scholarly journals NEDD4-2 (neural precursor cell expressed, developmentally down-regulated 4-2) negatively regulates TGF-β (transforming growth factor-β) signalling by inducing ubiquitin-mediated degradation of Smad2 and TGF-β type I receptor

2005 ◽  
Vol 386 (3) ◽  
pp. 461-470 ◽  
Author(s):  
Go KURATOMI ◽  
Akiyoshi KOMURO ◽  
Kouichiro GOTO ◽  
Masahiko SHINOZAKI ◽  
Keiji MIYAZAWA ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Ubiquitin Ligases ◽  
Transforming Growth Factor Β ◽  
Precursor Cell ◽  
Neural Precursor ◽  
Type I ◽  
Dependent Manner ◽  
E3 Ubiquitin Ligases ◽  
Neural Precursor Cell

Inhibitory Smad, Smad7, is a potent inhibitor of TGF-β (transforming growth factor-β) superfamily signalling. By binding to activated type I receptors, it prevents the activation of R-Smads (receptor-regulated Smads). To identify new components of the Smad pathway, we performed yeast two-hybrid screening using Smad7 as bait, and identified NEDD4-2 (neural precursor cell expressed, developmentally down-regulated 4-2) as a direct binding partner of Smad7. NEDD4-2 is structurally similar to Smurfs (Smad ubiquitin regulatory factors) 1 and 2, which were identified previously as E3 ubiquitin ligases for R-Smads and TGF-β superfamily receptors. NEDD4-2 functions like Smurfs 1 and 2 in that it associates with TGF-β type I receptor via Smad7, and induces its ubiquitin-dependent degradation. Moreover, NEDD4-2 bound to TGF-β-specific R-Smads, Smads 2 and 3, in a ligand-dependent manner, and induced degradation of Smad2, but not Smad3. However, in contrast with Smurf2, NEDD4-2 failed to induce ubiquitination of SnoN (Ski-related novel protein N), although NEDD4-2 bound to SnoN via Smad2 more strongly than Smurf2. We showed further that overexpressed NEDD4-2 prevents transcriptional activity induced by TGF-β and BMP, whereas silencing of the NEDD4-2 gene by siRNA (small interfering RNA) resulted in enhancement of the responsiveness to TGF-β superfamily cytokines. These data suggest that NEDD4-2 is a member of the Smurf-like C2-WW-HECT (WW is Trp-Trp and HECT is homologous to the E6-accessory protein) type E3 ubiquitin ligases, which negatively regulate TGF-β superfamily signalling through similar, but not identical, mechanisms to those used by Smurfs.

scholarly journals Regulation of the transforming growth factor β pathway by reversible ubiquitylation

Open Biology ◽  
2012 ◽  
Vol 2 (5) ◽  
pp. 120082 ◽  
Author(s):  
Mazin A. Al-Salihi ◽  
Lina Herhaus ◽  
Gopal P. Sapkota
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Ubiquitin Ligases ◽  
Transforming Growth Factor Β ◽  
E3 Ubiquitin Ligases ◽  
Surface Receptors ◽  
Biochemical Processes ◽  
Regulatory Processes ◽  
Tgfβ Signalling

The transforming growth factor β (TGFβ) signalling pathway plays a central role during embryonic development and in adult tissue homeostasis. It regulates gene transcription through a signalling cascade from cell surface receptors to intracellular SMAD transcription factors and their nuclear cofactors. The extent, duration and potency of signalling in response to TGFβ cytokines are intricately regulated by complex biochemical processes. The corruption of these regulatory processes results in aberrant TGFβ signalling and leads to numerous human diseases, including cancer. Reversible ubiquitylation of pathway components is a key regulatory process that plays a critical role in ensuring a balanced response to TGFβ signals. Many studies have investigated the mechanisms by which various E3 ubiquitin ligases regulate the turnover and activity of TGFβ pathway components by ubiquitylation. Moreover, recent studies have shed new light into their regulation by deubiquitylating enzymes. In this report, we provide an overview of current understanding of the regulation of TGFβ signalling by E3 ubiquitin ligases and deubiquitylases.

scholarly journals Transforming Growth Factor-β Induces Nuclear Import of Smad3 in an Importin-β1 and Ran-dependent Manner

2001 ◽  
Vol 12 (4) ◽  
pp. 1079-1091 ◽  
Author(s):  
Akira Kurisaki ◽  
Shingo Kose ◽  
Yoshihiro Yoneda ◽  
Carl-Henrik Heldin ◽  
Aristidis Moustakas
Keyword(s):  
Growth Factor ◽  
Nuclear Import ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Structural Basis ◽  
Type I ◽  
Dependent Manner ◽  
Permeabilized Cells ◽  
Terminal Domain

Smad proteins are cytoplasmic signaling effectors of transforming growth factor-β (TGF-β) family cytokines and regulate gene transcription in the nucleus. Receptor-activated Smads (R-Smads) become phosphorylated by the TGF-β type I receptor. Rapid and precise transport of R-Smads to the nucleus is of crucial importance for signal transduction. By focusing on the R-Smad Smad3 we demonstrate that 1) only activated Smad3 efficiently enters the nucleus of permeabilized cells in an energy- and cytosol-dependent manner. 2) Smad3, via its N-terminal domain, interacts specifically with importin-β1 and only after activation by receptor. In contrast, the unique insert of exon3 in the N-terminal domain of Smad2 prevents its association with importin-β1. 3) Nuclear import of Smad3 in vivo requires the action of the Ran GTPase, which mediates release of Smad3 from the complex with importin-β1. 4) Importin-β1, Ran, and p10/NTF2 are sufficient to mediate import of activated Smad3. The data describe a pathway whereby Smad3 phosphorylation by the TGF-β receptor leads to enhanced interaction with importin-β1 and Ran-dependent import and release into the nucleus. The import mechanism of Smad3 shows distinct features from that of the related Smad2 and the structural basis for this difference maps to the divergent sequences of their N-terminal domains.

scholarly journals Transforming Growth Factor β Facilitates β-TrCP-Mediated Degradation of Cdc25A in a Smad3-Dependent Manner

2005 ◽  
Vol 25 (8) ◽  
pp. 3338-3347 ◽  
Author(s):  
Dipankar Ray ◽  
Yasuhisa Terao ◽  
Dipali Nimbalkar ◽  
Li-Hao Chu ◽  
Maddalena Donzelli ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Dependent Manner ◽  
Anaphase Promoting Complex ◽  
Mutant Proteins ◽  
Major Mechanism ◽  
Β Receptor ◽  
Interfering Rna

ABSTRACT Ubiquitin-dependent degradation of Cdc25A is a major mechanism for damage-induced S-phase checkpoint. Two ubiquitin ligases, the Skp1-cullin-β-TrCP (SCFβ-TrCP) complex and the anaphase-promoting complex (APCCdh1), are involved in Cdc25A degradation. Here we demonstrate that the transforming growth factor β (TGF-β)-Smad3 pathway promotes SCFβ-TrCP-mediated Cdc25A ubiquitination. Cells treated with TGF-β, as well as cells transfected with Smad3 or a constitutively active type I TGF-β receptor, exhibit increased ubiquitination and markedly shortened half-lives of Cdc25A. Furthermore, Cdc25A is stabilized in cells transfected with Smad3 small interfering RNA (siRNA) and cells from Smad3-null mice. TGF-β-induced ubiquitination is associated with Cdc25A phosphorylation at the β-TrCP docking site (DS82G motif) and physical association of Cdc25A with Smad3 and β-TrCP. Cdc25A mutant proteins deficient in DS82G phosphorylation are resistant to TGF-β-Smad3-induced degradation, whereas a Cdc25A mutant protein defective in APCCdh1 recognition undergoes efficient degradation. Smad3 siRNA inhibits β-TrCP-Cdc25A interaction and Cdc25A degradation in response to TGF-β. β-TrCP2 siRNA also inhibits Smad3-induced Cdc25A degradation. In contrast, Cdh1 siRNA had no effect on Cdc25A down-regulation by Smad3. These data suggest that Smad3 plays a key role in the regulation of Cdc25A ubiquitination by SCFβ-TrCP and that Cdc25A stabilization observed in various cancers could be associated with defects in the TGF-β-Smad3 pathway.

scholarly journals FKBP12 functions as an adaptor of the Smad7–Smurf1 complex on activin type I receptor

2006 ◽  
Vol 36 (3) ◽  
pp. 569-579 ◽  
Author(s):  
T Yamaguchi ◽  
A Kurisaki ◽  
N Yamakawa ◽  
K Minakuchi ◽  
H Sugino
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Dependent Manner ◽  
Regulatory Factor ◽  
Fk506 Binding Protein ◽  
Adaptor Molecule ◽  
Inhibitory Function ◽  
Inhibitory Molecule

The cytoplasmic immunophilin FKBP12, a 12 kDa FK506-binding protein, has been shown to act as an inhibitor for transforming growth factor-β (TGF-β) signaling. FKBP12 binds to the glycine- and serine-rich motif (GS motif) of the TGF-β type I receptor, and functions as a secure switch to prevent the leaky signal. Upon stimulation with ligand, FKBP12 is released from the receptor to fully propagate the signal. We found that activin, a member of TGF-β superfamily, also induced the dissociation of FKBP12 from the activin type I receptor (ALK4). However, we observed that the released FKBP12 associates again with the receptor a few hours later. FKBP12 also interacted with another inhibitory molecule of activin signal, Smad7, in an activin-dependent manner, and formed a complex with Smad7 on the type I receptor. FK506, a chemical ligand for FKBP12, which dissociates FKBP12 from the receptor, decreased the interaction between Smad7 and Smad ubiquitin regulatory factor 1 (Smurf1). FK506 also inhibited the ubiquitination of the type I receptor by Smurf1. These findings indicate a new inhibitory function of FKBP12 as an adaptor molecule for the Smad7–Smurf1 complex to regulate the duration of the activin signal.

Intracisternal administration of transforming growth factor-β evokes fever through the induction of cyclooxygenase-2 in brain endothelial cells

2008 ◽  
Vol 294 (1) ◽  
pp. R266-R275 ◽  
Author(s):  
Shigenobu Matsumura ◽  
Tetsuro Shibakusa ◽  
Teppei Fujikawa ◽  
Hiroyuki Yamada ◽  
Kiyoshi Matsumura ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Proinflammatory Cytokines ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cyclooxygenase 2 ◽  
Dependent Manner ◽  
Cox 2 ◽  
Β Receptor

Transforming growth factor-β (TGF-β), a pleiotropic cytokine, regulates cell proliferation, differentiation, and apoptosis, and plays a key role in development and tissue homeostasis. TGF-β functions as an anti-inflammatory cytokine because it suppresses microglia and B-lymphocyte functions, as well as the production of proinflammatory cytokines. However, we previously demonstrated that the intracisternal administration of TGF-β induces fever like that produced by proinflammatory cytokines. In this study, we investigated the mechanism of TGF-β-induced fever. The intracisternal administration of TGF-β increased body temperature in a dose-dependent manner. Pretreatment with cyclooxygenase-2 (COX-2)-selective inhibitor significantly suppressed TGF-β-induced fever. COX-2 is known as one of the rate-limiting enzymes of the PGE2 synthesis pathway, suggesting that fever induced by TGF-β is COX-2 and PGE2 dependent. TGF-β increased PGE2 levels in cerebrospinal fluid and increased the expression of COX-2 in the brain. Double immunostaining of COX-2 and von Willebrand factor (vWF, an endothelial cell marker) revealed that COX-2-expressing cells were mainly endothelial cells. Although not all COX-2-immunoreactive cells express TGF-β receptor, some COX-2-immunoreactive cells express activin receptor-like kinase-1 (ALK-1, an endothelial cell-specific TGF-β receptor), suggesting that TGF-β directly or indirectly acts on endothelial cells to induce COX-2 expression. These findings suggest a novel function of TGF-β as a proinflammatory cytokine in the central nervous system.

scholarly journals Apurinic/apyrimidinic endonuclease 1 regulates angiogenesis in a transforming growth factor β‐dependent manner in human osteosarcoma

2015 ◽  
Vol 106 (10) ◽  
pp. 1394-1401 ◽  
Author(s):  
Xuan Jiang ◽  
Jinlu Shan ◽  
Nan Dai ◽  
Zhaoyang Zhong ◽  
Yi Qing ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Dependent Manner ◽  
Human Osteosarcoma
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