scholarly journals p47 licenses activation of the immune deficiency pathway in the tick Ixodes scapularis

2018 ◽  
Vol 116 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Erin E. McClure Carroll ◽  
Xiaowei Wang ◽  
Dana K. Shaw ◽  
Anya J. O’Neal ◽  
Adela S. Oliva Chávez ◽  
...  
Keyword(s):  
Immune Deficiency ◽  
Ubiquitin Ligase ◽  
Ixodes Scapularis ◽  
Microbial Colonization ◽  
Signaling Cascades ◽  
Regulatory Subunit ◽  
Dependent Manner ◽  
Microbial Infection ◽  
Imd Pathway ◽  
Molecular Rheostat

The E3 ubiquitin ligase X-linked inhibitor of apoptosis (XIAP) acts as a molecular rheostat for the immune deficiency (IMD) pathway of the tick Ixodes scapularis. How XIAP activates the IMD pathway in response to microbial infection remains ill defined. Here, we identified the XIAP enzymatic substrate p47 as a positive regulator of the I. scapularis IMD network. XIAP polyubiquitylates p47 in a lysine 63-dependent manner and interacts with the p47 ubiquitin-like (UBX) module. p47 also binds to Kenny (IKKγ/NEMO), the regulatory subunit of the inhibitor of nuclear factor (NF)- κB kinase complex. Replacement of the amino acid lysine to arginine within the p47 linker region completely abrogated molecular interactions with Kenny. Furthermore, mitigation of p47 transcription levels through RNA interference in I. scapularis limited Kenny accumulation, reduced phosphorylation of IKKβ (IRD5), and impaired cleavage of the NF-κB molecule Relish. Accordingly, disruption of p47 expression increased microbial colonization by the Lyme disease spirochete Borrelia burgdorferi and the rickettsial agent Anaplasma phagocytophilum. Collectively, we highlight the importance of ticks for the elucidation of paradigms in arthropod immunology. Manipulating immune signaling cascades within I. scapularis may lead to innovative approaches to reducing the burden of tick-borne diseases.

scholarly journals Hyd ubiquitinates the NF-κB co-factor Akirin to activate an effective immune response in Drosophila

2018 ◽  
Author(s):  
Alexandre Cammarata-Mouchtouris ◽  
Xuan-Hung Nguyen ◽  
François Bonnay ◽  
Akira Goto ◽  
Amir Orian ◽  
...  
Keyword(s):  
Immune Response ◽  
Ubiquitin Ligase ◽  
Ex Vivo ◽  
Inflammatory Diseases ◽  
E3 Ubiquitin Ligase ◽  
Microbial Infection ◽  
Immune Effector ◽  
Imd Pathway ◽  
Immune Challenges ◽  
Subsequent Activation

One Sentence SummaryUpon microbial infection in Drosophila, the E3-ubiquitin ligase Hyd ubiquitinylates the NF-κB co-factor Akirin for its efficient binding to the NF-κB factor Relish and subsequent activation of immune effectors genes.ABSTRACTThe Drosophila IMD pathway is activated upon microbial challenge with Gramnegative bacteria to trigger the innate immune response. In order to decipher this NF-κB signaling pathway, we undertook an ex-vivo RNAi screen targeting specifically E3 ubiquitin ligases and identified the HECT E3 ubiquitin ligase Hyperplastic Discs “Hyd” as a new actor of the IMD pathway. We showed that Hyd targets the NF-κB cofactor of Akirin. The K63-polyubiquitination chains deposited by Hyd decorate Akirin for its efficient binding to the NF-κB transcription factor Relish. We showed that this Hyd-mediated interaction is critical to activate immune-induced genes that depend on both Relish and Akirin, but is dispensable for those that depend solely on Relish. Therefore Hyd is key in operating a NF-κB transcriptional selectivity downstream of the IMD pathway. Drosophila depleted for Hyd or Akirin failed to express the full set of immune-induced anti-microbial peptide coding genes and succumbed to immune challenges. We showed further that Ubr5, the mammalian homolog of Hyd, is also required downstream of the NF-κB pathway for the IL1β-mediated IL6 activation. This study links the action of a E3-ubiquitin ligase to the activation of immune effector genes, deepening our understanding of the involvement of ubiquitination in inflammation and identifying a potential target for the control of inflammatory diseases.

scholarly journals CRL4-DCAF12 Ubiquitin Ligase Controls MOV10 RNA Helicase during Spermatogenesis and T Cell Activation

2021 ◽  
Vol 22 (10) ◽  
pp. 5394
Author(s):  
Tomas Lidak ◽  
Nikol Baloghova ◽  
Vladimir Korinek ◽  
Radislav Sedlacek ◽  
Jana Balounova ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Ubiquitin Ligase ◽  
Cell Activation ◽  
Rna Helicase ◽  
Dependent Manner ◽  
Amino Acid Residues ◽  
Risc Complex ◽  
Wide Range

Multisubunit cullin-RING ubiquitin ligase 4 (CRL4)-DCAF12 recognizes the C-terminal degron containing acidic amino acid residues. However, its physiological roles and substrates are largely unknown. Purification of CRL4-DCAF12 complexes revealed a wide range of potential substrates, including MOV10, an “ancient” RNA-induced silencing complex (RISC) complex RNA helicase. We show that DCAF12 controls the MOV10 protein level via its C-terminal motif in a proteasome- and CRL-dependent manner. Next, we generated Dcaf12 knockout mice and demonstrated that the DCAF12-mediated degradation of MOV10 is conserved in mice and humans. Detailed analysis of Dcaf12-deficient mice revealed that their testes produce fewer mature sperms, phenotype accompanied by elevated MOV10 and imbalance in meiotic markers SCP3 and γ-H2AX. Additionally, the percentages of splenic CD4+ T and natural killer T (NKT) cell populations were significantly altered. In vitro, activated Dcaf12-deficient T cells displayed inappropriately stabilized MOV10 and increased levels of activated caspases. In summary, we identified MOV10 as a novel substrate of CRL4-DCAF12 and demonstrated the biological relevance of the DCAF12-MOV10 pathway in spermatogenesis and T cell activation.

scholarly journals Transition of yeast Can1 transporter to the inward-facing state unveils an α-arrestin target sequence promoting its ubiquitylation and endocytosis

2017 ◽  
Vol 28 (21) ◽  
pp. 2819-2832 ◽  
Author(s):  
Christos Gournas ◽  
Elie Saliba ◽  
Eva-Maria Krammer ◽  
Céline Barthelemy ◽  
Martine Prévost ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Control Mechanism ◽  
Molecular Level ◽  
Membrane Transporters ◽  
Signaling Cascades ◽  
Target Sequence ◽  
Target Region ◽  
Substrate Transport ◽  
Common Control ◽  
Amino Acid Permeases

Substrate-transport–elicited endocytosis is a common control mechanism of membrane transporters avoiding excess uptake of external compounds, though poorly understood at the molecular level. In yeast, endocytosis of transporters is triggered by their ubiquitylation mediated by the Rsp5 ubiquitin-ligase, recruited by α-arrestin–family adaptors. We here report that transport-elicited ubiquitylation of the arginine transporter Can1 is promoted by transition to an inward-facing state. This conformational change unveils a region of the N-terminal cytosolic tail targeted by the Art1 α-arrestin, which is activated via the TORC1 kinase complex upon arginine uptake. Can1 mutants altered in the arginine-binding site or a cytosolic tripeptide sequence permanently expose the α-arrestin–targeted region so that Art1 activation via TORC1 is sufficient to trigger their endocytosis. We also provide evidence that substrate-transport elicited endocytosis of other amino acid permeases similarly involves unmasking of a cytosolic Art1-target region coupled to activation of Art1 via TORC1. Our results unravel a mechanism likely involved in regulation of many other transporters by their own substrates. They also support the emerging view that transporter ubiquitylation relies on combinatorial interaction rules such that α-arrestins, stimulated via signaling cascades or in their basal state, recognize transporter regions permanently facing the cytosol or unveiled during transport.

scholarly journals Hect E3 ubiquitin ligase Tom1 controls Dia2 degradation during the cell cycle

2012 ◽  
Vol 23 (21) ◽  
pp. 4203-4211 ◽  
Author(s):  
Dong-Hwan Kim ◽  
Deanna M. Koepp
Keyword(s):  
Cell Cycle ◽  
Protein Degradation ◽  
Ubiquitin Ligase ◽  
E3 Ubiquitin Ligase ◽  
S Phase ◽  
Temperature Sensitive ◽  
Dependent Manner ◽  
Charged Residues ◽  
Phase Progression ◽  
Positively Charged

The ubiquitin proteasome system plays a pivotal role in controlling the cell cycle. The budding yeast F-box protein Dia2 is required for genomic stability and is targeted for ubiquitin-dependent degradation in a cell cycle–dependent manner, but the identity of the ubiquitination pathway is unknown. We demonstrate that the Hect domain E3 ubiquitin ligase Tom1 is required for Dia2 protein degradation. Deletion of DIA2 partially suppresses the temperature-sensitive phenotype of tom1 mutants. Tom1 is required for Dia2 ubiquitination and degradation during G1 and G2/M phases of the cell cycle, whereas the Dia2 protein is stabilized during S phase. We find that Tom1 binding to Dia2 is enhanced in G1 and reduced in S phase, suggesting a mechanism for this proteolytic switch. Tom1 recognizes specific, positively charged residues in a Dia2 degradation/NLS domain. Loss of these residues blocks Tom1-mediated turnover of Dia2 and causes a delay in G1–to–S phase progression. Deletion of DIA2 rescues a delay in the G1–to–S phase transition in the tom1Δ mutant. Together our results suggest that Tom1 targets Dia2 for degradation during the cell cycle by recognizing positively charged residues in the Dia2 degradation/NLS domain and that Dia2 protein degradation contributes to G1–to–S phase progression.

scholarly journals Complex effects of kinase localization revealed by compartment-specific regulation of protein kinase A activity

2021 ◽  
Author(s):  
Rebecca LaCroix ◽  
Benjamin Lin ◽  
Andre Levchenko
Keyword(s):  
Cell Migration ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase Activity ◽  
Single Cells ◽  
Regulatory Subunit ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Specific Regulation ◽  
Kinase A

SummaryKinase activity in signaling networks frequently depends on regulatory subunits that can both inhibit activity by interacting with the catalytic subunits and target the kinase to distinct molecular partners and subcellular compartments. Here, using a new synthetic molecular interaction system, we show that translocation of a regulatory subunit of the protein kinase A (PKA-R) to the plasma membrane has a paradoxical effect on the membrane kinase activity. It can both enhance it at lower translocation levels, even in the absence of signaling inputs, and inhibit it at higher translocation levels, suggesting its role as a linker that can both couple and decouple signaling processes in a concentration-dependent manner. We further demonstrate that superposition of gradients of PKA-R abundance across single cells can control the directionality of cell migration, reversing it at high enough input levels. Thus complex in vivo patterns of PKA-R localization can drive complex phenotypes, including cell migration.

scholarly journals Proteomic analysis identifies the E3 ubiquitin ligase Pdzrn3 as a regulatory target of Wnt5a-Ror signaling

2021 ◽  
Vol 118 (25) ◽  
pp. e2104944118
Author(s):  
Sara E. Konopelski Snavely ◽  
Michael W. Susman ◽  
Ryan C. Kunz ◽  
Jia Tan ◽  
Srisathya Srinivasan ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Large Scale ◽  
Glycogen Synthase ◽  
E3 Ubiquitin Ligase ◽  
Ubiquitin Proteasome System ◽  
Dependent Manner ◽  
Casein Kinase 1 ◽  
Downstream Signaling ◽  
Proteomic Screen ◽  
Responsive Element

Wnt5a-Ror signaling is a conserved pathway that regulates morphogenetic processes during vertebrate development [R. T. Moon et al., Development 119, 97–111 (1993); I. Oishi et al., Genes Cells 8, 645–654 (2003)], but its downstream signaling events remain poorly understood. Through a large-scale proteomic screen in mouse embryonic fibroblasts, we identified the E3 ubiquitin ligase Pdzrn3 as a regulatory target of the Wnt5a-Ror pathway. Upon pathway activation, Pdzrn3 is degraded in a β-catenin–independent, ubiquitin-proteasome system–dependent manner. We developed a flow cytometry-based reporter to monitor Pdzrn3 abundance and delineated a signaling cascade involving Frizzled, Dishevelled, Casein kinase 1, and Glycogen synthase kinase 3 that regulates Pdzrn3 stability. Epistatically, Pdzrn3 is regulated independently of Kif26b, another Wnt5a-Ror effector. Wnt5a-dependent degradation of Pdzrn3 requires phosphorylation of three conserved amino acids within its C-terminal LNX3H domain [M. Flynn, O. Saha, P. Young, BMC Evol. Biol. 11, 235 (2011)], which acts as a bona fide Wnt5a-responsive element. Importantly, this phospho-dependent degradation is essential for Wnt5a-Ror modulation of cell migration. Collectively, this work establishes a Wnt5a-Ror cell morphogenetic cascade involving Pdzrn3 phosphorylation and degradation.

scholarly journals GPR68 Contributes to Persistent Acidosis-Induced Activation of AGC Kinases and Tyrosine Phosphorylation in Organotypic Hippocampal Slices

2021 ◽  
Vol 15 ◽  
Author(s):  
Guokun Zhou ◽  
Xiang-ming Zha
Keyword(s):  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Neurological Diseases ◽  
Hippocampal Slices ◽  
Signaling Cascades ◽  
Dependent Manner ◽  
Cyclin Dependent Kinase ◽  
Ataxia Telangiectasia Mutated ◽  
Agc Kinases ◽  
Profiling Analysis

Persistent acidosis occurs in ischemia and multiple neurological diseases. In previous studies, acidic stimulation leads to rapid increase in intracellular calcium in neurons. However, it remains largely unclear how a prolonged acidosis alters neuronal signaling. In our previous study, we found that GPR68-mediated PKC activities are protective against acidosis-induced injury in cortical slices. Here, we first asked whether the same principle holds true in organotypic hippocampal slices. Our data showed that 1-h pH 6 induced PKC phosphorylation in a GPR68-dependent manner. Go6983, a PKC inhibitor worsened acidosis-induced neuronal injury in wild type (WT) but had no effect in GPR68−/− slices. Next, to gain greater insights into acid signaling in brain tissue, we treated organotypic hippocampal slices with pH 6 for 1-h and performed a kinome profiling analysis by Western blot. Acidosis had little effect on cyclin-dependent kinase (CDK) or casein kinase 2 activity, two members of the CMGC family, or Ataxia telangiectasia mutated (ATM)/ATM and RAD3-related (ATR) activity, but reduced the phosphorylation of MAPK/CDK substrates. In contrast, acidosis induced the activation of CaMKIIα, PKA, and Akt. Besides these serine/threonine kinases, acidosis also induced tyrosine phosphorylation. Since GPR68 is widely expressed in brain neurons, we asked whether GPR68 contributes to acidosis-induced signaling. Deleting GPR68 had no effect on acidosis-induced CaMKII phosphorylation, attenuated that of phospho-Akt and phospho-PKA substrates, while abolishing acidosis-induced tyrosine phosphorylation. These data demonstrate that prolonged acidosis activates a network of signaling cascades, mediated by AGC kinases, CaMKII, and tyrosine kinases. GPR68 is the primary mediator for acidosis-induced activation of PKC and tyrosine phosphorylation, while both GPR68-dependent and -independent mechanisms contribute to the activation of PKA and Akt.

scholarly journals Protein polyglutamylation catalyzed by the bacterial calmodulin-dependent pseudokinase SidJ

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Alan Sulpizio ◽  
Marena E Minelli ◽  
Min Wan ◽  
Paul D Burrowes ◽  
Xiaochun Wu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Ubiquitin Ligase ◽  
Legionella Pneumophila ◽  
Kinase Activity ◽  
Effector Protein ◽  
Dependent Manner ◽  
Biochemical Analyses ◽  
Human And Mouse

Pseudokinases are considered to be the inactive counterparts of conventional protein kinases and comprise approximately 10% of the human and mouse kinomes. Here, we report the crystal structure of the Legionella pneumophila effector protein, SidJ, in complex with the eukaryotic Ca2+-binding regulator, calmodulin (CaM). The structure reveals that SidJ contains a protein kinase-like fold domain, which retains a majority of the characteristic kinase catalytic motifs. However, SidJ fails to demonstrate kinase activity. Instead, mass spectrometry and in vitro biochemical analyses demonstrate that SidJ modifies another Legionella effector SdeA, an unconventional phosphoribosyl ubiquitin ligase, by adding glutamate molecules to a specific residue of SdeA in a CaM-dependent manner. Furthermore, we show that SidJ-mediated polyglutamylation suppresses the ADP-ribosylation activity. Our work further implies that some pseudokinases may possess ATP-dependent activities other than conventional phosphorylation.

scholarly journals ASF1B Promotes Oncogenesis in Lung Adenocarcinoma and Other Cancer Types

2021 ◽  
Vol 11 ◽  
Author(s):  
Wencheng Zhang ◽  
Zhouyong Gao ◽  
Mingxiu Guan ◽  
Ning Liu ◽  
Fanjie Meng ◽  
...  
Keyword(s):  
Lung Adenocarcinoma ◽  
Immune Cell ◽  
Gene Set Enrichment Analysis ◽  
The Cancer Genome Atlas ◽  
Tumor Promoter ◽  
Regulatory Subunit ◽  
Cell Cycle Distribution ◽  
Cancer Type ◽  
Dependent Manner ◽  
Cancer Types

Anti-silencing function 1B histone chaperone (ASF1B) is known to be an important modulator of oncogenic processes, yet its role in lung adenocarcinoma (LUAD) remains to be defined. In this study, an integrated assessment of The Cancer Genome Atlas (TCGA) and genotype-tissue expression (GTEx) datasets revealed the overexpression of ASF1B in all analyzed cancer types other than LAML. Genetic, epigenetic, microsatellite instability (MSI), and tumor mutational burden (TMB) analysis showed that ASF1B was regulated by single or multiple factors. Kaplan-Meier survival curves suggested that elevated ASF1B expression was associated with better or worse survival in a cancer type-dependent manner. The CIBERSORT algorithm was used to evaluate immune microenvironment composition, and distinct correlations between ASF1B expression and immune cell infiltration were evident when comparing tumor and normal tissue samples. Gene set enrichment analysis (GSEA) indicated that ASF1B was associated with proliferation- and immunity-related pathways. Knocking down ASF1B impaired the proliferation, affected cell cycle distribution, and induced cell apoptosis in LUAD cell lines. In contrast, ASF1B overexpression had no impact on the malignant characteristics of LUAD cells. At the mechanistic level, ASF1B served as an indirect regulator of DNA Polymerase Epsilon 3, Accessory Subunit (POLE3), CDC28 protein kinase regulatory subunit 1(CKS1B), Dihydrofolate reductase (DHFR), as established through proteomic profiling and Immunoprecipitation-Mass Spectrometry (IP-MS) analyses. Overall, these data suggested that ASF1B serves as a tumor promoter and potential target for cancer therapy and provided us with clues to better understand the importance of ASF1B in many types of cancer.

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