scholarly journals Loss of Ftsj1 perturbs codon-specific translation efficiency in the brain and is associated with X-linked intellectual disability

2021 ◽  
Vol 7 (13) ◽  
pp. eabf3072
Author(s):  
Y. Nagayoshi ◽  
T. Chujo ◽  
S. Hirata ◽  
H. Nakatsuka ◽  
C.-W. Chen ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
State Level ◽  
Memory Deficits ◽  
Ribosome Profiling ◽  
Translation Efficiency ◽  
Trna Modification ◽  
Synaptic Organization ◽  
Transfer Rnas ◽  
The Brain

FtsJ RNA 2′-O-methyltransferase 1 (FTSJ1) gene has been implicated in X-linked intellectual disability (XLID), but the molecular pathogenesis is unknown. We show that Ftsj1 is responsible for 2′-O-methylation of 11 species of cytosolic transfer RNAs (tRNAs) at the anticodon region, and these modifications are abolished in Ftsj1 knockout (KO) mice and XLID patient–derived cells. Loss of 2′-O-methylation in Ftsj1 KO mouse selectively reduced the steady-state level of tRNAPhe in the brain, resulting in a slow decoding at Phe codons. Ribosome profiling showed that translation efficiency is significantly reduced in a subset of genes that need to be efficiently translated to support synaptic organization and functions. Ftsj1 KO mice display immature synaptic morphology and aberrant synaptic plasticity, which are associated with anxiety-like and memory deficits. The data illuminate a fundamental role of tRNA modification in the brain through regulation of translation efficiency and provide mechanistic insights into FTSJ1-related XLID.

scholarly journals Seeking a Role for Translational Control by Alternative Polyadenylation in Saccharomyces cerevisiae

2021 ◽  
Vol 9 (9) ◽  
pp. 1885
Author(s):  
Rachael E. Turner ◽  
Traude H. Beilharz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Translational Control ◽  
Model Organism ◽  
Alternative Polyadenylation ◽  
Ribosome Profiling ◽  
Translation Efficiency ◽  
Mrna Isoforms ◽  
Cleavage And Polyadenylation ◽  
Made In

Alternative polyadenylation (APA) represents an important mechanism for regulating isoform-specific translation efficiency, stability, and localisation. Though some progress has been made in understanding its consequences in metazoans, the role of APA in the model organism Saccharomyces cerevisiae remains a relative mystery because, despite abundant studies on the translational state of mRNA, none differentiate mRNA isoforms’ alternative 3′-end. This review discusses the implications of alternative polyadenylation in S. cerevisiae using other organisms to draw inferences. Given the foundational role that research in this yeast has played in the discovery of the mechanisms of cleavage and polyadenylation and in the drivers of APA, it is surprising that such an inference is required. However, because advances in ribosome profiling are insensitive to APA, how it impacts translation is still unclear. To bridge the gap between widespread observed APA and the discovery of any functional consequence, we also provide a review of the experimental techniques used to uncover the functional importance of 3′ UTR isoforms on translation.

scholarly journals TrmB, a tRNA m7G46 methyltransferase, plays a role in hydrogen peroxide resistance and positively modulates the translation of katA and katB mRNAs in Pseudomonas aeruginosa

2019 ◽  
Vol 47 (17) ◽  
pp. 9271-9281 ◽  
Author(s):  
Narumon Thongdee ◽  
Juthamas Jaroensuk ◽  
Sopapan Atichartpongkul ◽  
Jurairat Chittrakanwong ◽  
Kamonchanok Chooyoung ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pseudomonas Aeruginosa ◽  
Stress Response ◽  
Translational Regulation ◽  
Cellular Response ◽  
Oxidative Stress Response ◽  
Translation Efficiency ◽  
Trna Modification ◽  
Negative Effect

Abstract Cellular response to oxidative stress is a crucial mechanism that promotes the survival of Pseudomonas aeruginosa during infection. However, the translational regulation of oxidative stress response remains largely unknown. Here, we reveal a tRNA modification-mediated translational response to H2O2 in P. aeruginosa. We demonstrated that the P. aeruginosa trmB gene encodes a tRNA guanine (46)-N7-methyltransferase that catalyzes the formation of m7G46 in the tRNA variable loop. Twenty-three tRNA substrates of TrmB with a guanosine residue at position 46 were identified, including 11 novel tRNA substrates. We showed that loss of trmB had a strong negative effect on the translation of Phe- and Asp-enriched mRNAs. The trmB-mediated m7G modification modulated the expression of the catalase genes katA and katB, which are enriched with Phe/Asp codons at the translational level. In response to H2O2 exposure, the level of m7G modification increased, consistent with the increased translation efficiency of Phe- and Asp-enriched mRNAs. Inactivation of trmB led to decreased KatA and KatB protein abundance and decreased catalase activity, resulting in H2O2-sensitive phenotype. Taken together, our observations reveal a novel role of m7G46 tRNA modification in oxidative stress response through translational regulation of Phe- and Asp-enriched genes, such as katA and katB.

scholarly journals Electro-acupuncture Alleviates METH Withdrawal-induced Spatial Memory Deficits by Restoring Astrocyte-drived Glutamate Uptake in dCA1

2020 ◽  
Author(s):  
Pengbo Shi ◽  
Zhaosu Li ◽  
Xing Xu ◽  
Jiaxun Nie ◽  
Dekang Liu ◽  
...  
Keyword(s):  
Spatial Memory ◽  
Cognitive Deficits ◽  
Glutamate Uptake ◽  
Cognitive Disorders ◽  
Memory Deficits ◽  
Therapeutic Interventions ◽  
Therapeutic Effects ◽  
Non Invasive ◽  
The Brain

ABSTRACTMethamphetamine (METH) is frequently abused drug and produces cognitive deficits. METH could induce hyper-glutamatergic state in the brain, which could partially explain METH-related cognitive deficits, but the synaptic etiology remains incompletely understood. To address this issue, we explored the role of dCA1 tripartite synapses and the potential therapeutic effects of electro-acupuncture (EA) in the development of METH withdrawal-induced spatial memory deficits in mice. We found that METH withdrawal weakened astrocytic capacity of glutamate (Glu) uptake, but failed to change Glu release from dCA3, which lead to hyper-glutamatergic excitotoxicity at dCA1 tripartite synapses. By restoring the astrocytic capacity of Glu uptake, EA treatments suppressed the hyper-glutamatergic state and normalized the excitability of postsynaptic neuron in dCA1, finally alleviated spatial memory deficits in METH withdrawal mice. These findings indicate that astrocyte at tripartite synapses might be a key target for developing therapeutic interventions against METH-associated cognitive disorders, and EA represent a promising non-invasive therapeutic strategy for the management of drugs-caused neurotoxicity.

scholarly journals Rewiring of the Serotonin System in Major Depression

2021 ◽  
Vol 12 ◽  
Author(s):  
Faranak Vahid-Ansari ◽  
Paul R. Albert
Keyword(s):  
Mental Illness ◽  
Cognitive Impairment ◽  
Major Depression ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Chronic Treatment ◽  
Brain Regions ◽  
Synaptic Organization ◽  
Serotonin System ◽  
The Brain

Serotonin is a key neurotransmitter that is implicated in a wide variety of behavioral and cognitive phenotypes. Originating in the raphe nuclei, 5-HT neurons project widely to innervate many brain regions implicated in the functions. During the development of the brain, as serotonin axons project and innervate brain regions, there is evidence that 5-HT plays key roles in wiring the developing brain, both by modulating 5-HT innervation and by influencing synaptic organization within corticolimbic structures. These actions are mediated by 14 different 5-HT receptors, with region- and cell-specific patterns of expression. More recently, the role of the 5-HT system in synaptic re-organization during adulthood has been suggested. The 5-HT neurons have the unusual capacity to regrow and reinnervate brain regions following insults such as brain injury, chronic stress, or altered development that result in disconnection of the 5-HT system and often cause depression, anxiety, and cognitive impairment. Chronic treatment with antidepressants that amplify 5-HT action, such as selective serotonin reuptake inhibitors (SSRIs), appears to accelerate the rewiring of the 5-HT system by mechanisms that may be critical to the behavioral and cognitive improvements induced in these models. In this review, we survey the possible 5-HT receptor mechanisms that could mediate 5-HT rewiring and assess the evidence that 5-HT-mediated brain rewiring is impacting recovery from mental illness. By amplifying 5-HT-induced rewiring processes using SSRIs and selective 5-HT agonists, more rapid and effective treatments for injury-induced mental illness or cognitive impairment may be achieved.

Cutting out the middleman: Separating attributional biases from memory deficits

2019 ◽  
Vol 42 ◽  
Author(s):  
Wei-Chun Wang
Keyword(s):  
Implicit Memory ◽  
Memory Retrieval ◽  
Memory Deficits ◽  
Integrative Model ◽  
Prior Work ◽  
Memory Traces ◽  
Attributional Biases ◽  
Cutting Out ◽  
The Brain

Abstract Bastin and colleagues present an integrative model of how recollection- and familiarity-based memories are represented in the brain. While they emphasize the role of attribution mechanisms in shaping memory retrieval, prior work examining implicit memory suggests that memory deficits may be better understood by separating attributional biases from the underlying memory traces.

scholarly journals How Elongator Acetylates tRNA Bases

2020 ◽  
Vol 21 (21) ◽  
pp. 8209
Author(s):  
Nour-el-Hana Abbassi ◽  
Anna Biela ◽  
Sebastian Glatt ◽  
Ting-Yu Lin
Keyword(s):  
Protein Synthesis ◽  
Neurodegenerative Disorders ◽  
Trna Modification ◽  
Acetyl Coa ◽  
Translation Elongation ◽  
Transfer Rnas ◽  
Elongator Complex ◽  
Lysine Acetyltransferase ◽  
Ribosomal Translation

Elp3, the catalytic subunit of the eukaryotic Elongator complex, is a lysine acetyltransferase that acetylates the C5 position of wobble-base uridines (U34) in transfer RNAs (tRNAs). This Elongator-dependent RNA acetylation of anticodon bases affects the ribosomal translation elongation rates and directly links acetyl-CoA metabolism to both protein synthesis rates and the proteome integrity. Of note, several human diseases, including various cancers and neurodegenerative disorders, correlate with the dysregulation of Elongator’s tRNA modification activity. In this review, we focus on recent findings regarding the structure of Elp3 and the role of acetyl-CoA during its unique modification reaction.

scholarly journals The Role of Zinc in Alzheimer's Disease

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Nicole T. Watt ◽  
Isobel J. Whitehouse ◽  
Nigel M. Hooper
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Ampa Receptors ◽  
Critical Role ◽  
Synaptic Cleft ◽  
Memory Deficits ◽  
Zinc Homeostasis ◽  
Glutamatergic Neurons ◽  
The Brain

Zinc, the most abundant trace metal in the brain, has numerous functions, both in health and in disease. Zinc is released into the synaptic cleft of glutamatergic neurons alongside glutamate from where it interacts and modulates NMDA and AMPA receptors. In addition, zinc has multifactorial functions in Alzheimer's disease (AD). Zinc is critical in the enzymatic nonamyloidogenic processing of the amyloid precursor protein (APP) and in the enzymatic degradation of the amyloid-β(Aβ) peptide. Zinc binds to Aβpromoting its aggregation into neurotoxic species, and disruption of zinc homeostasis in the brain results in synaptic and memory deficits. Thus, zinc dyshomeostasis may have a critical role to play in the pathogenesis of AD, and the chelation of zinc is a potential therapeutic approach.

The Role of Mitochondria in the Genesis of Neuroaxonal Dystrophy in the Brains of Aging Mice

1975 ◽  
Vol 33 ◽  
pp. 372-373
Author(s):  
J.E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Present Report ◽  
Light And Electron Microscopy ◽  
Dorsal Column ◽  
Neuroaxonal Dystrophy ◽  
Nucleus Gracilis ◽  
Dystrophic Axons ◽  
The Brain ◽  
Nucleus Cuneatus

Although neuroaxonal dystrophy (NAD) has been examined by light and electron microscopy for years, the nature of the components in the dystrophic axons is not well understood. The present report examines nucleus gracilis and cuneatus (the dorsal column nuclei) in the brain stem of aging mice.Mice (C57BL/6J) were sacrificed by aldehyde perfusion at ages ranging from 3 months to 23 months. Several brain areas and parts of other organs were processed for electron microscopy.At 3 months of age, very little evidence of NAD can be discerned by light microscopy. At the EM level, a few axons are found to contain dystrophic material. By 23 months of age, the entire nucleus gracilis is filled with dystrophic axons. Much less NAD is seen in nucleus cuneatus by comparison. The most recurrent pattern of NAD is an enlarged profile, in the center of which is a mass of reticulated material (reticulated portion; or RP).

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