scholarly journals The Role of Molecular Microtubule Motors and the Microtubule Cytoskeleton in Stress Granule Dynamics

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Kristen M. Bartoli ◽  
Darryl L. Bishop ◽  
William S. Saunders
Keyword(s):  
Current Literature ◽  
Motor Proteins ◽  
Stress Granules ◽  
Stress Granule ◽  
Microtubule Cytoskeleton ◽  
Microtubule Motors ◽  
Key Players ◽  
Underlying Mechanisms ◽  
Main Components

Stress granules (SGs) are cytoplasmic foci that appear in cells exposed to stress-induced translational inhibition. SGs function as a triage center, where mRNAs are sorted for storage, degradation, and translation reinitiation. The underlying mechanisms of SGs dynamics are still being characterized, although many key players have been identified. The main components of SGs are stalled 48S preinitiation complexes. To date, many other proteins have also been found to localize in SGs and are hypothesized to function in SG dynamics. Most recently, the microtubule cytoskeleton and associated motor proteins have been demonstrated to function in SG dynamics. In this paper, we will discuss current literature examining the function of microtubules and the molecular microtubule motors in SG assembly, coalescence, movement, composition, organization, and disassembly.

scholarly journals Translationally Repressed mRNA Transiently Cycles through Stress Granules during Stress

2008 ◽  
Vol 19 (10) ◽  
pp. 4469-4479 ◽  
Author(s):  
Stephanie Mollet ◽  
Nicolas Cougot ◽  
Ania Wilczynska ◽  
François Dautry ◽  
Michel Kress ◽  
...  
Keyword(s):  
Residence Time ◽  
Kinetic Data ◽  
Stress Granules ◽  
Stress Relief ◽  
Mrna Degradation ◽  
Stress Granule ◽  
Storage Site ◽  
Direct Role ◽  
Close Proximity

In mammals, repression of translation during stress is associated with the assembly of stress granules in the cytoplasm, which contain a fraction of arrested mRNA and have been proposed to play a role in their storage. Because physical contacts are seen with GW bodies, which contain the mRNA degradation machinery, stress granules could also target arrested mRNA to degradation. Here we show that contacts between stress granules and GW bodies appear during stress-granule assembly and not after a movement of the two preassembled structures. Despite this close proximity, the GW body proteins, which in some conditions relocalize in stress granules, come from cytosol rather than from adjacent GW bodies. It was previously reported that several proteins actively traffic in and out of stress granules. Here we investigated the behavior of mRNAs. Their residence time in stress granules is brief, on the order of a minute, although stress granules persist over a few hours after stress relief. This short transit reflects rapid return to cytosol, rather than transfer to GW bodies for degradation. Accordingly, most arrested mRNAs are located outside stress granules. Overall, these kinetic data do not support a direct role of stress granules neither as storage site nor as intermediate location before degradation.

The role of microtubules in transport between the endoplasmic reticulum and Golgi apparatus in mammalian cells.

2005 ◽  
Vol 72 ◽  
pp. 1-13 ◽  
Author(s):  
Krysten J. Palmer ◽  
Peter Watson ◽  
David J. Stephens
Keyword(s):  
Endoplasmic Reticulum ◽  
Mammalian Cells ◽  
Secretory Pathway ◽  
Motor Proteins ◽  
Microtubule Cytoskeleton ◽  
Early Secretory Pathway ◽  
Golgi Transport ◽  
Intracellular Compartments ◽  
Retrograde Traffic

The organization of intracellular compartments and the transfer of components between them are central to the correct functioning of mammalian cells. Proteins and lipids are transferred between compartments by the formation, movement and subsequent specific fusion of transport intermediates. These vesicles and membrane clusters must be coupled to the cytoskeleton and to motor proteins that drive motility. Anterograde ER (endoplasmic reticulum)-to-Golgi transport, and the converse step of retrograde traffic from the Golgi to the ER, are now known to involve coupling of membranes to the microtubule cytoskeleton. Here we shall discuss our current understanding of the mechanisms that link membrane traffic in the early secretory pathway to the microtubule cytoskeleton in mammalian cells. Recent data have also provided molecular detail of functional co-ordination of motor proteins to specify directionality, as well as mechanisms for regulating motor activity by protein phosphorylation.

scholarly journals Stress Granule Formation Attenuates RACK1-Mediated Apoptotic Cell Death Induced by Morusin

2020 ◽  
Vol 21 (15) ◽  
pp. 5360
Author(s):  
Ye-Jin Park ◽  
Dong Wook Choi ◽  
Sang Woo Cho ◽  
Jaeseok Han ◽  
Siyoung Yang ◽  
...  
Keyword(s):  
Cell Death ◽  
Apoptotic Cell ◽  
Stress Granules ◽  
Protective Role ◽  
Stress Granule ◽  
Protein Kinase R ◽  
Granule Formation ◽  
Protective Function ◽  
Eif2α Phosphorylation

Stress granules are membraneless organelles composed of numerous components including ribonucleoproteins. The stress granules are characterized by a dynamic complex assembly in response to various environmental stressors, which has been implicated in the coordinated regulation of diverse biological pathways, to exert a protective role against stress-induced cell death. Here, we show that stress granule formation is induced by morusin, a novel phytochemical displaying antitumor capacity through barely known mechanisms. Morusin-mediated induction of stress granules requires activation of protein kinase R (PKR) and subsequent eIF2α phosphorylation. Notably, genetic inactivation of stress granule formation mediated by G3BP1 knockout sensitized cancer cells to morusin treatment. This protective function against morusin-mediated cell death can be attributed at least in part to the sequestration of receptors for activated C kinase-1 (RACK1) within the stress granules, which reduces caspase-3 activation. Collectively, our study provides biochemical evidence for the role of stress granules in suppressing the antitumor capacity of morusin, proposing that morusin treatment, together with pharmacological inhibition of stress granules, could be an efficient strategy for targeting cancer.

scholarly journals The Role of MicroRNAs in Regulating Cytokines and Growth Factors in Coronary Artery Disease: The Ins and Outs

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Armita Mahdavi Gorabi ◽  
Nasim Kiaie ◽  
Thozhukat Sathyapalan ◽  
Khalid Al-Rasadi ◽  
Tannaz Jamialahmadi ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Growth Factors ◽  
Coronary Artery ◽  
Coronary Artery Diseases ◽  
Comprehensive Overview ◽  
The World ◽  
Key Players ◽  
Artery Disease ◽  
Underlying Mechanisms

Coronary artery diseases (CAD), as a leading cause of mortality around the world, has attracted the researchers’ attention for years to find out its underlying mechanisms and causes. Among the various key players in the pathogenesis of CAD cytokines, microRNAs (miRNAs) are crucial. In this study, besides providing a comprehensive overview of the involvement of cytokines, growth factors, and miRNAs in CAD, the interplay between miRNA with cytokine or growth factors during the development of CAD is discussed.

Up-regulation of 11β-Hydroxysteroid Dehydrogenase Type 2 Expression by Hedgehog Ligand Contributes to the Conversion of Cortisol Into Cortisone

Endocrinology ◽  
2016 ◽  
Vol 157 (9) ◽  
pp. 3529-3539 ◽  
Author(s):  
Haibin Zhu ◽  
Chaochun Zou ◽  
Xueying Fan ◽  
Wenyi Xiong ◽  
Lanfang Tang ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Fetal Development ◽  
Promoter Region ◽  
Hydroxysteroid Dehydrogenase ◽  
Hh Signaling ◽  
Underlying Mechanisms ◽  
Main Components ◽  
Expression And Activity

The cortisol-inactivating enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) that catalyzes the intracellular inactivation of glucocorticoids plays a pivotal role in human pregnant maintenance and normal fetal development. Given the fact that the main components of Hedgehog (HH) signaling pathway are predominantly expressed in syncytial layer of human placental villi where 11β-HSD2 is robustly expressed, in the present study, we have investigated the potential roles and underlying mechanisms of HH signaling in 11β-HSD2 expression. Activation of HH signaling by a variety of approaches robustly induced 11β-HSD2 expression as well as the 11β-HSD2 activity, whereas suppression of HH signaling significantly attenuated 11β-HSD2 expression as well as the 11β-HSD2 activity in both human primary cytotrophoblasts and trophoblast-like BeWo cells. Moreover, among glioma-associated oncogene (GLI) family transcriptional factors in HH signaling, knockdown of GLI2 but not GLI1 and GLI3 significantly attenuated HH-induced 11β-HSD2 expression and activity, and overexpression of GLI2 activator alone was sufficient to induce 11β-HSD2 expression and activity. Finally, GLI2 not only directly bound to the promoter region of gene hsd11b2 to transactivate hsd11b2 but also formed a heterodimer with RNA polymerase II, an enzyme that catalyzes the transcription of DNA to synthesize mRNAs, resulting in up-regulation of hsd11b2 gene transcription. Taken together, the present study has uncovered a hitherto uncharacterized role of HH/GLI2 signaling in 11β-HSD2 regulation, implicating that HH signaling through GLI2 could be required for the human pregnant maintenance and fetal development.

Response Interference as a Mechanism Underlying Implicit Measures

2008 ◽  
Vol 24 (4) ◽  
pp. 218-225 ◽  
Author(s):  
Bertram Gawronski ◽  
Roland Deutsch ◽  
Etienne P. LeBel ◽  
Kurt R. Peters
Keyword(s):  
Task Performance ◽  
Psychological Research ◽  
Implicit Measures ◽  
Mediation Model ◽  
Response Interference ◽  
Relevant Evidence ◽  
Moderated Mediation Model ◽  
Stimulus Features ◽  
Underlying Mechanisms

Over the last decade, implicit measures of mental associations (e.g., Implicit Association Test, sequential priming) have become increasingly popular in many areas of psychological research. Even though successful applications provide preliminary support for the validity of these measures, their underlying mechanisms are still controversial. The present article addresses the role of a particular mechanism that is hypothesized to mediate the influence of activated associations on task performance in many implicit measures: response interference (RI). Based on a review of relevant evidence, we argue that RI effects in implicit measures depend on participants’ attention to association-relevant stimulus features, which in turn can influence the reliability and the construct validity of these measures. Drawing on a moderated-mediation model (MMM) of task performance in RI paradigms, we provide several suggestions on how to address these problems in research using implicit measures.

The More You Say, the Less They Hear

2015 ◽  
Vol 27 (4) ◽  
pp. 159-169 ◽  
Author(s):  
Elsbeth D. Asbeek Brusse ◽  
Marieke L. Fransen ◽  
Edith G. Smit
Keyword(s):  
Hearing Protection ◽  
Entertainment Education ◽  
Mediating Role ◽  
Attitude Measures ◽  
Underlying Mechanisms

Abstract. This study examined the effects of disclosure messages in entertainment-education (E-E) on attitudes toward hearing protection and attitude toward the source. In addition, the (mediating) role of the underlying mechanisms (i.e., transportation, identification, and counterarguing) was studied. In an experiment (N = 336), three different disclosure messages were compared with a no-disclosure condition. The results show that more explicit disclosure messages negatively affect transportation and identification and stimulate the generation of counterarguments. In addition, the more explicit disclosure messages affect both attitude measures via two of these processes (i.e., transportation and counterarguing). Less explicit disclosure messages do not have this effect. Implications of the findings are discussed.

Autophagy Modulators and Neuroinflammation

2020 ◽  
Vol 27 (6) ◽  
pp. 955-982 ◽  
Author(s):  
Kyoung Sang Cho ◽  
Jang Ho Lee ◽  
Jeiwon Cho ◽  
Guang-Ho Cha ◽  
Gyun Jee Song
Keyword(s):  
Neurodegenerative Disorders ◽  
Neurological Disorders ◽  
Mammalian Cells ◽  
Critical Role ◽  
Therapeutic Agents ◽  
Mechanisms Of Action ◽  
Scientific Interest ◽  
Therapeutic Tools ◽  
Underlying Mechanisms

Background: Neuroinflammation plays a critical role in the development and progression of various neurological disorders. Therefore, various studies have focused on the development of neuroinflammation inhibitors as potential therapeutic tools. Recently, the involvement of autophagy in the regulation of neuroinflammation has drawn substantial scientific interest, and a growing number of studies support the role of impaired autophagy in the pathogenesis of common neurodegenerative disorders. Objective: The purpose of this article is to review recent research on the role of autophagy in controlling neuroinflammation. We focus on studies employing both mammalian cells and animal models to evaluate the ability of different autophagic modulators to regulate neuroinflammation. Methods: We have mostly reviewed recent studies reporting anti-neuroinflammatory properties of autophagy. We also briefly discussed a few studies showing that autophagy modulators activate neuroinflammation in certain conditions. Results: Recent studies report neuroprotective as well as anti-neuroinflammatory effects of autophagic modulators. We discuss the possible underlying mechanisms of action of these drugs and their potential limitations as therapeutic agents against neurological disorders. Conclusion: Autophagy activators are promising compounds for the treatment of neurological disorders involving neuroinflammation.

Inflammatory Biomarkers in Atrial Fibrillation

2019 ◽  
Vol 26 (5) ◽  
pp. 837-854 ◽  
Author(s):  
Effimia Zacharia ◽  
Nikolaos Papageorgiou ◽  
Adam Ioannou ◽  
Gerasimos Siasos ◽  
Spyridon Papaioannou ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Plasma Levels ◽  
Large Scale ◽  
Inflammatory Biomarkers ◽  
Inflammatory Pathways ◽  
Inflammatory State ◽  
Anti Inflammatory ◽  
Underlying Mechanisms

During the last few years, a significant number of studies have attempted to clarify the underlying mechanisms that lead to the presentation of atrial fibrillation (AF). Inflammation is a key component of the pathophysiological processes that lead to the development of AF; the amplification of inflammatory pathways triggers AF, and, in tandem, AF increases the inflammatory state. Indeed, the plasma levels of several inflammatory biomarkers are elevated in patients with AF. In addition, the levels of specific inflammatory biomarkers may provide information regarding to the AF duration. Several small studies have assessed the role of anti-inflammatory treatment in atrial fibrillation but the results have been contradictory. Large-scale studies are needed to evaluate the role of inflammation in AF and whether anti-inflammatory medications should be routinely administered to patients with AF.

Using serum biomarkers for identifying unstable carotid plaque: update of current evidence

2020 ◽  
Vol 26 ◽  
Author(s):  
Areti Sofogianni ◽  
Konstantinos Tziomalos ◽  
Triantafyllia Koletsa ◽  
Apostolos G. Pitoulias ◽  
Lemonia Skoura ◽  
...  
Keyword(s):  
High Risk ◽  
Great Proportion ◽  
Current Literature ◽  
Early Identification ◽  
Carotid Plaque ◽  
Potential Role ◽  
Carotid Atherosclerosis ◽  
Serum Biomarkers ◽  
Current Evidence

: Carotid atherosclerosis is responsible for a great proportion of ischemic strokes. Early identification of unstable or vulnerable carotid plaques and therefore of patients at high risk for stroke is of significant medical and socioeconomical value. We reviewed the current literature and discuss the potential role of the most important serum biomarkers in identifying patients with carotid atherosclerosis who are at high risk for atheroembolic stroke.

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