scholarly journals RNA processing machineries in Archaea: the 5′-3′ exoribonuclease aRNase J of the β-CASP family is engaged specifically with the helicase ASH-Ski2 and the 3′-5′ exoribonucleolytic RNA exosome machinery

2020 ◽  
Vol 48 (7) ◽  
pp. 3832-3847 ◽  
Author(s):  
Duy Khanh Phung ◽  
Clarisse Etienne ◽  
Manon Batista ◽  
Petra Langendijk-Genevaux ◽  
Yann Moalic ◽  
...  
Keyword(s):  
Rna Processing ◽  
Cell Extract ◽  
Rna Helicases ◽  
Rna Surveillance ◽  
Protein Protein Interaction ◽  
Rna Exosome ◽  
Whole Cell Extract

Abstract A network of RNA helicases, endoribonucleases and exoribonucleases regulates the quantity and quality of cellular RNAs. To date, mechanistic studies focussed on bacterial and eukaryal systems due to the challenge of identifying the main drivers of RNA decay and processing in Archaea. Here, our data support that aRNase J, a 5′-3′ exoribonuclease of the β-CASP family conserved in Euryarchaeota, engages specifically with a Ski2-like helicase and the RNA exosome to potentially exert control over RNA surveillance, at the vicinity of the ribosome. Proteomic landscapes and direct protein–protein interaction analyses, strengthened by comprehensive phylogenomic studies demonstrated that aRNase J interplay with ASH-Ski2 and a cap exosome subunit. Finally, Thermococcus barophilus whole-cell extract fractionation experiments provide evidences that an aRNase J/ASH-Ski2 complex might exist in vivo and hint at an association of aRNase J with the ribosome that is emphasised in absence of ASH-Ski2. Whilst aRNase J homologues are found among bacteria, the RNA exosome and the Ski2-like RNA helicase have eukaryotic homologues, underlining the mosaic aspect of archaeal RNA machines. Altogether, these results suggest a fundamental role of β-CASP RNase/helicase complex in archaeal RNA metabolism.

scholarly journals RNA processing machineries in Archaea: the 5’-3’ exoribonuclease aRNase J of the β-CASP family is engaged specifically with the helicase ASH-Ski2 and the 3’-5’ exoribonucleolytic RNA exosome machinery

2019 ◽  
Author(s):  
Duy Khanh Phung ◽  
Clarisse Etienne ◽  
Manon Batista ◽  
Petra Langendijk-Genevaux ◽  
Yann Moalic ◽  
...  
Keyword(s):  
Rna Processing ◽  
Cell Extract ◽  
Rna Helicases ◽  
Rna Surveillance ◽  
Protein Protein Interaction ◽  
Rna Exosome ◽  
First Time

ABSTRACTA network of RNA helicases, endoribonucleases, and exoribonucleases regulates the quantity and quality of cellular RNAs. To date, mechanistic studies focused on bacterial and eukaryal systems due to the challenge of identifying the main drivers of RNA decay and processing in Archaea. Here, our data support that aRNase J, a 5’-3’ exoribonuclease of the β-CASP family conserved in Euryarchaea, engages specifically with a Ski2-like helicase and the RNA exosome to potentially exert control over RNA surveillance, and that this occurs in the vicinity of the ribosome. Proteomic landscapes and direct protein-protein interaction analyses demonstrated that aRNase J interplay with ASH-Ski2 and the Csl4 cap exosome subunit. These in vitro data are strengthened by our phylogenomic studies showing a taxonomic co-distribution of aRNase J and ASH-Ski2 among the archaeal phylogeny. Finally, our T. barophilus whole-cell extract fractionation experiments provide evidences that an aRNase J/ASH-Ski2 complex might exist in vivo and hint at an association of aRNase J with the ribosome or polysomes that is stressed in absence of ASH-Ski2. While aRNase J homologues are found among bacteria, the RNA exosome and the Ski2-like RNA helicase have eukaryotic homologues, underlining the mosaic aspect of archaeal RNA machines. Altogether, these results suggest, for the first time, a fundamental role of β-CASP RNase/helicase complex in archaeal RNA metabolism. Finally, our results position aRNase J at the junction of RNA surveillance and translation processes, thus opening new perspectives and evolutionary scenario on RNA processing players in Archaea.

scholarly journals Antioxidant Therapy in Graves’ Orbitopathy

2020 ◽  
Vol 11 ◽  
Author(s):  
Giulia Lanzolla ◽  
Claudio Marcocci ◽  
Michele Marinò
Keyword(s):  
Ros Generation ◽  
Related Condition ◽  
Orbital Radiotherapy ◽  
Antioxidant Agents ◽  
Graves Orbitopathy ◽  
High Doses

The balance of the cell redox state is a key point for the maintenance of cellular homeostasis. Increased reactive oxygen species (ROS) generation leads to oxidative damage of tissues, which is involved in the development of several diseases, including autoimmune diseases. Graves’ Orbitopathy (GO) is a disfiguring autoimmune-related condition associated with Graves’ Disease (GD). Patients with active, moderate-to-severe GO, are generally treated with high doses intravenous glucocorticoids (ivGCs) and/or orbital radiotherapy. On the contrary, up to recently, local ointments were the treatment most frequently offered to patients with mild GO, because the risks related to ivGCs does not justify the relatively poor benefits expected in mild GO. However, a medical treatment for these patients is heavily wanted, considering that GO can progress into more severe forms and also patients with mild GO complain with an impairment in their quality of life. Thus, based on the role of oxidative stress in the pathogenesis of GO, a therapy with antioxidant agents has been proposed and a number of studies have been performed, both in vitro and in vivo, which is reviewed here.

scholarly journals Targeting Wnt/β-Catenin Pathway for Developing Therapies for Hair Loss

2020 ◽  
Vol 21 (14) ◽  
pp. 4915 ◽  
Author(s):  
Bu Young Choi
Keyword(s):  
Hair Loss ◽  
Hair Growth ◽  
In Vivo Studies ◽  
Intracellular Targets ◽  
Remarkable Progress ◽  
Made In

Persistent hair loss is a major cause of psychological distress and compromised quality of life in millions of people worldwide. Remarkable progress has been made in understanding the molecular basis of hair loss and identifying valid intracellular targets for designing effective therapies for hair loss treatment. Whereas a variety of growth factors and signaling pathways have been implicated in hair cycling process, the activation of Wnt/β-catenin signaling plays a central role in hair follicle regeneration. Several plant-derived chemicals have been reported to promote hair growth by activating Wnt/β-catenin signaling in various in vitro and in vivo studies. This mini-review sheds light on the role of Wnt/β-catenin in promoting hair growth and the current progress in designing hair loss therapies by targeting this signaling pathway.

scholarly journals Mid-Gestation lethality of Atxn2l-Ablated Mice

2020 ◽  
Vol 21 (14) ◽  
pp. 5124 ◽  
Author(s):  
Jana Key ◽  
Patrick N. Harter ◽  
Nesli-Ece Sen ◽  
Elise Gradhand ◽  
Georg Auburger ◽  
...  
Keyword(s):  
Giant Cells ◽  
Neural Cells ◽  
Rna Surveillance ◽  
Extended Lifespan ◽  
Ataxin 2 ◽  
Locomotor Deficits ◽  
Lateral Sclerosis

Depletion of yeast/fly Ataxin-2 rescues TDP-43 overexpression toxicity. In mouse models of Amyotrophic Lateral Sclerosis via TDP-43 overexpression, depletion of its ortholog ATXN2 mitigated motor neuron degeneration and extended lifespan from 25 days to >300 days. There is another ortholog in mammals, named ATXN2L (Ataxin-2-like), which is almost uncharacterized but also functions in RNA surveillance at stress granules. We generated mice with Crispr/Cas9-mediated deletion of Atxn2l exons 5-8, studying homozygotes prenatally and heterozygotes during aging. Our novel findings indicate that ATXN2L absence triggers mid-gestational embryonic lethality, affecting female animals more strongly. Weight and development stages of homozygous mutants were reduced. Placenta phenotypes were not apparent, but brain histology showed lamination defects and apoptosis. Aged heterozygotes showed no locomotor deficits or weight loss over 12 months. Null mutants in vivo displayed compensatory efforts to maximize Atxn2l expression, which were prevented upon nutrient abundance in vitro. Mouse embryonal fibroblast cells revealed more multinucleated giant cells upon ATXN2L deficiency. In addition, in human neural cells, transcript levels of ATXN2L were induced upon starvation and glucose and amino acids exposure, but this induction was partially prevented by serum or low cholesterol administration. Neither ATXN2L depletion triggered dysregulation of ATXN2, nor a converse effect was observed. Overall, this essential role of ATXN2L for embryogenesis raises questions about its role in neurodegenerative diseases and neuroprotective therapies.

scholarly journals A Conserved Residue in the Yeast Bem1p SH3 Domain Maintains the High Level of Binding Specificity Required for Function

2011 ◽  
Vol 286 (22) ◽  
pp. 19470-19477 ◽  
Author(s):  
Maryna Gorelik ◽  
Karen Stanger ◽  
Alan R. Davidson
Keyword(s):  
Sequence Similarity ◽  
Consensus Sequence ◽  
Binding Specificity ◽  
Biologically Relevant ◽  
Protein Protein Interaction ◽  
Nonspecific Interactions ◽  
High Level ◽  
Conserved Residue

The yeast Bem1p SH3b and Nbp2p SH3 domains are unusual because they bind to peptides containing the same consensus sequence, yet they perform different functions and display low sequence similarity. In this work, by analyzing the interactions of these domains with six biologically relevant peptides containing the consensus sequence, they are shown to possess finely tuned and distinct binding specificities. We also identify a residue in the Bem1p SH3b domain that inhibits binding, yet is highly conserved for the purpose of preventing nonspecific interactions. Substitution of this residue results in a marked reduction of in vivo function that is caused by titration of the domain away from its proper targets through nonspecific interactions with other proteins. This work provides a clear illustration of the importance of intrinsic binding specificity for the function of protein-protein interaction modules, and the key role of “negative” interactions in determining the specificity of a domain.

Anchoring of FLT3 in the endoplasmic reticulum alters signaling quality

Blood ◽  
2009 ◽  
Vol 113 (15) ◽  
pp. 3568-3576 ◽  
Author(s):  
Dirk Schmidt-Arras ◽  
Sylvia-Annette Böhmer ◽  
Sina Koch ◽  
Jörg P. Müller ◽  
Lutz Blei ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Transformation ◽  
Intracellular Location ◽  
Er Retention ◽  
Transforming Activity ◽  
Signaling Quality

Abstract The mechanism of cell transformation by Fms-like tyrosine kinase 3 (FLT3) in acute myeloid leukemia (AML) is incompletely understood. The most prevalent activated mutant FLT3 ITD exhibits an altered signaling quality, including strong activation of the STAT5 transcription factor. FLT3 ITD has also been found partially retained as a high-mannose precursor in an intracellular compartment. To analyze the role of intracellular retention of FLT3 for transformation, we have generated FLT3 versions that are anchored in the perinuclear endoplasmic reticulum (ER) by appending an ER retention sequence containing a RRR (R3) motif. ER retention of R3, but not of corresponding A3 FLT3 versions, is shown by biochemical, fluorescence-activated cell sorting, and immunocytochemical analyses. ER anchoring reduced global autophosphorylation and diminished constitutive activation of ERK1/2 and AKT of the constitutively active FLT3 versions. ER anchoring was, however, associated with elevated signaling to STAT3. Transforming activity of the FLT3 D835Y mutant was suppressed by ER anchoring. In contrast, ER-anchored FLT3 ITD retained STAT5-activating capacity and was transforming in vitro and in vivo. The findings highlight another aspect of the different signaling quality of FLT3 ITD: It can transform cells from an intracellular location.

scholarly journals Human Papillomavirus E2 Protein: Linking Replication, Transcription, and RNA Processing

2016 ◽  
Vol 90 (19) ◽  
pp. 8384-8388 ◽  
Author(s):  
Sheila V. Graham
Keyword(s):  
Human Papillomavirus ◽  
Life Cycle ◽  
Rna Processing ◽  
Nucleic Acid Binding ◽  
Viral Production ◽  
Interaction Domain ◽  
E2 Protein ◽  
Protein Protein Interaction ◽  
Cellular Environment

The human papillomavirus (HPV) life cycle is tightly linked to differentiation of the infected epithelium. This means that viral proteins must exert control over epithelial gene expression in order to optimize viral production. The HPV E2 protein controls replication, transcription, and viral genome partitioning during the viral infectious life cycle. It consists of a nucleic acid-binding domain and a protein-protein interaction domain separated by a flexible serine and arginine-rich hinge region. Over the last few years, mounting evidence has uncovered an important new role for E2 in viral and cellular RNA processing. This Gem discusses the role of E2 in controlling the epithelial cellular environment and how E2 might act to coordinate late events in the viral replication cycle.

scholarly journals A novel role of farnesylation in targeting a mitotic checkpoint protein, human Spindly, to kinetochores

2015 ◽  
Vol 208 (7) ◽  
pp. 881-896 ◽  
Author(s):  
Devinderjit K. Moudgil ◽  
Nathan Westcott ◽  
Jakub K. Famulski ◽  
Kinjal Patel ◽  
Dawn Macdonald ◽  
...  
Keyword(s):  
Mitotic Checkpoint ◽  
Cysteine Residue ◽  
Farnesyl Transferase ◽  
Checkpoint Protein ◽  
Protein Protein Interaction ◽  
Domain Mapping ◽  
Mitotic Checkpoint Protein ◽  
Dynactin Complex

Kinetochore (KT) localization of mitotic checkpoint proteins is essential for their function during mitosis. hSpindly KT localization is dependent on the RZZ complex and hSpindly recruits the dynein–dynactin complex to KTs during mitosis, but the mechanism of hSpindly KT recruitment is unknown. Through domain-mapping studies we characterized the KT localization domain of hSpindly and discovered it undergoes farnesylation at the C-terminal cysteine residue. The N-terminal 293 residues of hSpindly are dispensable for its KT localization. Inhibition of farnesylation using a farnesyl transferase inhibitor (FTI) abrogated hSpindly KT localization without affecting RZZ complex, CENP-E, and CENP-F KT localization. We showed that hSpindly is farnesylated in vivo and farnesylation is essential for its interaction with the RZZ complex and hence KT localization. FTI treatment and hSpindly knockdown displayed the same mitotic phenotypes, indicating that hSpindly is a key FTI target in mitosis. Our data show a novel role of lipidation in targeting a checkpoint protein to KTs through protein–protein interaction.

scholarly journals The block to transcription elongation at the minute virus of mice attenuator is regulated by cellular elongation factors.

1991 ◽  
Vol 11 (7) ◽  
pp. 3515-3521 ◽  
Author(s):  
A Krauskopf ◽  
E Bengal ◽  
Y Aloni
Keyword(s):  
Rna Polymerase Ii ◽  
Transcription Elongation ◽  
Cell Extract ◽  
Elongation Factors ◽  
Minute Virus Of Mice ◽  
Whole Cell ◽  
Minute Virus ◽  
Whole Cell Extract

We have previously reported that both in vivo and in vitro, RNA polymerase II pauses or prematurely terminates transcription at a specific attenuation site located 142 to 147 nucleotides downstream from the P4 promoter of minute virus of mice (MVM). In this report, we show that an in vitro block to transcription elongation in HeLa whole-cell extract occurs at elevated KCl concentrations (0.2 to 1.5 M) but not at the standard KCl concentration (50 mM). Briefly initiated transcription complexes, devoid of dissociated elongation factors by passage through a Sephacryl S-1000 column at 0.3 M KCl, were allowed to elongate the briefly initiated nascent RNA, and a block to transcription elongation at the attenuation site was observed independently of the KCl concentration at the time of elongation. Moreover, the block to elongation was overcome by the addition, during elongation, to the column of purified complexes of whole-cell extract from EA cells but not from MVM-infected EA cells or HeLa cells. The general transcription factors IIF and IIX were also shown to alleviate this block to transcription elongation. On the basis of these results, we suggest that the block to elongation at the MVM attenuation site observed late in MVM infection results, at least in part, from the inactivation of the general transcription elongation factors.

scholarly journals The RNA helicase Dhx15 mediates Wnt-induced antimicrobial protein expression in Paneth cells

2021 ◽  
Vol 118 (4) ◽  
pp. e2017432118
Author(s):  
Yalong Wang ◽  
Kaixin He ◽  
Baifa Sheng ◽  
Xuqiu Lei ◽  
Wanyin Tao ◽  
...  
Keyword(s):  
Rna Splicing ◽  
Intestinal Inflammation ◽  
Paneth Cell ◽  
Enteric Bacteria ◽  
Paneth Cells ◽  
Antimicrobial Protein ◽  
Rna Helicases

RNA helicases play roles in various essential biological processes such as RNA splicing and editing. Recent in vitro studies show that RNA helicases are involved in immune responses toward viruses, serving as viral RNA sensors or immune signaling adaptors. However, there is still a lack of in vivo data to support the tissue- or cell-specific function of RNA helicases owing to the lethality of mice with complete knockout of RNA helicases; further, there is a lack of evidence about the antibacterial role of helicases. Here, we investigated the in vivo role of Dhx15 in intestinal antibacterial responses by generating mice that were intestinal epithelial cell (IEC)-specific deficient for Dhx15 (Dhx15 f/f Villin1-cre, Dhx15ΔIEC). These mice are susceptible to infection with enteric bacteria Citrobacter rodentium (C. rod), owing to impaired α-defensin production by Paneth cells. Moreover, mice with Paneth cell-specific depletion of Dhx15 (Dhx15 f/f Defensinα6-cre, Dhx15ΔPaneth) are more susceptible to DSS (dextran sodium sulfate)-induced colitis, which phenocopy Dhx15ΔIEC mice, due to the dysbiosis of the intestinal microbiota. In humans, reduced protein levels of Dhx15 are found in ulcerative colitis (UC) patients. Taken together, our findings identify a key regulator of Wnt-induced α-defensins in Paneth cells and offer insights into its role in the antimicrobial response as well as intestinal inflammation.

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