scholarly journals Prodomain-Growth Factor Swapping in the Structure of pro-TGF-β1

2017 ◽  
Author(s):  
Bo Zhao ◽  
Shutong Xu ◽  
Xianchi Dong ◽  
Chafen Lu ◽  
Timothy A. Springer

AbstractTransforming growth factor (TGF)-β is synthesized as a proprotein that dimerizes in the endoplasmic reticulum. After processing in the Golgi to cleave the N-terminal prodomain from the C-terminal growth factor (GF) domain in each monomer, pro-TGF-β is secreted and stored in latent complexes. It is unclear which prodomain and GF monomer are linked prior to proprotein convertase (PC) cleavage, and how much conformational change occurs following cleavage. We have determined a structure of pro-TGF-β1 with the PC cleavage site mutated, to mimic the structure of the TGF-β1 proprotein. Our structure demonstrates that the prodomain arm domain in one monomer is linked to the GF that interacts with the arm domain in the other monomer in the dimeric structure, i.e., the prodomain arm domain and GF domain in each monomer are swapped. Swapping has important implications for the mechanism of biosynthesis in the TGF-β family and is relevant to the mechanism for preferential formation of heterodimers over homodimers for some members of the TGF-β family. Our structure also provides comparisons between independent TGF-β1 crystal structures and between human and porcine pro-TGF-β1.

2003 ◽  
Vol 371 (1) ◽  
pp. 211-221 ◽  
Author(s):  
J⊘rgen OLSEN ◽  
Lene T. KIRKEBY ◽  
Marianne M. BRORSSON ◽  
Sally DABELSTEEN ◽  
Jesper T. TROELSEN ◽  
...  

The trimeric extracellular matrix molecule laminin-5 and its constituent chains (α3, β3, γ2) are normally not detectable intracellularly in intestinal epithelial cells but the laminin γ2 chain can be detected in cancer cells at the invasive front of a subset of colon carcinomas. These cells are subjected to cytokines such as transforming growth factor β1 (TGF-β1) and hepatocyte growth factor (HGF), produced by the tumour cells or by the surrounding stromal cells. The purpose of the present work was to investigate whether TGF-β1 and HGF, known to stimulate the LAMC2 gene encoding the laminin γ2 chain, might synergize to activate the LAMC2 promoter, and to identify the promoter elements involved. We find evidence for synergy between TGF-β and HGF with respect to laminin γ2 chain expression and promoter activation and demonstrate that this requires the 5′ activator protein-1 (AP-1) element of the promoter and an additional upstream element which is also responsive to co-expression of the Smad3 protein from the TGF-β signalling pathway. The transcripts encoding the other laminin-5 chains are not synergistically activated by HGF and TGF-β. Thus the synergistic activation of the LAMC2 gene is mediated via different cis-elements and results in an overproduction of the laminin γ2 chain relative to the other laminin-5 constituent chains. This difference may explain why laminin γ2 chains accumulate in the cells at the invasive front of colon carcinomas.


2021 ◽  
Vol 11 (19) ◽  
pp. 9128
Author(s):  
Jwa-Young Kim ◽  
Dae-Won Kim ◽  
Suk Keun Lee ◽  
Je-Yong Choi ◽  
Xiangguo Che ◽  
...  

In our previous study, 4-hexylresorcinol (4HR) increased the expression level of vascular endothelial growth factor in human umbilical vein endothelial cells (HUVECs) via the transforming growth factor-β1 (TGF-β1)-mediated pathway. Endoplasmic reticulum (ER) and mitochondrial stress is a positive regulator of cellular differentiation. As TGF-β1 is a master regulator for cellular differentiation, 4HR treatment may increase TGF-β1 expression via ER stress. In this study, HUVECs were treated using 4HR (1–100 μM) for 24 h. The 4HR treatment increased ER stress-associated markers and mitochondrial stress. Increased TGF-β1 expression by 4HR administration was alleviated by tauroursodeoxycholate (ER stress inhibitor) treatment. Combining these activities with the elevated acetylation level of histone 3 (H3) by 4HR treatment, TGF-β1 expression was increased in HUVECs. Overall, 4HR increased TGF-β1 expression through upregulation of the stress response of ER as well as H3 acetylation in HUVECs.


2021 ◽  
Vol 22 (6) ◽  
pp. 2952
Author(s):  
Tzu-Yu Hou ◽  
Shi-Bei Wu ◽  
Hui-Chuan Kau ◽  
Chieh-Chih Tsai

Transforming growth factor-β1 (TGF-β1)-induced myofibroblast transdifferentiation from orbital fibroblasts is known to dominate tissue remodeling and fibrosis in Graves’ ophthalmopathy (GO). However, the signaling pathways through which TGF-β1 activates Graves’ orbital fibroblasts remain unclear. This study investigated the role of the mitogen-activated protein kinase (MAPK) pathway in TGF-β1-induced myofibroblast transdifferentiation in human Graves’ orbital fibroblasts. The MAPK pathway was assessed by measuring the phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular-signal-regulated kinase (ERK) by Western blots. The expression of connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), and fibronectin representing fibrogenesis was estimated. The activities of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) responsible for extracellular matrix (ECM) metabolism were analyzed. Specific pharmacologic kinase inhibitors were used to confirm the involvement of the MAPK pathway. After treatment with TGF-β1, the phosphorylation levels of p38 and JNK, but not ERK, were increased. CTGF, α-SMA, and fibronectin, as well as TIMP-1 and TIMP-3, were upregulated, whereas the activities of MMP-2/-9 were inhibited. The effects of TGF-β1 on the expression of these factors were eliminated by p38 and JNK inhibitors. The results suggested that TGF-β1 could induce myofibroblast transdifferentiation in human Graves’ orbital fibroblasts through the p38 and JNK pathways.


2021 ◽  
Vol 22 (5) ◽  
pp. 2580
Author(s):  
Won Kil Lee ◽  
Yeongyeong Kim ◽  
Heejin Jang ◽  
Joo Hye Sim ◽  
Hye Jin Choi ◽  
...  

Myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) is one of the most refractory diseases in humans and is characterized by severe central fatigue accompanied with various symptoms that affect daily life, such as impaired memory, depression, and somatic pain. However, the etiology and pathophysiological mechanisms of CFS remain unknown. To investigate the pathophysiological role of transforming growth factor (TGF)-β1, we injected a cytokine into the lateral ventricle of a C57BL/6 mouse. The intracranial injection of TGF-β1 increased the immobility duration in a forced swimming test (FST) and time spent at the closed arm in elevated plus maze (EPM) analysis. The mice injected with TGF-β1 into their brain showed increased sensitivity to pain in a von Frey test, and had a decreased retention time on rotarod and latency time in a bright box in a passive avoidance test. In addition, the serum levels of muscle fatigue biomarkers, lactate dehydrogenase (LDH) and creatine kinase (CK), were significantly increased after administration of TGF-β1. Intracranial injection of TGF-β1 significantly reduced the production of tyrosine hydroxylase (TH) in the ventral tegmental area, accompanied by a decreased level of dopamine in the striatum. The suppression of TH expression by TGF-β1 was confirmed in the human neuroblastoma cell line, SH-SY5Y. These results, which show that TGF-β1 induced fatigue-like behaviors by suppressing dopamine production, suggest that TGF-β1 plays a critical role in the development of central fatigue and is, therefore, a potential therapeutic target of the disease.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yueyi Yang ◽  
Wenjing Liu ◽  
JieYa Wei ◽  
Yujia Cui ◽  
Demao Zhang ◽  
...  

AbstractGap junction (GJ) has been indicated to have an intimate correlation with adhesion junction. However, the direct interaction between them partially remains elusive. In the current study, we aimed to elucidate the role of N-cadherin, one of the core components in adhesion junction, in mediating connexin 43, one of the functional constituents in gap junction, via transforming growth factor-β1(TGF-β1) induction in osteoblasts. We first elucidated the expressions of N-cadherin induced by TGF-β1 and also confirmed the upregulation of Cx43, and the enhancement of functional gap junctional intercellular communication (GJIC) triggered by TGF-β1 in both primary osteoblasts and MC3T3 cell line. Colocalization analysis and Co-IP experimentation showed that N-cadherin interacts with Cx43 at the site of cell–cell contact. Knockdown of N-cadherin by siRNA interference decreased the Cx43 expression and abolished the promoting effect of TGF-β1 on Cx43. Functional GJICs in living primary osteoblasts and MC3T3 cell line were also reduced. TGF-β1-induced increase in N-cadherin and Cx43 was via Smad3 activation, whereas knockdown of Smad3 signaling by using siRNA decreased the expressions of both N-cadherin and Cx43. Overall, these data indicate the direct interactions between N-cadherin and Cx43, and reveal the intervention of adhesion junction in functional gap junction in living osteoblasts.


2021 ◽  
Vol 49 (3) ◽  
pp. 030006052199651
Author(s):  
Jie Yang ◽  
Enzi Feng ◽  
Yanxin Ren ◽  
Shun Qiu ◽  
Liufang Zhao ◽  
...  

Objectives To identify key long non-coding (lnc)RNAs responsible for the epithelial–mesenchymal transition (EMT) of CNE1 nasopharyngeal carcinoma cells and to investigate possible regulatory mechanisms in EMT. Methods CNE1 cells were divided into transforming growth factor (TGF)-β1-induced EMT and control groups. The mRNA and protein expression of EMT markers was determined by real-time quantitative PCR and western blotting. Differentially expressed genes (DEGs) between the two groups were identified by RNA sequencing analysis, and DEG functions were analyzed by gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses. EMT marker expression was re-evaluated by western blotting after knockdown of a selected lncRNA. Results TGF-β1-induced EMT was characterized by decreased E-cadherin and increased vimentin, N-cadherin, and Twist expression at both mRNA and protein levels. Sixty lncRNA genes were clustered in a heatmap, and mRNA expression of 14 dysregulated lncRNAs was consistent with RNA sequencing. Knockdown of lnc-PNRC2-1 increased expression of its antisense gene MYOM3 and reduced expression of EMT markers, resembling treatment with the TGF-β1 receptor inhibitor LY2109761. Conclusion Various lncRNAs participated indirectly in the TGF-β1-induced EMT of CNE1 cells. Lnc-PNRC2-1 may be a key regulator of this and is a potential target to alleviate CNE1 cell EMT.


1998 ◽  
Vol 77 (9) ◽  
pp. 1492-1494 ◽  
Author(s):  
K Krasagakis ◽  
D Thölke ◽  
B Farthmann ◽  
J Eberle ◽  
U Mansmann ◽  
...  

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