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Title: Force interacts with macromolecular structure in activation of TGF-β

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
National Institutes of Health (NIH)
OSTI Identifier:
1357645
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nature (London); Journal Volume: 542; Journal Issue: 7639
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Dong, Xianchi, Zhao, Bo, Iacob, Roxana E., Zhu, Jianghai, Koksal, Adem C., Lu, Chafen, Engen, John R., and Springer, Timothy A. Force interacts with macromolecular structure in activation of TGF-β. United States: N. p., 2017. Web. doi:10.1038/nature21035.
Dong, Xianchi, Zhao, Bo, Iacob, Roxana E., Zhu, Jianghai, Koksal, Adem C., Lu, Chafen, Engen, John R., & Springer, Timothy A. Force interacts with macromolecular structure in activation of TGF-β. United States. doi:10.1038/nature21035.
Dong, Xianchi, Zhao, Bo, Iacob, Roxana E., Zhu, Jianghai, Koksal, Adem C., Lu, Chafen, Engen, John R., and Springer, Timothy A. Wed . "Force interacts with macromolecular structure in activation of TGF-β". United States. doi:10.1038/nature21035.
@article{osti_1357645,
title = {Force interacts with macromolecular structure in activation of TGF-β},
author = {Dong, Xianchi and Zhao, Bo and Iacob, Roxana E. and Zhu, Jianghai and Koksal, Adem C. and Lu, Chafen and Engen, John R. and Springer, Timothy A.},
abstractNote = {},
doi = {10.1038/nature21035},
journal = {Nature (London)},
number = 7639,
volume = 542,
place = {United States},
year = {Wed Jan 25 00:00:00 EST 2017},
month = {Wed Jan 25 00:00:00 EST 2017}
}
  • Heat-shock cognate protein 70 (Hsc70), a molecular chaperone constitutively expressed in the cell, is involved in the regulation of several cellular signaling pathways. In this study, we found that TGF-β-induced phosphorylation and nuclear translocation of Smad2/3 were suppressed in fibroblastic NRK-49F cells treated with small interfering RNA (siRNA) for Hsc70. In the cells underexpressing Hsc70, transcriptional induction of connective tissue growth factor (CTGF), a target gene of the TGF-β signaling, was also suppressed in the early phase of TGF-β stimulation. Upon stimulation with TGF-β, Hsc70 interacted with Smad2/3, suggesting functional interactions of Hsc70 and Smad2/3 for the activation of TGF-β-inducedmore » Smad signaling. Although the expression of heat-shock protein 70 (Hsp70) was upregulated in the cells treated with Hsc70 siRNA, TGF-β-induced Smad activation was not affected in the cells overexpressing Hsp70. Collectively, these results indicate that Hsc70, but not Hsp70, supportively regulates TGF-β-induced Smad signaling in NRK-49F cells. - Highlights: • Hsc70 siRNA treatment suppressed the expression of Hsc70 but induced the expression of Hsp70 in NRK-49F cells. • Hsc70 siRNA treatment suppressed the activation of Smad2/3 in the cells treated with TGF-β. • Hsc70 interacted with Smad2/3 on stimulation with TGF-β in the cells. • Hsp70 did not influence the TGF-β-induced activation of Smad2/3 in the cells overexpressing Hsp70.« less
  • The transforming growth factor β isoforms, TGF-β1, -β2, and -β3, are small secreted homodimeric signaling proteins with essential roles in regulating the adaptive immune system and maintaining the extracellular matrix. However, dysregulation of the TGF-β pathway is responsible for promoting the progression of several human diseases, including cancer and fibrosis. Despite the known importance of TGF-βs in promoting disease progression, no inhibitors have been approved for use in humans. Herein, we describe an engineered TGF-β monomer, lacking the heel helix, a structural motif essential for binding the TGF-β type I receptor (TβRI) but dispensable for binding the other receptor requiredmore » for TGF-β signaling, the TGF-β type II receptor (TβRII), as an alternative therapeutic modality for blocking TGF-β signaling in humans. As shown through binding studies and crystallography, the engineered monomer retained the same overall structure of native TGF-β monomers and bound TβRII in an identical manner. Cell-based luciferase assays showed that the engineered monomer functioned as a dominant negative to inhibit TGF-β signaling with a Ki of 20–70 nM. Investigation of the mechanism showed that the high affinity of the engineered monomer for TβRII, coupled with its reduced ability to non-covalently dimerize and its inability to bind and recruit TβRI, enabled it to bind endogenous TβRII but prevented it from binding and recruiting TβRI to form a signaling complex. Such engineered monomers provide a new avenue to probe and manipulate TGF-β signaling and may inform similar modifications of other TGF-β family members.« less
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  • No abstract prepared.
  • Highlights: {yields} RLIM directly binds to Smurf2. {yields} RLIM enhances TGF-{beta} responsiveness in U2OS cells. {yields} RLIM promotes TGF-{beta} driven migration of osteosarcoma U2OS cells. -- Abstract: TGF-{beta} (transforming growth factor-{beta}), a pleiotropic cytokine that regulates diverse cellular processes, has been suggested to play critical roles in cell proliferation, migration, and carcinogenesis. Here we found a novel E3 ubiquitin ligase RLIM which can directly bind to Smurf2, enhancing TGF-{beta} responsiveness in osteosarcoma U2OS cells. We constructed a U2OS cell line stably over-expressing RLIM and demonstrated that RLIM promoted TGF-{beta}-driven migration of U2OS cells as tested by wound healing assay. Ourmore » results indicated that RLIM is an important positive regulator in TGF-{beta} signaling pathway and cell migration.« less