scholarly journals Latent Transforming Growth Factor-β Binding Protein Domains Involved in Activation and Transglutaminase-dependent Cross-Linking of Latent Transforming Growth Factor-β

1997 ◽  
Vol 136 (5) ◽  
pp. 1151-1163 ◽  
Author(s):  
Irene Nunes ◽  
Pierre-Emmanuel Gleizes ◽  
Christine N. Metz ◽  
Daniel B Rifkin
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Noncovalent Interactions ◽  
Binding Protein ◽  
Transforming Growth Factor Β ◽  
Cell Types ◽  
Terminal Region ◽  
Cross Linking ◽  
Surface Receptors ◽  
Amino Terminal

Transforming growth factor-β (TGF-β) is secreted by many cell types as part of a large latent complex composed of three subunits: TGF-β, the TGF-β propeptide, and the latent TGF-β binding protein (LTBP). To interact with its cell surface receptors, TGF-β must be released from the latent complex by disrupting noncovalent interactions between mature TGF-β and its propeptide. Previously, we identified LTBP-1 and transglutaminase, a cross-linking enzyme, as reactants involved in the formation of TGF-β. In this study, we demonstrate that LTBP-1 and large latent complex are substrates for transglutaminase. Furthermore, we show that the covalent association between LTBP-1 and the extracellular matrix is transglutaminase dependent, as little LTBP-1 is recovered from matrix digests prepared from cultures treated with transglutaminase inhibitors. Three polyclonal antisera to glutathione S–transferase fusion proteins containing amino, middle, or carboxyl regions of LTBP-1S were used to identify domains of LTBP-1 involved in crosslinking and formation of TGF-β by transglutaminase. Antibodies to the amino and carboxyl regions of LTBP-1S abrogate TGF-β generation by vascular cell cocultures or macrophages. However, only antibodies to the amino-terminal region of LTBP-1 block transglutaminase-dependent cross-linking of large latent complex or LTBP-1. To further identify transglutaminase-reactive domains within the amino-terminal region of LTBP-1S, mutants of LTBP-1S with deletions of either the amino-terminal 293 (ΔN293) or 441 (ΔN441) amino acids were expressed transiently in CHO cells. Analysis of the LTBP-1S content in matrices of transfected CHO cultures revealed that ΔN293 LTBP-1S was matrix associated via a transglutaminasedependent reaction, whereas ΔN441 LTBP-1S was not. This suggests that residues 294–441 are critical to the transglutaminase reactivity of LTBP-1S.

scholarly journals CREB binding protein is a required coactivator for Smad-dependent, transforming growth factor β transcriptional responses in endothelial cells

1998 ◽  
Vol 95 (16) ◽  
pp. 9506-9511 ◽  
Author(s):  
James N. Topper ◽  
Maria R. DiChiara ◽  
Jonathan D. Brown ◽  
Amy J. Williams ◽  
Dean Falb ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Binding Protein ◽  
Transforming Growth Factor Β ◽  
Cell Types ◽  
Creb Binding Protein ◽  
Transcriptional Responses ◽  
Smad Proteins ◽  
Smad Protein

The transforming growth factor-β (TGF-β) superfamily of growth factors and cytokines has been implicated in a variety of physiological and developmental processes within the cardiovascular system. Smad proteins are a recently described family of intracellular signaling proteins that transduce signals in response to TGF-β superfamily ligands. We demonstrate by both a mammalian two-hybrid and a biochemical approach that human Smad2 and Smad4, two essential Smad proteins involved in mediating TGF-β transcriptional responses in endothelial and other cell types, can functionally interact with the transcriptional coactivator CREB binding protein (CBP). This interaction is specific in that it requires ligand (TGF-β) activation and is mediated by the transcriptional activation domains of the Smad proteins. A closely related, but distinct endothelial-expressed Smad protein, Smad7, which does not activate transcription in endothelial cells, does not interact with CBP. Furthermore, Smad2,4–CBP interactions involve the COOH terminus of CBP, a region that interacts with other regulated transcription factors such as certain signal transduction and transcription proteins and nuclear receptors. Smad–CBP interactions are required for Smad-dependent TGF-β-induced transcriptional responses in endothelial cells, as evidenced by inhibition with overexpressed 12S E1A protein and reversal of this inhibition with exogenous CBP. This report demonstrates a functional interaction between Smad proteins and an essential component of the mammalian transcriptional apparatus (CBP) and extends our insight into how Smad proteins may regulate transcriptional responses in many cell types. Thus, functional Smad–coactivator interactions may be an important locus of signal integration in endothelial cells.

scholarly journals The Latent Transforming Growth Factor-β–binding Protein-1 Promotes In Vitro Differentiation of Embryonic Stem Cells into Endothelium

2000 ◽  
Vol 11 (12) ◽  
pp. 4295-4308 ◽  
Author(s):  
Anna Gualandris ◽  
Justin P. Annes ◽  
Marco Arese ◽  
Irene Noguera ◽  
Vladimir Jurukovski ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Binding Protein ◽  
Es Cells ◽  
Embryonic Stem ◽  
Transforming Growth Factor Β ◽  
Cell Types ◽  
Embryoid Bodies

The latent transforming growth factor-β–binding protein-1 (LTBP-1) belongs to a family of extracellular glycoproteins that includes three additional isoforms (LTBP-2, -3, and -4) and the matrix proteins fibrillin-1 and -2. Originally described as a TGF-β–masking protein, LTBP-1 is involved both in the sequestration of latent TGF-β in the extracellular matrix and the regulation of its activation in the extracellular environment. Whereas the expression of LTBP-1 has been analyzed in normal and malignant cells and rodent and human tissues, little is known about LTBP-1 in embryonic development. To address this question, we used murine embryonic stem (ES) cells to analyze the appearance and role of LTBP-1 during ES cell differentiation. In vitro, ES cells aggregate to form embryoid bodies (EBs), which differentiate into multiple cell lineages. We analyzed LTBP-1 gene expression and LTBP-1 fiber appearance with respect to the emergence and distribution of cell types in differentiating EBs. LTBP-1 expression increased during the first 12 d in culture, appeared to remain constant between d 12 and 24, and declined thereafter. By immunostaining, fibrillar LTBP-1 was observed in those regions of the culture containing endothelial, smooth muscle, and epithelial cells. We found that inclusion of a polyclonal antibody to LTBP-1 during EB differentiation suppressed the expression of the endothelial specific genes ICAM-2 and von Willebrand factor and delayed the organization of differentiated endothelial cells into cord-like structures within the growing EBs. The same effect was observed when cultures were treated with either antibodies to TGF-β or the latency associated peptide, which neutralize TGF-β. Conversely, the organization of endothelial cells was enhanced by incubation with TGF-β1. These results suggest that during differentiation of ES cells LTBP-1 facilitates endothelial cell organization via a TGF-β–dependent mechanism.

Versican G1 and G3 domains are upregulated and latent transforming growth factor-β binding protein-4 is downregulated in breast cancer stroma

Breast Cancer ◽  
2011 ◽  
Vol 19 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Yuko Takahashi ◽  
Hiroko Kuwabara ◽  
Masahiko Yoneda ◽  
Zenzo Isogai ◽  
Nobuhiko Tanigawa ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Binding Protein ◽  
Transforming Growth Factor Β ◽  
Cancer Stroma

scholarly journals Extracellular Matrix and Cytokines: A Functional Unit

2000 ◽  
Vol 7 (2-4) ◽  
pp. 89-101 ◽  
Author(s):  
Elke Schönherr ◽  
Heinz-JüRgen Hausser
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Heparan Sulfate ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Heparin Binding ◽  
Cytokine Network ◽  
Surface Receptors ◽  
Core Proteins ◽  
The Matrix

The extracellular matrix (ECM) as well as soluble mediators like cytokines can influence the behavior of cells in very distinct as well as cooperative ways. One group of ECM molecules which shows an especially broad cooperativety with cytokines and growth factors are the proteoglycans. Proteoglycans can interact with their core proteins as well as their glycosaminoglycan chains with cytokines. These interactions can modify the binding of cytokines to their cell surface receptors or they can lead to the storage of the soluble factors in the matrix. Proteoglycans themselves may even have cytokine activity. In this review we describe different proteoglycans and their interactions and relationships with cytokines and we discuss in more detail the extracellular regulation of the activity of transforming growth factor-β (TGF-β) by proteoglycans and other ECM molecules. In the third part the interaction of heparan sulfate chains with fibroblast growth factor-2 (FGF-2, basic FGF) as a prototype example for the interaction of heparin-binding cytokines with heparan sulfate proteoglycans is presented to illustrate the different levels of mutual dependence of the cytokine network and the ECM.

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.

Latent transforming growth factor-β binding protein-1 LTBP1

1998 ◽  
pp. 178-180
Author(s):  
Shirley Ayad ◽  
Ray Boot-Handford ◽  
Martin J. Humphries ◽  
Karl E. Kadler ◽  
Adrian Shuttleworth
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Binding Protein ◽  
Transforming Growth Factor Β
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