scholarly journals Enterohepatic Transcription Factor CREB3L3 Protects Atherosclerosis via SREBP Competitive Inhibition

2020 ◽  
Author(s):  
Yoshimi Nakagawa ◽  
Yunong Wang ◽  
Song-iee Han ◽  
Kanako Okuda ◽  
Asayo Oishi ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Competitive Inhibition ◽  
Intestinal Transport ◽  
Protective Effects ◽  
Proteolytic Activation ◽  
Golgi Transport ◽  
Aortic Atheroma ◽  
Er Retention ◽  
Membrane Bound ◽  
Specific Deletion

SummaryCREB3L3 is a membrane-bound transcription factor to maintain lipid metabolism in the liver and small intestine. CREB3L3 ablation in Ldlr-/- mice exacerbated hyperlipidemia with remnant ApoB-containing lipoprotein accumulation, developing enhanced aortic atheroma formation, whose extent was additive between liver- and intestine-specific deletion. Conversely, hepatic nuclear CREB3L3 overexpression markedly suppressed atherosclerosis with amelioration of hyperlipidemia. CREB3L3 directly upregulates anti-atherogenic FGF21 and ApoA4, whereas antagonizes hepatic SREBP-mediated lipogenic and cholesterogenic genes and regulates LXR-regulated genes involved in intestinal transport of cholesterol. CREB3L3 deficiency accumulates nuclear SREBP proteins. Because both transcriptional factors share the cleavage system for nuclear transactivation, full-length CREB3L3 and SREBPs on endoplasmic reticulum (ER) functionally inhibit each other. CREB3L3 competitively antagonizes SREBPs for ER-Golgi transport, resulting in ER retention and proteolytic activation inhibition at Golgi, and vice versa. Collectively, due to this new mechanistic interaction between CREB3L3 and SREBPs under atherogenic conditions, CREB3L3 has multi-potent protective effects against atherosclerosis.

scholarly journals GSK-3–mediated phosphorylation couples ER–Golgi transport and nuclear stabilization of the CREB-H transcription factor to mediate apolipoprotein secretion

2017 ◽  
Vol 28 (11) ◽  
pp. 1565-1579 ◽  
Author(s):  
Sónia Barbosa ◽  
Suzanne Carreira ◽  
Peter O’Hare
Keyword(s):  
Transcription Factor ◽  
Nuclear Import ◽  
Metabolic Pathways ◽  
Secretory Pathway ◽  
Integrated Control ◽  
Active Form ◽  
Transcriptional Responses ◽  
Golgi Transport ◽  
Er Retention ◽  
Drug Inhibition

CREB-H, an ER-anchored transcription factor, plays a key role in regulating secretion in metabolic pathways, particularly triglyceride homeostasis. It controls the production both of secretory pathway components and cargoes, including apolipoproteins ApoA-IV and ApoC-II, contributing to VLDL/HDL distribution and lipolysis. The key mechanism controlling CREB-H activity involves its ER retention and forward transport to the Golgi, where it is cleaved by Golgi-resident proteases, releasing the N-terminal product, which traffics to the nucleus to effect transcriptional responses. Here we show that a serine-rich motif termed the P-motif, located in the N-terminus between serines 73 and 90, controls release of the precursor transmembrane form from the ER and its forward transport to the Golgi. This motif is subject to GSK-3 phosphorylation, promoting ER retention, while mutation of target serines and drug inhibition of GSK-3 activity coordinately induce both forward transport of the precursor and cleavage, resulting in nuclear import. We previously showed that for the nuclear product, the P-motif is subject to multiple phosphorylations, which regulate stability by targeting the protein to the SCFFbw1a E3 ubiquitin ligase. Thus phosphorylation at the P-motif provides integrated control of CREB-H function, coupling intercompartmental transport in the cytoplasm with stabilization of the active form in the nucleus.

scholarly journals N-linked glycosylation is required for optimal proteolytic activation of membrane-bound transcription factor CREB-H

2010 ◽  
Vol 123 (9) ◽  
pp. 1438-1448 ◽  
Author(s):  
C.-P. Chan ◽  
T.-Y. Mak ◽  
K.-T. Chin ◽  
I. O.-L. Ng ◽  
D.-Y. Jin
Keyword(s):  
Transcription Factor ◽  
Proteolytic Activation ◽  
Membrane Bound

scholarly journals Arsenic nano complex induced degradation of YAP sensitized ESCC cancer cells to radiation and chemotherapy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wei Zhou ◽  
Meiyue Liu ◽  
Xia Li ◽  
Peng Zhang ◽  
Jiong Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Radiation Therapy ◽  
Cancer Cells ◽  
Solid Tumors ◽  
Xenograft Model ◽  
Ros Production ◽  
Protective Effects ◽  
Migration Ability ◽  
Mouse Xenograft ◽  
Mouse Xenograft Model

Abstract Background Increased reactive oxygen species (ROS) production by arsenic treatment in solid tumors showed to be effective to sensitize cancer cells to chemotherapies. Arsenic nano compounds are known to increase the ROS production in solid tumors. Methods In this study we developed arsenic–ferrosoferric oxide conjugated Nano Complex (As2S2–Fe3O4, AFCNC) to further promote the ROS induction ability of arsenic reagent in solid tumors. We screen for the molecular pathways that are affect by arsenic treatment in ESCC cancer cells. And explored the underlying molecular mechanism for the arsenic mediated degradations of the key transcription factor we identified in the gene microarray screen. Mouse xenograft model were used to further verify the synthetic effects of AFCNC with chemo and radiation therapies, and the molecular target of arsenic treatment is verified with IHC analysis. Results With gene expression microarray analysis we found Hippo signaling pathway is specifically affected by arsenic treatment, and induced ubiquitination mediated degradation of YAP in KYSE-450 esophageal squamous cell carcinoma (ESCC) cells. Mechanistically we proved PML physically interacted with YAP, and arsenic induced degradation PML mediated the degradation of YAP in ESCC cells. As a cancer stem cell related transcription factor, YAP 5SA over expressions in cancer cells are correlated with resistance to chemo and radiation therapies. We found AFCNC treatment inhibited the increased invasion and migration ability of YAP 5SA overexpressing KYSE-450 cells. AFCNC treatment also effectively reversed protective effects of YAP 5SA overexpression against cisplatin induced apoptosis in KYSE-450 cells. Lastly, with ESCC mouse xenograft model we found AFCNC combined with cisplatin treatment or radiation therapy significantly reduced the tumor volumes in vivo in the xenograft ESCC tumors. Conclusions Together, these findings suggested besides ROS, YAP is a potential target for arsenic based therapy in ESCC, which should play an important role in the synthetic effects of arsenic nano complex with chemo and radiation therapy.

scholarly journals PRKAR2A deficiency protects mice from experimental colitis by increasing IFN-stimulated gene expression and modulating the intestinal microbiota

2021 ◽  
Author(s):  
Lumin Wei ◽  
Rongjing Zhang ◽  
Jinzhao Zhang ◽  
Juanjuan Li ◽  
Deping Kong ◽  
...  
Keyword(s):  
Experimental Colitis ◽  
Regulatory Subunit ◽  
Protective Effects ◽  
Intestinal Epithelial ◽  
Catalytic Subunits ◽  
Regulatory Subunits ◽  
Pka Regulatory Subunit ◽  
Cross Fostering ◽  
Specific Deletion

AbstractProtein kinase A (PKA) plays an important role in regulating inflammation via its catalytic subunits. Recently, PKA regulatory subunits have been reported to directly modulate some signaling pathways and alleviate inflammation. However, the role of PKA regulatory subunits in colonic inflammation remains unclear. Therefore, we conducted this study to investigate the role of the PKA regulatory subunit PRKAR2A in colitis. We observed that PRKAR2A deficiency protected mice from dextran sulfate sodium (DSS)-induced experimental colitis. Our experiments revealed that the intestinal epithelial cell-specific deletion of Prkar2a contributed to this protection. Mechanistically, the loss of PRKAR2A in Prkar2a−/− mice resulted in an increased IFN-stimulated gene (ISG) expression and altered gut microbiota. Inhibition of ISGs partially reversed the protective effects against DSS-induced colitis in Prkar2a−/− mice. Antibiotic treatment and cross-fostering experiments demonstrated that the protection against DSS-induced colitis in Prkar2a−/− mice was largely dependent on the gut microflora. Altogether, our work demonstrates a previously unidentified function of PRKAR2A in promoting DSS-induced colitis.

scholarly journals Systems analysis of transcription factor activities in environments with stable and dynamic oxygen concentrations

Open Biology ◽  
2012 ◽  
Vol 2 (7) ◽  
pp. 120091 ◽  
Author(s):  
Matthew D. Rolfe ◽  
Andrea Ocone ◽  
Melanie R. Stapleton ◽  
Simon Hall ◽  
Eleanor W. Trotter ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Systems Analysis ◽  
Kinetic Modelling ◽  
Statistical Modelling ◽  
Spatial Effects ◽  
Transcript Profile ◽  
Terminal Oxidases ◽  
Adaptive Processes ◽  
Membrane Bound ◽  
Transcript Profiles

Understanding gene regulation requires knowledge of changes in transcription factor (TF) activities. Simultaneous direct measurement of numerous TF activities is currently impossible. Nevertheless, statistical approaches to infer TF activities have yielded non-trivial and verifiable predictions for individual TFs. Here, global statistical modelling identifies changes in TF activities from transcript profiles of Escherichia coli growing in stable (fixed oxygen availabilities) and dynamic (changing oxygen availability) environments. A core oxygen-responsive TF network, supplemented by additional TFs acting under specific conditions, was identified. The activities of the cytoplasmic oxygen-responsive TF, FNR, and the membrane-bound terminal oxidases implied that, even on the scale of the bacterial cell, spatial effects significantly influence oxygen-sensing. Several transcripts exhibited asymmetrical patterns of abundance in aerobic to anaerobic and anaerobic to aerobic transitions. One of these transcripts, ndh , encodes a major component of the aerobic respiratory chain and is regulated by oxygen-responsive TFs ArcA and FNR. Kinetic modelling indicated that ArcA and FNR behaviour could not explain the ndh transcript profile, leading to the identification of another TF, PdhR, as the source of the asymmetry. Thus, this approach illustrates how systematic examination of regulatory responses in stable and dynamic environments yields new mechanistic insights into adaptive processes.

Proteolytic activation of membrane-bound guanylate cyclase

2001 ◽  
Vol 61 (7) ◽  
pp. 915-920 ◽  
Author(s):  
Zi-Jiang Chen ◽  
Dong-Li Song ◽  
Zhenhua Miao ◽  
Chung-Ho Chang
Keyword(s):  
Guanylate Cyclase ◽  
Proteolytic Activation ◽  
Membrane Bound

scholarly journals Activation of transcription factor NF-kappaB by the adenovirus E3/19K protein requires its ER retention.

1996 ◽  
Vol 132 (4) ◽  
pp. 511-522 ◽  
Author(s):  
H L Pahl ◽  
M Sester ◽  
H G Burgert ◽  
P A Baeuerle
Keyword(s):  
Transcription Factor ◽  
Cell Surface ◽  
Mhc Class I ◽  
Signal Sequence ◽  
Signal Transduction Pathway ◽  
Cyclopiazonic Acid ◽  
Class I ◽  
Mhc Molecules ◽  
Er Retention ◽  
Nf Kappab

We have recently shown that the accumulation of diverse viral and cellular membrane proteins in the ER activates the higher eukaryotic transcription factor NF-kappaB. This defined a novel ER-nuclear signal transduction pathway, which is distinct from the previously described unfolded protein response (UPR). The well characterized UPR pathway is activated by the presence of un- or malfolded proteins in the ER. In contrast, the ER stress signal which activates the NF-kappaB pathway is not known. Here we used the adenovirus early region protein E3/19K as a model to investigate the nature of the NF-kappaB-activating signal emitted by the ER. E3/19K resides in the endoplasmic reticulum where it binds to MHC class I molecules, thereby preventing their transport to the cell surface. It is maintained in the ER by a retention signal sequence in its carboxy terminus, which causes the protein to be continuously retrieved to the ER from post-ER compartments. Mutation of this sequence allows E3/19K to reach the cell surface. We show here that expression of E3/19K potently activates a functional NF-kappaB transcription factor. The activated NF-kappaB complexes contained p50/p65 and p50/c-rel heterodimers. E3/19K interaction with MHC class I was not important for NF-kappaB activation since mutant proteins which no longer bind MHC molecules remained fully capable of inducing NF-kappaB. However, activation of both NF-kappaB DNA binding and kappaB-dependent transactivation relied on E3/19K ER retention: mutants, which were expressed on the cell surface, could no longer activate the transcription factor. This identifies the NF-kappaB-activating signal as the accumulation of proteins in the ER membrane, a condition we have termed "ER overload." We show that ER overload-mediated NF-kappaB activation but not TNF-stimulated NF-kappaB induction can be inhibited by the intracellular Ca2+ chelator TMB-8. Moreover, treatment of cells with two inhibitors of the ER-resident Ca(2+) -dependent ATPase, thapsigargin and cyclopiazonic acid, which causes a rapid release of Ca2+ from the ER, strongly activated NF-kappaB. We therefore propose that ER overload activates NF-kappaB by causing Ca2+ release from the ER. Because NF-kappaB plays a key role in mounting an immune response, ER overload caused by viral proteins may constitute a simple antiviral response with broad specificity.

scholarly journals Gata2 is required for HSC generation and survival

2013 ◽  
Vol 210 (13) ◽  
pp. 2843-2850 ◽  
Author(s):  
Emma de Pater ◽  
Polynikis Kaimakis ◽  
Chris S. Vink ◽  
Tomomasa Yokomizo ◽  
Tomoko Yamada-Inagawa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transcription Factor ◽  
Developmental Stages ◽  
Vascular Endothelial ◽  
Vascular Integrity ◽  
Hematopoietic Stem ◽  
Vascular Endothelial Cadherin ◽  
Umbilical Arteries ◽  
Specific Deletion

Knowledge of the key transcription factors that drive hematopoietic stem cell (HSC) generation is of particular importance for current hematopoietic regenerative approaches and reprogramming strategies. Whereas GATA2 has long been implicated as a hematopoietic transcription factor and its dysregulated expression is associated with human immunodeficiency syndromes and vascular integrity, it is as yet unknown how GATA2 functions in the generation of HSCs. HSCs are generated from endothelial cells of the major embryonic vasculature (aorta, vitelline, and umbilical arteries) and are found in intra-aortic hematopoietic clusters. In this study, we find that GATA2 function is essential for the generation of HSCs during the stage of endothelial-to-hematopoietic cell transition. Specific deletion of Gata2 in Vec (Vascular Endothelial Cadherin)-expressing endothelial cells results in a deficiency of long-term repopulating HSCs and intra-aortic cluster cells. By specific deletion of Gata2 in Vav-expressing hematopoietic cells (after HSC generation), we further show that GATA2 is essential for HSC survival. This is in contrast to the known activity of the RUNX1 transcription factor, which functions only in the generation of HSCs, and highlights the unique requirement for GATA2 function in HSCs throughout all developmental stages.

Anti-Apoptotic and Anti-Inflammatory Activities of Edible Fresh Water Algae Prasiola japonica in UVB-Irradiated Skin Keratinocytes

2019 ◽  
Vol 47 (08) ◽  
pp. 1853-1868
Author(s):  
Eunju Choi ◽  
Young-Su Yi ◽  
Jongsung Lee ◽  
Sang Hee Park ◽  
Sunggyu Kim ◽  
...  
Keyword(s):  
Fresh Water ◽  
Ethanol Extract ◽  
The Body ◽  
Hacat Cells ◽  
Protective Effects ◽  
Proteolytic Activation ◽  
Skin Keratinocytes ◽  
External Stresses ◽  
Anti Oxidant ◽  
Anti Inflammatory

Skin is the outer tissue layer and is a barrier protecting the body from various external stresses. The fresh water green edible algae Prasiola japonica has antiviral, antimicrobial, and anti-inflammatory properties; however, few studies of its effects on skin-protection have been reported. In this study, Prasiola japonica ethanol extract (Pj-EE) was prepared, and its skin-protective properties were investigated in skin keratinocytes. Pj-EE inhibited ROS production in UVB-irradiated HaCaT cells without cytotoxicity. Pj-EE also suppressed the apoptotic death of UVB-irradiated HaCaT cells by decreasing the generation of apoptotic bodies and the proteolytic activation of apoptosis caspase-3, -8, and -9. Moreover, Pj-EE downregulated the mRNA expression of the inflammatory gene cyclooxygenase-2 (COX-2), the pro-inflammatory cytokine genes interleukin (IL)-1[Formula: see text], IL-8, IL-6, tumor necrosis factor (TNF)-[Formula: see text], and interferon (IFN)-[Formula: see text], and the tissue remodeling genes matrix metalloproteinase (MMP)-1, -2, -3, and -9. The Pj-EE-induced anti-inflammatory effect was mediated by suppressing the activation of nuclear factor-kappa B (NF-[Formula: see text]B) signaling pathway in the UVB-irradiated HaCaT cells. Taken together, these results suggest that Pj-EE exerts skin-protective effects through anti-oxidant, anti-apoptotic, and anti-inflammatory activities in skin keratinocytes.

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