scholarly journals EGF receptor–mediated FUS phosphorylation promotes its nuclear translocation and fibrotic signaling

2020 ◽  
Vol 219 (9) ◽  
Author(s):  
Manuel Chiusa ◽  
Wen Hu ◽  
Jozef Zienkiewicz ◽  
Xiwu Chen ◽  
Ming-Zhi Zhang ◽  
...  
Keyword(s):  
Egf Receptor ◽  
Nuclear Translocation ◽  
Collagen Iv ◽  
Phosphorylation Sites ◽  
Kidney Fibrosis ◽  
Antifibrotic Therapy ◽  
Phosphorylated Proteins ◽  
Fused In Sarcoma ◽  
A Cell ◽  
Excessive Accumulation

Excessive accumulation of collagen leads to fibrosis. Integrin α1β1 (Itgα1β1) prevents kidney fibrosis by reducing collagen production through inhibition of the EGF receptor (EGFR) that phosphorylates cytoplasmic and nuclear proteins. To elucidate how the Itgα1β1/EGFR axis controls collagen synthesis, we analyzed the levels of nuclear tyrosine phosphorylated proteins in WT and Itgα1-null kidney cells. We show that the phosphorylation of the RNA-DNA binding protein fused in sarcoma (FUS) is higher in Itgα1-null cells. FUS contains EGFR-targeted phosphorylation sites and, in Itgα1-null cells, activated EGFR promotes FUS phosphorylation and nuclear translocation. Nuclear FUS binds to the collagen IV promoter, commencing gene transcription that is reduced by inhibiting EGFR, down-regulating FUS, or expressing FUS mutated in the EGFR-targeted phosphorylation sites. Finally, a cell-penetrating peptide that inhibits FUS nuclear translocation reduces FUS nuclear content and collagen IV transcription. Thus, EGFR-mediated FUS phosphorylation regulates FUS nuclear translocation and transcription of a major profibrotic collagen gene. Targeting FUS nuclear translocation offers a new antifibrotic therapy.

Phosphoproteome Analysis

2005 ◽  
Vol 25 (1-2) ◽  
pp. 33-44 ◽  
Author(s):  
Roberto Raggiaschi ◽  
Stefano Gotta ◽  
Georg C. Terstappen
Keyword(s):  
Mass Spectrometry ◽  
Affinity Chromatography ◽  
Protein Phosphorylation ◽  
Phosphorylation Sites ◽  
Specific Antibodies ◽  
Phosphorylated Proteins ◽  
Cellular Events ◽  
Phosphorylated Peptides ◽  
A Cell ◽  
Experimental Strategies

Protein phosphorylation is directly or indirectly involved in all important cellular events. The understanding of its regulatory role requires the discovery of the proteins involved in these processes and how, where and when protein phosphorylation takes place. Investigation of the phosphoproteome of a cell is becoming feasible today although it still represents a very difficult task especially if quantitative comparisons have to be made. Several different experimental strategies can be employed to explore phosphoproteomes and this review will cover the most important ones such as incorporation of radiolabeled phosphate into proteins, application of specific antibodies against phosphorylated residues and direct staining of phosphorylated proteins in polyacrylamide gels. Moreover, methods to enrich phosphorylated proteins such as affinity chromatography (IMAC) and immunoprecipitation as well as mass spectrometry for identification of phosphorylated peptides and phosphorylation sites are also described.

G-protein-coupled receptors signalling at the cell nucleus: an emerging paradigmThis paper is one of a selection of papers published in this Special Issue, entitled The Nucleus: A Cell Within A Cell.

2006 ◽  
Vol 84 (3-4) ◽  
pp. 287-297 ◽  
Author(s):  
Fernand Gobeil ◽  
Audrey Fortier ◽  
Tang Zhu ◽  
Michela Bossolasco ◽  
Martin Leduc ◽  
...  
Keyword(s):  
G Protein ◽  
Cell Nucleus ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Cell Metabolism ◽  
Hormone Secretion ◽  
G Protein Coupled Receptors ◽  
A Cell ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs) comprise a wide family of monomeric heptahelical glycoproteins that recognize a broad array of extracellular mediators including cationic amines, lipids, peptides, proteins, and sensory agents. Thus far, much attention has been given towards the comprehension of intracellular signaling mechanisms activated by cell membrane GPCRs, which convert extracellular hormonal stimuli into acute, non-genomic (e.g., hormone secretion, muscle contraction, and cell metabolism) and delayed, genomic biological responses (e.g., cell division, proliferation, and apoptosis). However, with respect to the latter response, there is compelling evidence for a novel intracrine mode of genomic regulation by GPCRs that implies either the endocytosis and nuclear translocation of peripheral-liganded GPCR and (or) the activation of nuclearly located GPCR by endogenously produced, nonsecreted ligands. A noteworthy example of the last scenario is given by heptahelical receptors that are activated by bioactive lipoids (e.g., PGE2 and PAF), many of which may be formed from bilayer membranes including those of the nucleus. The experimental evidence for the nuclear localization and signalling of GPCRs will be reviewed. We will also discuss possible molecular mechanisms responsible for the atypical compartmentalization of GPCRs at the cell nucleus, along with their role in gene expression.

scholarly journals Anti-Ace monoclonal antibody reduces Enterococcus faecalis aortic valve infection in a rat infective endocarditis model

2018 ◽  
Vol 76 (8) ◽  
Author(s):  
Kavindra V Singh ◽  
Kenneth L Pinkston ◽  
Peng Gao ◽  
Barrett R Harvey ◽  
Barbara E Murray
Keyword(s):  
Monoclonal Antibody ◽  
Infective Endocarditis ◽  
Enterococcus Faecalis ◽  
Collagen Iv ◽  
Aortic Valves ◽  
Collagen Binding ◽  
Passive Protection ◽  
A Cell ◽  
Pre Treatment

AbstractAce (Adhesin to collagen from Enterococcus faecalis) is a cell-wall anchored protein that is expressed conditionally and is important for virulence in a rat infective endocarditis (IE) model. Previously, we showed that rats immunized with the collagen binding domain of Ace (domain A), or administered anti-Ace domain A polyclonal antibody, were less susceptible to E. faecalis endocarditis than sham-immunized controls. In this work, we demonstrated that a sub nanomolar monoclonal antibody (mAb), anti-Ace mAb70, significantly diminished E. faecalis binding to ECM collagen IV in in vitro adherence assays and that, in the endocarditis model, anti-Ace mAb70 pre-treatment significantly reduced E. faecalis infection of aortic valves. The effectiveness of anti-Ace mAb against IE in the rat model suggests it might serve as a beneficial agent for passive protection against E. faecalis infections.

scholarly journals Irisin stimulates the release of CXCL1 from differentiating human subcutaneous and deep-neck derived adipocytes via upregulation of NFκB pathway

2021 ◽  
Author(s):  
Abhirup Shaw ◽  
Beáta B. Tóth ◽  
Robert Kiraly ◽  
Rini Arianti ◽  
István Csomós ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Cytokine Signaling ◽  
Beige Adipocytes ◽  
Neck Area ◽  
A Cell ◽  
Significant Release ◽  
Nfκb Pathway ◽  
Upregulated Genes ◽  
Differentiation Period ◽  
Positive Effect

Thermogenic brown and beige adipocytes play an important role in combating obesity. Recent studies in rodents and humans have indicated that these adipocytes release cytokines, termed "batokines". Irisin was discovered as a polypeptide regulator of beige adipocytes released by myocytes, primarily during exercise. We performed global RNA sequencing on adipocytes derived from human subcutaneous and deep-neck precursors, which were differentiated in the presence or absence of irisin. Irisin did not exert an effect on the expression of characteristic thermogenic genes, while upregulated genes belonging to various cytokine signaling pathways. Out of the several upregulated cytokines, CXCL1, the highest upregulated, was released throughout the entire differentiation period, and predominantly by differentiated adipocytes. Deep-neck area tissue biopsies also showed a significant release of CXCL1 during 24 hours irisin treatment. Gene expression data indicated upregulation of the NFκB pathway upon irisin treatment, which was validated by an increase of p50 and decrease of IκBα protein level, respectively. Continuous blocking of the NFκB pathway, using a cell permeable inhibitor of NFκB nuclear translocation, significantly reduced CXCL1 release. The released CXCL1 exerted a positive effect on the adhesion of endothelial cells. Together, our findings demonstrate that irisin stimulates the release of a novel "batokine", CXCL1, via upregulation of NFκB pathway in neck area derived adipocytes, which might play an important role in improving tissue vascularization.

The recombinant lectin-like domain of thrombomodulin inhibits angiogenesis through interaction with Lewis Y antigen

Blood ◽  
2012 ◽  
Vol 119 (5) ◽  
pp. 1302-1313 ◽  
Author(s):  
Cheng-Hsiang Kuo ◽  
Po-Ku Chen ◽  
Bi-Ing Chang ◽  
Meng-Chen Sung ◽  
Chung-Sheng Shi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Egf Receptor ◽  
Tube Formation ◽  
Endothelial Tube Formation ◽  
A Cell ◽  
Lewis Y ◽  
Tm Domain

AbstractLewis Y Ag (LeY) is a cell-surface tetrasaccharide that participates in angiogenesis. Recently, we demonstrated that LeY is a specific ligand of the recombinant lectin-like domain of thrombomodulin (TM). However, the biologic function of interaction between LeY and TM in endothelial cells has never been investigated. Therefore, the role of LeY in tube formation and the role of the recombinant lectin-like domain of TM—TM domain 1 (rTMD1)—in antiangiogenesis were investigated. The recombinant TM ectodomain exhibited lower angiogenic activity than did the recombinant TM domains 2 and 3. rTMD1 interacted with soluble LeY and membrane-bound LeY and inhibited soluble LeY-mediated chemotaxis of endothelial cells. LeY was highly expressed on membrane ruffles and protrusions during tube formation on Matrigel. Blockade of LeY with rTMD1 or Ab against LeY inhibited endothelial tube formation in vitro. Epidermal growth factor (EGF) receptor in HUVECs was LeY modified. rTMD1 inhibited EGF receptor signaling, chemotaxis, and tube formation in vitro, and EGF-mediated angiogenesis and tumor angiogenesis in vivo. We concluded that LeY is involved in vascular endothelial tube formation and rTMD1 inhibits angiogenesis via interaction with LeY. Administration of rTMD1 or recombinant adeno-associated virus vector carrying TMD1 could be a promising antiangiogenesis strategy.

scholarly journals Renoprotective effects of a novel cMet agonistic antibody on kidney fibrosis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yong Chul Kim ◽  
Junghun Lee ◽  
Jung Nam An ◽  
Jin Hyuk Kim ◽  
Young-Wook Choi ◽  
...  
Keyword(s):  
Kidney Diseases ◽  
Active Form ◽  
Kidney Injury ◽  
Biologically Active ◽  
Kidney Fibrosis ◽  
Proximal Tubular Epithelial Cells ◽  
Proximal Tubular ◽  
A Cell ◽  
Masson Trichrome Staining ◽  
Hepatocyte Growth

Abstract Hepatocyte growth factor (HGF) and its receptor, cMet, activate biological pathways necessary for repair and regeneration following kidney injury. Because HGF is a highly unstable molecule in its biologically active form, we asked whether a monoclonal antibody (Ab) that displays full agonist activity at the receptor could protect the kidney from fibrosis. We attempted to determine whether the cMet agonistic Ab might reduce fibrosis, the final common pathway for chronic kidney diseases (CKD). A mouse model of kidney fibrosis disease induced by unilateral ureteral obstruction was introduced and subsequently validated with primary cultured human proximal tubular epithelial cells (PTECs). In kidney biopsy specimens from patients with CKD, cMet immunohistochemistry staining showed a remarkable increase compared with patients with normal renal functions. cMet Ab treatment significantly increased the levels of phospho-cMet and abrogated the protein expression of fibrosis markers such as fibronectin, collagen 1, and αSMA as well as Bax2, which is a marker of apoptosis triggered by recombinant TGF-β1 in PTECs. Remarkably, injections of cMet Ab significantly prevented kidney fibrosis in obstructed kidneys as quantified by Masson trichrome staining. Consistent with these data, cMet Ab treatment decreased the expression of fibrosis markers, such as collagen1 and αSMA, whereas the expression of E-cadherin, which is a cell-cell adhesion molecule, was restored. In conclusion, cMet-mediated signaling may play a considerable role in kidney fibrosis. Additionally, the cMet agonistic Ab may be a valuable substitute for HGF because it is more easily available in a biologically active, stable, and purified form.

scholarly journals The Ser/Thr kinase p90RSK promotes kidney fibrosis by modulating fibroblast–epithelial crosstalk

2019 ◽  
Vol 294 (25) ◽  
pp. 9901-9910 ◽  
Author(s):  
Ling Lin ◽  
Chaowen Shi ◽  
Zhaorui Sun ◽  
Nhat-Tu Le ◽  
Jun-Ichi Abe ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Nuclear Translocation ◽  
Disease Model ◽  
Kidney Fibrosis ◽  
Cellular Processes ◽  
Ribosomal Protein S6 ◽  
Forkhead Box

Healthy kidney structure and environment rely on epithelial integrity and interactions between epithelial cells and other kidney cells. The Ser/Thr kinase 90 kDa ribosomal protein S6 kinase 1 (p90RSK) belongs to a protein family that regulates many cellular processes, including cell motility and survival. p90RSK is predominantly expressed in the kidney, but its possible role in chronic kidney disease (CKD) remains largely unknown. Here, we found that p90RSK expression is dramatically activated in a classic mouse obstructive chronic kidney disease model, largely in the interstitial FSP-1–positive fibroblasts. We generated FSP-1–specific p90RSK transgenic mouse (RSK-Tg) and discovered that these mice, after obstructive injury, display significantly increased fibrosis and enhanced tubular epithelial damage compared with their wt littermates (RSK-wt), indicating a role of p90RSK in fibroblast–epithelial communication. We established an in vitro fibroblast–epithelial coculture system with primary kidney fibroblasts from RSK-Tg and RSK-wt mice and found that RSK-Tg fibroblasts consistently produce excessive H2O2 causing epithelial oxidative stress and inducing nuclear translocation of the signaling protein β-catenin. Epithelial accumulation of β-catenin, in turn, promoted epithelial apoptosis by activating the transcription factor forkhead box class O1 (FOXO1). Of note, blockade of reactive oxygen species (ROS) or β-catenin or FOXO1 activity abolished fibroblast p90RSK-mediated epithelial apoptosis. These results make it clear that p90RSK promotes kidney fibrosis by inducing fibroblast-mediated epithelial apoptosis through ROS-mediated activation of β-catenin/FOXO1 signaling pathway.

scholarly journals Proteomic determination of the lysine acetylome and phosphoproteome in the rat native inner medullary collecting duct

2018 ◽  
Vol 50 (9) ◽  
pp. 669-679 ◽  
Author(s):  
Kelly A. Hyndman ◽  
Chin-Rang Yang ◽  
Hyun Jun Jung ◽  
Ezigbobiara N. Umejiego ◽  
Chung-Ling Chou ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Collecting Duct ◽  
Water Channel ◽  
Receptor Activation ◽  
Phosphorylation Sites ◽  
Water Reabsorption ◽  
Inner Medullary Collecting Duct ◽  
Phosphorylated Proteins ◽  
V2 Receptor ◽  
Medullary Collecting Duct

Phosphorylation and lysine (K)-acetylation are dynamic posttranslational modifications of proteins. Previous proteomic studies have identified over 170,000 phosphorylation sites and 15,000 K-acetylation sites in mammals. We recently reported that the inner medullary collecting duct (IMCD), which functions in the regulation of water-reabsorption, via the actions of vasopressin, expresses many of the enzymes that can modulated K-acetylation. The purpose of this study was to determine the K-acetylated or phosphorylated proteins expressed in IMCD cells. Second we questioned whether vasopressin V2 receptor activation significantly affects the IMCD acetylome or phosphoproteome? K-acetylated or serine-, threonine-, or tyrosine-phosphorylated peptides were identified from native rat IMCDs by proteomic analysis with four different enzymes (trypsin, chymotrypsin, ASP-N, or Glu-C) to generate a high-resolution proteome. K-acetylation was identified in 431 unique proteins, and 64% of the K-acetylated sites were novel. The acetylated proteins were expressed in all compartments of the cell and were enriched in pathways including glycolysis and vasopressin-regulated water reabsorption. In the vasopressin-regulated water reabsorption pathway, eight proteins were acetylated, including the novel identification of the basolateral water channel, AQP3, acetylated at K282; 215 proteins were phosphorylated in this IMCD cohort, including AQP2 peptides that were phosphorylated at four serines: 256, 261, 264, and 269. Acute dDAVP did not significantly affect the IMCD acetylome; however, it did significantly affect previously known vasopressin-regulated phosphorylation sites. In conclusion, presence of K-acetylated proteins involved in metabolism, ion, and water transport in the IMCD points to multiple roles of K-acetylation beyond its canonical role in transcriptional regulation.

scholarly journals The Anaphase Promoting Complex Targeting Subunit Ama1 Links Meiotic Exit to Cytokinesis during Sporulation inSaccharomyces cerevisiae

2009 ◽  
Vol 20 (1) ◽  
pp. 134-145 ◽  
Author(s):  
Aviva E. Diamond ◽  
Jae-Sook Park ◽  
Ichiro Inoue ◽  
Hiroyuki Tachikawa ◽  
Aaron M. Neiman
Keyword(s):  
Cell Division ◽  
Plasma Membranes ◽  
Leading Edge ◽  
Phosphorylation Sites ◽  
Cyclin Dependent Kinase ◽  
Anaphase Promoting Complex ◽  
Prospore Membrane ◽  
A Cell ◽  
Essential Function ◽  
Kinase Phosphorylation

Ascospore formation in yeast is accomplished through a cell division in which daughter nuclei are engulfed by newly formed plasma membranes, termed prospore membranes. Closure of the prospore membrane must be coordinated with the end of meiosis II to ensure proper cell division. AMA1 encodes a meiosis-specific activator of the anaphase promoting complex (APC). The activity of APCAma1is inhibited before meiosis II, but the substrates specifically targeted for degradation by Ama1 at the end of meiosis are unknown. We show here that ama1Δ mutants are defective in prospore membrane closure. Ssp1, a protein found at the leading edge of the prospore membrane, is stabilized in ama1Δ mutants. Inactivation of a conditional form of Ssp1 can partially rescue the sporulation defect of the ama1Δ mutant, indicating that an essential function of Ama1 is to lead to the removal of Ssp1. Depletion of Cdc15 causes a defect in meiotic exit. We find that prospore membrane closure is also defective in Cdc15 and that this defect can be overcome by expression of a form of Ama1 in which multiple consensus cyclin-dependent kinase phosphorylation sites have been mutated. These results demonstrate that APCAma1functions to coordinate the exit from meiosis II with cytokinesis.

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