scholarly journals YOD1/TRAF6 association balances p62-dependent IL-1 signaling to NF-κB

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Gisela Schimmack ◽  
Kenji Schorpp ◽  
Kerstin Kutzner ◽  
Torben Gehring ◽  
Jara Kerstin Brenke ◽  
...  

The ubiquitin ligase TRAF6 is a key regulator of canonical IκB kinase (IKK)/NF-κB signaling in response to interleukin-1 (IL-1) stimulation. Here, we identified the deubiquitinating enzyme YOD1 (OTUD2) as a novel interactor of TRAF6 in human cells. YOD1 binds to the C-terminal TRAF homology domain of TRAF6 that also serves as the interaction surface for the adaptor p62/Sequestosome-1, which is required for IL-1 signaling to NF-κB. We show that YOD1 competes with p62 for TRAF6 association and abolishes the sequestration of TRAF6 to cytosolic p62 aggregates by a non-catalytic mechanism. YOD1 associates with TRAF6 in unstimulated cells but is released upon IL-1β stimulation, thereby facilitating TRAF6 auto-ubiquitination as well as NEMO/IKKγ substrate ubiquitination. Further, IL-1 triggered IKK/NF-κB signaling and induction of target genes is decreased by YOD1 overexpression and augmented after YOD1 depletion. Hence, our data define that YOD1 antagonizes TRAF6/p62-dependent IL-1 signaling to NF-κB.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Praveen Bawankar ◽  
Tina Lence ◽  
Chiara Paolantoni ◽  
Irmgard U. Haussmann ◽  
Migle Kazlauskiene ◽  
...  

AbstractN6-methyladenosine (m6A) is the most abundant internal modification on mRNA which influences most steps of mRNA metabolism and is involved in several biological functions. The E3 ubiquitin ligase Hakai was previously found in complex with components of the m6A methylation machinery in plants and mammalian cells but its precise function remained to be investigated. Here we show that Hakai is a conserved component of the methyltransferase complex in Drosophila and human cells. In Drosophila, its depletion results in reduced m6A levels and altered m6A-dependent functions including sex determination. We show that its ubiquitination domain is required for dimerization and interaction with other members of the m6A machinery, while its catalytic activity is dispensable. Finally, we demonstrate that the loss of Hakai destabilizes several subunits of the methyltransferase complex, resulting in impaired m6A deposition. Our work adds functional and molecular insights into the mechanism of the m6A mRNA writer complex.


2006 ◽  
Vol 26 (6) ◽  
pp. 2297-2308 ◽  
Author(s):  
Daniel Menendez ◽  
Alberto Inga ◽  
Michael A. Resnick

ABSTRACT Human tumor suppressor p53 is a sequence-specific master regulatory transcription factor that targets response elements (REs) in many genes. p53 missense mutations in the DNA-binding domain are often cancer associated. As shown with systems based on the yeast Saccharomyces cerevisiae, p53 mutants can alter the spectra and intensities of transactivation from individual REs. We address directly in human cells the relationship between changes in the p53 master regulatory network and biological outcomes. Expression of integrated, tightly regulated DNA-binding domain p53 mutants resulted in many patterns of apoptosis and survival following UV or ionizing radiation, or spontaneously. These patterns reflected changes in the spectra and activities of target genes, as demonstrated for P21, MDM2, BAX, and MSH2. Thus, as originally proposed for “master genes of diversity,” p53 mutations in human cells can differentially influence target gene transactivation, resulting in a variety of biological consequences which, in turn, might be expected to influence tumor development and therapeutic efficacy.


2019 ◽  
Vol 86 (4) ◽  
pp. 425-431 ◽  
Author(s):  
Zhi Chen ◽  
Jingpeng Zhou ◽  
Xiaolong Wang ◽  
Yang Zhang ◽  
Xubin Lu ◽  
...  

AbstractWe established a mastitis model using exogenous infection of the mammary gland of Chinese Holstein cows with Staphylococcus aureus and extracted total RNA from S. aureus-infected and healthy mammary quarters. Differential expression of genes due to mastitis was evaluated using Affymetrix technology and results revealed a total of 1230 differentially expressed mRNAs. A subset of affected genes was verified via Q-PCR and pathway analysis. In addition, Solexa high-throughput sequencing technology was used to analyze profiles of miRNA in infected and healthy quarters. These analyses revealed a total of 52 differentially expressed miRNAs. A subset of those results was verified via Q-PCR. Bioinformatics techniques were used to predict and analyze the correlations among differentially expressed miRNA and mRNA. Results revealed a total of 329 pairs of negatively associated miRNA/mRNA, with 31 upregulated pairs of mRNA and 298 downregulated pairs of mRNA. Differential expression of miR-15a and interleukin-1 receptor-associated kinase-like 2 (IRAK2), were evaluated by western blot and luciferase reporter assays. We conclude that miR-15a and miR-15a target genes (IRAK2) constitute potential miRNA–mRNA regulatory pairs for use as biomarkers to predict a mastitis response.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Brian G Peterson ◽  
Morgan L Glaser ◽  
Tom A Rapoport ◽  
Ryan D Baldridge

Misfolded proteins in the lumen of the endoplasmic reticulum (ER) are retrotranslocated into the cytosol and polyubiquitinated before being degraded by the proteasome. The multi-spanning ubiquitin ligase Hrd1 forms the retrotranslocation channel and associates with three other membrane proteins (Hrd3, Usa1, Der1) of poorly defined function. The Hrd1 channel is gated by autoubiquitination, but how Hrd1 escapes degradation by the proteasome and returns to its inactive ground state is unknown. Here, we show that autoubiquitination of Hrd1 is counteracted by Ubp1, a deubiquitinating enzyme that requires its N-terminal transmembrane segment for activity towards Hrd1. The Hrd1 partner Hrd3 serves as a brake for autoubiquitination, while Usa1 attenuates Ubp1’s deubiquitination activity through an inhibitory effect of its UBL domain. These results lead to a model in which the Hrd1 channel is regulated by cycles of autoubiquitination and deubiquitination, reactions that are modulated by the other components of the Hrd1 complex.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Jia He ◽  
Bin Xiao ◽  
Xiaoyan Li ◽  
Yongyin He ◽  
Linhai Li ◽  
...  

MicroRNAs have been broadly implicated in cancer, but precise functions and mechanisms in carcinogenesis vary among cancer types and in many cases remain poorly understood. Hepatocellular carcinoma (HCC) is among the most frequent and lethal cancers. The aim of the present study was to investigate the role of miR-486-5p in HCC and identify its specific target. MiR-486-5p was significantly downregulated in HCC tissues and cell lines compared with noncancerous tissues and, respectively, although expression level was not correlated with the degree of infiltration or tumor stage. However, miR-486-5p overexpression in HCC cells inhibited proliferation and migration as evidenced by CCK-8 cell counting, wound healing, and transwell assays, indicating that miR-486-5p is an HCC suppressor. We employed four miRNA databases to predict the target genes of miR-486-5p and verified retrieved genes using qPCR and western blotting. The E3 ubiquitin ligase CBL was significantly downregulated by miR-486-5p overexpression in HCC cell lines at both mRNA and protein level, and overexpression of CBL counteracted the inhibitory effects of miR-486-5p on HCC cell proliferation and migration. Moreover, CBL expression was negatively correlated with miR-486-5p expression in HCC tissues. Collectively, our results suggest that miR-486-5p may act as a tumor suppressor gene in HCC by downregulating CBL expression.


2019 ◽  
Vol 218 (3) ◽  
pp. 798-807 ◽  
Author(s):  
Victoria Riccio ◽  
Nicholas Demers ◽  
Rong Hua ◽  
Miluska Vissa ◽  
Derrick T. Cheng ◽  
...  

The regulation of organelle abundance is critical for cell function and survival; however, the mechanisms responsible are not fully understood. In this study, we characterize a role of the deubiquitinating enzyme USP30 in peroxisome maintenance. Peroxisomes are highly dynamic, changing in abundance in response to metabolic stress. In our recent study identifying the role of USP30 in mitophagy, we observed USP30 to be localized to punctate structures resembling peroxisomes. We report here that USP30, best known as a mitophagy regulator, is also necessary for regulating pexophagy, the selective autophagic degradation of peroxisomes. We find that overexpressing USP30 prevents pexophagy during amino acid starvation, and its depletion results in pexophagy induction under basal conditions. We demonstrate that USP30 prevents pexophagy by counteracting the action of the peroxisomal E3 ubiquitin ligase PEX2. Finally, we show that USP30 can rescue the peroxisome loss observed in some disease-causing peroxisome mutations, pointing to a potential therapeutic target.


2003 ◽  
Vol 23 (5) ◽  
pp. 589-598 ◽  
Author(s):  
Hyung Soo Han ◽  
Murat Karabiyikoglu ◽  
Stephen Kelly ◽  
Raymond A. Sobel ◽  
Midori A. Yenari

Nuclear factor-κB (NFκB) is a transcription factor that is activated after cerebral ischemia. NFκB activation leads to the expression of many inflammatory genes involved in the pathogenesis of stroke. The authors previously showed that mild hypothermia is protective even when cooling begins 2 h after stroke onset. In the present study, they examined the influence of hypothermia on NFκB activation. Rats underwent 2 h of transient middle cerebral artery occlusion. Brains were cooled to 33°C immediately after or 2 h after occlusion, and maintained for 2 h. After normothermic ischemia (brain temperature at 38°C), NFκB cytoplasmic expression, nuclear translocation, and binding activity were observed as early as 2 h in the ischemic hemisphere and persisted at 24 h. Hypothermia decreased NFκB translocation and binding activity but did not alter overall expression. Hypothermia also affected the levels of NFκB regulatory proteins by suppressing phosphorylation of NFκB's inhibitory protein (IκB-α) and IκB kinase (IKK-γ) and decreasing IKK activity, but did not alter overall IKK levels. Hypothermia suppressed the expression of two NFκB target genes: inducible nitric oxide synthase and TNF-α. These data suggest that the protective effect of hypothermia on cerebral injury is, in part, related to NFκB inhibition due to decreased activity of IKK.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Juan Zhang ◽  
Jiangang Song ◽  
Jin Xu ◽  
Xuemei Chen ◽  
Peihao Yin ◽  
...  

Early growth response- (Egr-) 1 is an upstream master switch in controlling inflammatory responses following myocardial ischemia-reperfusion (I/R). Activation of extracellular signal-regulated protein kinase-1 and kinase-2 (ERK1/2) signaling is known to upregulate Egr-1. ERK1/2 pathway has been previously shown to mediate the therapeutic action of electroacupucture (EA). Thus, we hypothesized that EA would reduce myocardial I/R injury and inflammatory responses through inhibiting Egr-1 expression via the ERK1/2 pathway. Mice were pretreated with EA, U0126, or combination of EA and U0126 and then underwent 1 h myocardial ischemia and 3 h reperfusion. We investigated that EA significantly attenuated the I/R-induced upregulation of both Egr-1 and phosporylated-ERK1/2 (p-ERK1/2), decreased myocardial inflammatory cytokines including tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β), and reduced the infarct size and the release of cardiac troponin I (cTnI). U0126 treatment also exhibited the same effect as EA on Egr-1 level and subsequent cardioprotective effects. There was no additive effect of cotreatment with EA and U0126 on the expression of Egr-1 and its downstream target genes (TNF-α, IL-1β) or serum cTnI level. Collectively, these observations suggested that EA attenuates myocardial I/R injury, possibly through inhibiting the ERK1/2-Egr-1 signaling pathway and reducing the release of proinflammatory cytokines.


2017 ◽  
Vol 114 (17) ◽  
pp. E3404-E3413 ◽  
Author(s):  
Chueh-Ling Kuo ◽  
Alfred Lewis Goldberg

In mammalian cells, the 26S proteasomes vary in composition. In addition to the standard 28 subunits in the 20S core particle and 19 subunits in each 19S regulatory particle, a small fraction (about 10–20% in our preparations) also contains the deubiquitinating enzyme Usp14/Ubp6, which regulates proteasome activity, and the ubiquitin ligase, Ube3c/Hul5, which enhances proteasomal processivity. When degradation of ubiquitinated proteins in cells was inhibited, levels of Usp14 and Ube3c on proteasomes increased within minutes. Conversely, when protein ubiquitination was prevented, or when purified proteasomes hydrolyzed the associated ubiquitin conjugates, Usp14 and Ube3c dissociated rapidly (unlike other 26S subunits), but the inhibitor ubiquitin aldehyde slowed their dissociation. Recombinant Usp14 associated with purified proteasomes preferentially if they contained ubiquitin conjugates. In cells or extracts, adding Usp14 inhibitors (IU-1 or ubiquitin aldehyde) enhanced Usp14 and Ube3c binding further. Thus, in the substrate- or the inhibitor-bound conformations, Usp14 showed higher affinity for proteasomes and surprisingly enhanced Ube3c binding. Moreover, adding ubiquitinated proteins to cell extracts stimulated proteasome binding of both enzymes. Thus, Usp14 and Ube3c cycle together on and off proteasomes, and the presence of ubiquitinated substrates promotes their association. This mechanism enables proteasome activity to adapt to the supply of substrates.


2001 ◽  
Vol 281 (2) ◽  
pp. H661-H668 ◽  
Author(s):  
Kristina Detmer ◽  
Zhongbiao Wang ◽  
Debra Warejcka ◽  
Sandra K. Leeper-Woodford ◽  
Walter H. Newman

Because inflammatory processes may promote the development of atherosclerosis, we examined the activation of cytokine genes in rat vascular smooth muscle cells in vitro after treatment with bacterial lipopolysaccharide (LPS). Interleukin-1 (IL-1), IL-6 and tumor necrosis factor-α (TNF-α) mRNA increased in response to LPS. Activation of nuclear factor-κB (NF-κB) presumably results in NF-κB binding to regulatory regions of target genes and activating transcription. We therefore compared the kinetics of NF-κB activation, cytokine message production, and TNF-α secretion. Maximum active NF-κB was found at 30 min after the addition of LPS and decreased thereafter. Increased IL-6 mRNA was detected at 30 min, increased TNF-α mRNA at 60 min, and increased IL-1 mRNA at 120 min. Secretion of TNF-α was dependent on LPS concentration and was first detected 120 min after LPS addition. Aspirin, which has been shown to inhibit NF-κB activation and cytokine secretion in other cell types, did not inhibit NF-κB activation or TNF-α secretion. However, aspirin reduced the amount of both TNF-α and IL-6 mRNA present 30 min after LPS addition by half ( P < 0.05).


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