive Smad binding element (RSBE), within the TGF-β inhibitory element (TIE) of the c-myc promoter. The c-myc TIE is a composite element, comprised of an overlapping RSBE and a consensus E2F site, that is capable of binding at least Smad3, Smad4, E2F-4, and p107. The RSBE is distinct from the previously defined SBE and may partially dictate, in conjunction with the promoter context of the overlapping E2F site, whether the Smad3-containing complex actively represses, as opposed to transactivates, the c-myc promoter.

Bone Morphogenetic Proteins and Their Receptors in the Eye

2007 ◽  
Vol 232 (8) ◽  
pp. 979-992 ◽  
Author(s):  
Robert J. Wordinger ◽  
Abbot F. Clark
Keyword(s):  
Growth Factor ◽  
Bone Morphogenetic Proteins ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Bmp Signaling ◽  
Receptor Expression ◽  
Future Research ◽  
Cellular Functions ◽  
Ocular Tissues ◽  
Bmp Receptors

The human genome encodes at least 42 different members of the transforming growth factor-β superfamily of growth factors. Bone morphogenetic proteins (BMPs) are the largest subfamily of proteins within the transforming growth factor-β superfamily and are involved in numerous cellular functions including development, morphogenesis, cell proliferation, apoptosis, and extracellular matrix synthesis. This article first reviews BMPs and BMP receptors, BMP signaling pathways, and mechanisms controlling BMP signaling. Second, we review BMP and BMP receptor expression during embryonic ocular development/ differentiation and in adult ocular tissues. Lastly, future research directions with respect to BMP, BMP receptors, and ocular tissues are suggested.

scholarly journals Cooperative Inhibition of Bone Morphogenetic Protein Signaling by Smurf1 and Inhibitory Smads

2003 ◽  
Vol 14 (7) ◽  
pp. 2809-2817 ◽  
Author(s):  
Gyo Murakami ◽  
Tetsuro Watabe ◽  
Kunio Takaoka ◽  
Kohei Miyazono ◽  
Takeshi Imamura
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Mammalian Cells ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Bmp Signaling ◽  
Type I ◽  
Protein Signaling ◽  
Reporter Construct ◽  
Bone Morphogenetic Protein Signaling ◽  
Morphogenetic Protein

Smad ubiquitin regulatory factor (Smurf) 1 binds to receptor-regulated Smads for bone morphogenetic proteins (BMPs) Smad1/5 and promotes their degradation. In addition, Smurf1 associates with transforming growth factor-β type I receptor through the inhibitory Smad (I-Smad) Smad7 and induces their degradation. Herein, we examined whether Smurf1 negatively regulates BMP signaling together with the I-Smads Smad6/7. Smurf1 and Smad6 cooperatively induced secondary axes in Xenopus embryos. Using a BMP-responsive promoter-reporter construct in mammalian cells, we found that Smurf1 cooperated with I-Smad in inhibiting BMP signaling and that the inhibitory activity of Smurf1 was not necessarily correlated with its ability to bind to Smad1/5 directly. Smurf1 bound to BMP type I receptors via I-Smads and induced ubiquitination and degradation of these receptors. Moreover, Smurf1 associated with Smad1/5 indirectly through I-Smads and induced their ubiquitination and degradation. Smurf1 thus controls BMP signaling with and without I-Smads through multiple mechanisms.

scholarly journals Id2 and Id3 Define the Potency of Cell Proliferation and Differentiation Responses to Transforming Growth Factor β and Bone Morphogenetic Protein

2004 ◽  
Vol 24 (10) ◽  
pp. 4241-4254 ◽  
Author(s):  
Marcin Kowanetz ◽  
Ulrich Valcourt ◽  
Rosita Bergström ◽  
Carl-Henrik Heldin ◽  
Aristidis Moustakas
Keyword(s):  
Epithelial Cells ◽  
Growth Inhibition ◽  
Cell Fate ◽  
Bone Morphogenetic Proteins ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Transforming Growth Factor Β ◽  
Mesenchymal Transition ◽  
Cell Proliferation And Differentiation ◽  
Morphogenetic Protein

ABSTRACT Transforming growth factors β (TGF-βs) inhibit growth of epithelial cells and induce differentiation changes, such as epithelial-mesenchymal transition (EMT). On the other hand, bone morphogenetic proteins (BMPs) weakly affect epithelial cell growth and do not induce EMT. Smad4 transmits signals from both TGF-β and BMP pathways. Stimulation of Smad4-deficient epithelial cells with TGF-β1 or BMP-7 in the absence or presence of exogenous Smad4, followed by cDNA microarray analysis, revealed 173 mostly Smad4-dependent, TGF-β-, or BMP-responsive genes. Among 25 genes coregulated by both factors, inhibitors of differentiation Id2 and Id3 showed long-term repression by TGF-β and sustained induction by BMP. The opposing regulation of Id genes is critical for proliferative and differentiation responses. Hence, ectopic Id2 or Id3 expression renders epithelial cells refractory to growth inhibition and EMT induced by TGF-β, phenocopying the BMP response. Knockdown of endogenous Id2 or Id3 sensitizes epithelial cells to BMP, leading to robust growth inhibition and induction of transdifferentiation. Thus, Id genes sense Smad signals and create a permissive or refractory nuclear environment that defines decisions of cell fate and proliferation.

scholarly journals Protective Effect and Mechanism of Bone Morphogenetic Protein-4 on Apoptosis of Human Lens Epithelium Cells under Oxidative Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bei Du ◽  
Jia-Lin Zheng ◽  
Liang-Yu Huang ◽  
Hong Zhang ◽  
Qiong Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Bone Morphogenetic Proteins ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Human Lens ◽  
Ocular Tissues ◽  
Targeted Deletion ◽  
Morphogenetic Protein ◽  
Activating Transcription Factor ◽  
Human Lens Epithelium

Bone morphogenetic proteins (BMPs), a member of the transforming growth factor β (TGF-β) superfamily, are abundant in human ocular tissues and play an important role in lens development. Targeted deletion of BMP-4 in mice results in failure of lens placode formation. Following lens maturation, the formation of senile cataracts is demonstrably associated with free radical-related oxidative stress. Previous studies reported that BMPs play an antiapoptotic role in cells under oxidative stress, and the BMP-4 signal is important in inflammation regulation and homeostasis. BMP-4 evidently suppressed the apoptosis of human lens epithelial cells (HLECS) under oxidative stress induced by H2O2. This protective antiapoptotic effect is partly due to a decrease in caspase-3 activity and reactive oxygen species (ROS) level. Furthermore, the expression of activating transcription factor- (ATF-) 6 and Krüppel-like factor- (KLF-) 6 increased under oxidative stress and decreased after BMP-4 treatment.

scholarly journals Msk is required for nuclear import of TGF-β/BMP-activated Smads

2007 ◽  
Vol 178 (6) ◽  
pp. 981-994 ◽  
Author(s):  
Lan Xu ◽  
Xiaohao Yao ◽  
Xiaochu Chen ◽  
Peiyuan Lu ◽  
Biliang Zhang ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Bone Morphogenetic Proteins ◽  
Nuclear Import ◽  
Transforming Growth Factor ◽  
Nuclear Translocation ◽  
Transforming Growth Factor Β ◽  
Nuclear Accumulation ◽  
Smad Proteins ◽  
Evolutionarily Conserved ◽  
Drosophila Cells

Nuclear translocation of Smad proteins is a critical step in signal transduction of transforming growth factor β (TGF-β) and bone morphogenetic proteins (BMPs). Using nuclear accumulation of the Drosophila Smad Mothers against Decapentaplegic (Mad) as the readout, we carried out a whole-genome RNAi screening in Drosophila cells. The screen identified moleskin (msk) as important for the nuclear import of phosphorylated Mad. Genetic evidence in the developing eye imaginal discs also demonstrates the critical functions of msk in regulating phospho-Mad. Moreover, knockdown of importin 7 and 8 (Imp7 and 8), the mammalian orthologues of Msk, markedly impaired nuclear accumulation of Smad1 in response to BMP2 and of Smad2/3 in response to TGF-β. Biochemical studies further suggest that Smads are novel nuclear import substrates of Imp7 and 8. We have thus identified new evolutionarily conserved proteins that are important in the signal transduction of TGF-β and BMP into the nucleus.

Bone morphogenetic protein and growth differentiation factor cytokine families and their protein antagonists

2010 ◽  
Vol 429 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Christopher C. Rider ◽  
Barbara Mulloy
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Transforming Growth Factor ◽  
Heparan Sulphate ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Single Family ◽  
Morphogenetic Protein ◽  
Wide Range ◽  
Receptor Dimers ◽  
Bmp Antagonist

The BMPs (bone morphogenetic proteins) and the GDFs (growth and differentiation factors) together form a single family of cystine-knot cytokines, sharing the characteristic fold of the TGFβ (transforming growth factor-β) superfamily. Besides the ability to induce bone formation, which gave the BMPs their name, the BMP/GDFs display morphogenetic activities in the development of a wide range of tissues. BMP/GDF homo- and hetero-dimers interact with combinations of type I and type II receptor dimers to produce multiple possible signalling complexes, leading to the activation of one of two competing sets of SMAD transcription factors. BMP/GDFs have highly specific and localized functions. These are regulated in a number of ways, including the developmental restriction of BMP/GDF expression and through the secretion of several specific BMP antagonist proteins that bind with high affinity to the cytokines. Curiously, a number of these antagonists are also members of the TGF-β superfamily. Finally a number of both the BMP/GDFs and their antagonists interact with the heparan sulphate side chains of cell-surface and extracellular-matrix proteoglycans.

Sign in / Sign up

Export Citation Format

Share Document