Abstract 842: Messenger RNA Processing Body Participates In Cardiac Protection Induced By Heat Shock Preconditioning In Mouse Hearts

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Chang Yin ◽  
Rakesh C Kukreja
Keyword(s):  
Heat Shock ◽  
Messenger Rna ◽  
Micro Rna ◽  
Protective Mechanism ◽  
Body Formation ◽  
New Strategy ◽  
Body Components ◽  
Processing Body ◽  
Cardiac Preconditioning

mRNA Processing Body (P-Body) is a specialized cytoplasmic structure that functions as a major site for post-transcriptional and trnanslational repression. Target mRNA is guided into P-Body through base-pairing with its micro-RNA (miRNA), where they further bind to P-Body components such as GW182 and AGO2; thus get retained away from translation machinery or degraded. Our previous study detected an increase of a key component of P-Body, miRNA, in heat-shock (HS) protected hearts. To gain further insights into the protective mechanism, we hypothesized that the miRNA-associated protection is mediated through P-Body formation. This hypothesis was tested by measuring three key components of P-Body, i.e., miRNA (target seeker), GW182 (marker of P-Body, also called GW-Body) and AGO2 (mRNA catalytic enzyme). METHODS : ICR mice were either HS-preconditioned (15 min, 42°C, anal temperature) or kept at room temperature (controls). miRNA and proteins were extracted 2 hour after HS. miRNA induction was verified by RT-PCR. P-Body formation was evaluated by measuring the binding of GW182 and AGO2, using a combination of immunopricipitation and Western blotting techniques. To study the role of miRNA in P-Body formation, identical experiments were also repeated in mice treated with miRNA-1 inhibitor (antisense miRNA-1 with 2′-O-methyl base at every nucleotide). RESULTS : Compared to the control, HS-preconditioning significantly induced miRNA-1 (150 ± 11%, mean ± SEM), miRNA-21 (71 ± 10%) and miRNA-24 (68 ± 14%). GW182 (109 ± 16%) and AGO2 (50 ± 16%) were also increased in the HS-group. More importantly, there was an increase (39 ± 11%) in co-immunopricipitation between GW182 and AGO2 in the HS-group than in the control, indicating more binding of the two key P-Body components. However, this co-immunoprecipitation was significantly reduced (−68 ± 8%) in the mice treated with the miRNA-1 inhibitor after HS. CONCLUSION : The formation of P-Body following HS-preconditioning represents a novel protective pathway against ischemic injury. The pharmaceutical potential of P-Body formation may offer a new strategy in cardiac preconditioning.

scholarly journals The Ccr4a (CNOT6) and Ccr4b (CNOT6L) deadenylase subunits of the human Ccr4–Not complex contribute to the prevention of cell death and senescence

2011 ◽  
Vol 22 (6) ◽  
pp. 748-758 ◽  
Author(s):  
Saloni Mittal ◽  
Akhmed Aslam ◽  
Rachel Doidge ◽  
Rachel Medica ◽  
G. Sebastiaan Winkler
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Amino Terminal ◽  
Cycle Arrest ◽  
Gene Sets ◽  
Body Components ◽  
Processing Body ◽  
Lrr Domain

A key step in cytoplasmic mRNA degradation is the shortening of the poly(A) tail, which involves several deadenylase enzymes. Relatively little is known about the importance of these enzymes for the cellular physiology. Here we focused on the role of the highly similar Ccr4a (CNOT6) and Ccr4b (CNOT6L) deadenylase subunits of the Ccr4–Not complex. In addition to a role in cell proliferation, Ccr4a and Ccr4b play a role in cell survival, in contrast to the Caf1a (CNOT7) and Caf1b (CNOT8) deadenylase subunits or the CNOT1 and CNOT3 noncatalytic subunits of the Ccr4–Not complex. Underscoring the differential contributions of the deadenylase subunits, we found that knockdown of Caf1a/Caf1b or Ccr4a/Ccr4b differentially affects the formation of cytoplasmic foci by processing-body components. Furthermore, we demonstrated that the amino-terminal leucine-rich repeat (LRR) domain of Ccr4b influenced its subcellular localization but was not required for the deadenylase activity of Ccr4b. Moreover, overexpression of Ccr4b lacking the LRR domain interfered with cell cycle progression but not with cell viability. Finally, gene expression profiling indicated that distinct gene sets are regulated by Caf1a/Caf1b and Ccr4a/Ccr4b and identified Ccr4a/Ccr4b as a key regulator of insulin-like growth factor–binding protein 5, which mediates cell cycle arrest and senescence via a p53-dependent pathway.

scholarly journals Deadenylation is prerequisite for P-body formation and mRNA decay in mammalian cells

2008 ◽  
Vol 182 (1) ◽  
pp. 89-101 ◽  
Author(s):  
Dinghai Zheng ◽  
Nader Ezzeddine ◽  
Chyi-Ying A. Chen ◽  
Wenmiao Zhu ◽  
Xiangwei He ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Mammalian Cells ◽  
Mrna Decay ◽  
Protein Complexes ◽  
Major Step ◽  
Body Formation ◽  
P Bodies ◽  
Body Components ◽  
Selective Decay ◽  
Dynamic Interplay

Deadenylation is the major step triggering mammalian mRNA decay. One consequence of deadenylation is the formation of nontranslatable messenger RNA (mRNA) protein complexes (messenger ribonucleoproteins [mRNPs]). Nontranslatable mRNPs may accumulate in P-bodies, which contain factors involved in translation repression, decapping, and 5′-to-3′ degradation. We demonstrate that deadenylation is required for mammalian P-body formation and mRNA decay. We identify Pan2, Pan3, and Caf1 deadenylases as new P-body components and show that Pan3 helps recruit Pan2, Ccr4, and Caf1 to P-bodies. Pan3 knockdown causes a reduction of P-bodies and has differential effects on mRNA decay. Knocking down Caf1 or overexpressing a Caf1 catalytically inactive mutant impairs deadenylation and mRNA decay. P-bodies are not detected when deadenylation is blocked and are restored when the blockage is released. When deadenylation is impaired, P-body formation is not restorable, even when mRNAs exit the translating pool. These results support a dynamic interplay among deadenylation, mRNP remodeling, and P-body formation in selective decay of mammalian mRNA.

scholarly journals The RNA-binding protein Y14 inhibits mRNA decapping and modulates processing body formation

2013 ◽  
Vol 24 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Tzu-Wei Chuang ◽  
Wei-Lun Chang ◽  
Kuo-Ming Lee ◽  
Woan-Yuh Tarn
Keyword(s):  
Rna Binding ◽  
Mrna Degradation ◽  
Exon Junction Complex ◽  
Processing Bodies ◽  
Body Formation ◽  
Mrna Decapping ◽  
Mrna Metabolism ◽  
Processing Body

The exon-junction complex (EJC) deposited on a newly spliced mRNA plays an important role in subsequent mRNA metabolic events. Here we show that an EJC core heterodimer, Y14/Magoh, specifically associates with mRNA-degradation factors, including the mRNA-decapping complex and exoribonucleases, whereas another core factor, eIF4AIII/MLN51, does not. We also demonstrate that Y14 interacts directly with the decapping factor Dcp2 and the 5′ cap structure of mRNAs via different but overlapping domains and that Y14 inhibits the mRNA-decapping activity of Dcp2 in vitro. Accordingly, overexpression of Y14 prolongs the half-life of a reporter mRNA. Therefore Y14 may function independently of the EJC in preventing mRNA decapping and decay. Furthermore, we observe that depletion of Y14 disrupts the formation of processing bodies, whereas overexpression of a phosphomimetic Y14 considerably increases the number of processing bodies, perhaps by sequestering the mRNA-degradation factors. In conclusion, this report provides unprecedented evidence for a role of Y14 in regulating mRNA degradation and processing body formation and reinforces the influence of phosphorylation of Y14 on its activity in postsplicing mRNA metabolism.

scholarly journals InsP7is a small-molecule regulator of NUDT3-mediated mRNA decapping and processing-body dynamics

2020 ◽  
Vol 117 (32) ◽  
pp. 19245-19253 ◽  
Author(s):  
Soumyadip Sahu ◽  
Zhenzhen Wang ◽  
Xinfu Jiao ◽  
Chunfang Gu ◽  
Nikolaus Jork ◽  
...  
Keyword(s):  
Stress Responses ◽  
Messenger Rna ◽  
Control Process ◽  
Stem Cell Differentiation ◽  
Wild Type ◽  
Inositol Pyrophosphate ◽  
Body Dynamics ◽  
Processing Body ◽  
The Stability

Regulation of enzymatic 5′ decapping of messenger RNA (mRNA), which normally commits transcripts to their destruction, has the capacity to dynamically reshape the transcriptome. For example, protection from 5′ decapping promotes accumulation of mRNAs into processing (P) bodies—membraneless, biomolecular condensates. Such compartmentalization of mRNAs temporarily removes them from the translatable pool; these repressed transcripts are stabilized and stored until P-body dissolution permits transcript reentry into the cytosol. Here, we describe regulation of mRNA stability and P-body dynamics by the inositol pyrophosphate signaling molecule 5-InsP7(5-diphosphoinositol pentakisphosphate). First, we demonstrate 5-InsP7inhibits decapping by recombinant NUDT3 (Nudix [nucleoside diphosphate linked moiety X]-type hydrolase 3) in vitro. Next, in intact HEK293 and HCT116 cells, we monitored the stability of a cadre of NUDT3 mRNA substrates following CRISPR-Cas9 knockout ofPPIP5Ks(diphosphoinositol pentakisphosphate 5-kinases type 1 and 2, i.e.,PPIP5KKO), which elevates cellular 5-InsP7levels by two- to threefold (i.e., within the physiological rheostatic range). ThePPIP5KKO cells exhibited elevated levels of NUDT3 mRNA substrates and increased P-body abundance. Pharmacological and genetic attenuation of 5-InsP7synthesis in the KO background reverted both NUDT3 mRNA substrate levels and P-body counts to those of wild-type cells. Furthermore, liposomal delivery of a metabolically resistant 5-InsP7analog into wild-type cells elevated levels of NUDT3 mRNA substrates and raised P-body abundance. In the context that cellular 5-InsP7levels normally fluctuate in response to changes in the bioenergetic environment, regulation of mRNA structure by this inositol pyrophosphate represents an epitranscriptomic control process. The associated impact on P-body dynamics has relevance to regulation of stem cell differentiation, stress responses, and, potentially, amelioration of neurodegenerative diseases and aging.

scholarly journals DEAD-box helicases modulate dicing body formation in Arabidopsis

2021 ◽  
Vol 7 (18) ◽  
pp. eabc6266
Author(s):  
Qi Li ◽  
Ningkun Liu ◽  
Qing Liu ◽  
Xingguo Zheng ◽  
Lu Lu ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Turnip Mosaic Virus ◽  
Liquid Droplets ◽  
Phase Separations ◽  
Body Formation ◽  
Cellular Processes ◽  
Dead Box ◽  
Body Components ◽  
Liquid Phase Separations ◽  
Spatiotemporal Control

Eukaryotic cells contain numerous membraneless organelles that are made from liquid droplets of proteins and nucleic acids and that provide spatiotemporal control of various cellular processes. However, the molecular mechanisms underlying the formation and rapid stress-induced alterations of these organelles are relatively uncharacterized. Here, we investigated the roles of DEAD-box helicases in the formation and alteration of membraneless nuclear dicing bodies (D-bodies) in Arabidopsis thaliana. We uncovered that RNA helicase 6 (RH6), RH8, and RH12 are previously unidentified D-body components. These helicases interact with and promote the phase separation of SERRATE, a key component of D-bodies, and drive the formation of D-bodies through liquid-liquid phase separations (LLPSs). The accumulation of these helicases in the nuclei decreases upon Turnip mosaic virus infections, which couples with the decrease of D-bodies. Our results thus reveal the key roles of RH6, RH8, and RH12 in modulating D-body formation via LLPSs.

scholarly journals Tetrodotoxin: A New Strategy to Treat Visceral Pain?

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 496
Author(s):  
Ana Campos-Ríos ◽  
Lola Rueda-Ruzafa ◽  
Salvador Herrera-Pérez ◽  
Paula Rivas-Ramírez ◽  
José Antonio Lamas
Keyword(s):  
Action Potentials ◽  
Channel Blocker ◽  
Visceral Pain ◽  
Visceral Hypersensitivity ◽  
Afferent Neurons ◽  
Sodium Channel Blocker ◽  
Voltage Gated Sodium Channels ◽  
New Strategy ◽  
Specific Receptors

Visceral pain is one of the most common symptoms associated with functional gastrointestinal (GI) disorders. Although the origin of these symptoms has not been clearly defined, the implication of both the central and peripheral nervous systems in visceral hypersensitivity is well established. The role of several pathways in visceral nociception has been explored, as well as the influence of specific receptors on afferent neurons, such as voltage-gated sodium channels (VGSCs). VGSCs initiate action potentials and dysfunction of these channels has recently been associated with painful GI conditions. Current treatments for visceral pain generally involve opioid based drugs, ≠≠which are associated with important side-effects and a loss of effectiveness or tolerance. Hence, efforts have been intensified to find new, more effective and longer-lasting therapies. The implication of VGSCs in visceral hypersensitivity has drawn attention to tetrodotoxin (TTX), a relatively selective sodium channel blocker, as a possible and promising molecule to treat visceral pain and related diseases. As such, here we will review the latest information regarding this toxin that is relevant to the treatment of visceral pain and the possible advantages that it may offer relative to other treatments, alone or in combination.

scholarly journals Molecular Targets of Manganese-Induced Neurotoxicity: A Five-Year Update

2021 ◽  
Vol 22 (9) ◽  
pp. 4646
Author(s):  
Alexey A. Tinkov ◽  
Monica M. B. Paoliello ◽  
Aksana N. Mazilina ◽  
Anatoly V. Skalny ◽  
Airton C. Martins ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Mitochondrial Dysfunction ◽  
Synaptic Dysfunction ◽  
Future Research ◽  
Protective Mechanism ◽  
Autophagic Flux ◽  
Future Research Directions ◽  
The Impact

Understanding of the immediate mechanisms of Mn-induced neurotoxicity is rapidly evolving. We seek to provide a summary of recent findings in the field, with an emphasis to clarify existing gaps and future research directions. We provide, here, a brief review of pertinent discoveries related to Mn-induced neurotoxicity research from the last five years. Significant progress was achieved in understanding the role of Mn transporters, such as SLC39A14, SLC39A8, and SLC30A10, in the regulation of systemic and brain manganese handling. Genetic analysis identified multiple metabolic pathways that could be considered as Mn neurotoxicity targets, including oxidative stress, endoplasmic reticulum stress, apoptosis, neuroinflammation, cell signaling pathways, and interference with neurotransmitter metabolism, to name a few. Recent findings have also demonstrated the impact of Mn exposure on transcriptional regulation of these pathways. There is a significant role of autophagy as a protective mechanism against cytotoxic Mn neurotoxicity, yet also a role for Mn to induce autophagic flux itself and autophagic dysfunction under conditions of decreased Mn bioavailability. This ambivalent role may be at the crossroad of mitochondrial dysfunction, endoplasmic reticulum stress, and apoptosis. Yet very recent evidence suggests Mn can have toxic impacts below the no observed adverse effect of Mn-induced mitochondrial dysfunction. The impact of Mn exposure on supramolecular complexes SNARE and NLRP3 inflammasome greatly contributes to Mn-induced synaptic dysfunction and neuroinflammation, respectively. The aforementioned effects might be at least partially mediated by the impact of Mn on α-synuclein accumulation. In addition to Mn-induced synaptic dysfunction, impaired neurotransmission is shown to be mediated by the effects of Mn on neurotransmitter systems and their complex interplay. Although multiple novel mechanisms have been highlighted, additional studies are required to identify the critical targets of Mn-induced neurotoxicity.

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