scholarly journals Multiple Functional Neurosteroid Binding Sites on GABAA Receptors

2018 ◽  
Author(s):  
Zi-Wei Chen ◽  
John R. Bracamontes ◽  
Melissa M. Budelier ◽  
Allison L. Germann ◽  
Daniel J. Shin ◽  
...  
Keyword(s):  
Binding Sites ◽  
Neuronal Excitability ◽  
System Development ◽  
Docking Studies ◽  
Ring Structure ◽  
Nervous System Development ◽  
Computational Docking ◽  
Anesthetic Agents ◽  
Electrophysiological Studies ◽  
Endogenous Modulators

AbstractNeurosteroids are endogenous modulators of neuronal excitability and nervous system development and are being developed as anesthetic agents and treatments for psychiatric diseases. While GABAA receptors are the primary molecular targets of neurosteroid action, the structural details of neurosteroid binding to these proteins remain ill-defined. We synthesized neurosteroid analogue photolabeling reagents in which the photolabeling groups were placed at three positions around the neurosteroid ring structure, enabling identification of binding sites and mapping of neurosteroid orientation within these sites. Using middle-down mass spectrometry, we identified three clusters of photolabeled residues representing three distinct neurosteroid binding sites in the human α1β3GABAA receptor. Novel intrasubunit binding sites were identified within the transmembrane helical bundles of both the α1 and β3 subunits, adjacent to the extracellular domains. An intersubunit site in the interface between the β3(+) and α1(-) subunits of the GABAA receptor pentamer was also identified. Computational docking studies of neurosteroid to the three sites predicted critical residues contributing to neurosteroid interaction with the GABAA receptors. Electrophysiological studies based on these predictions indicate that both the α1 intrasubunit and β3-α1 intersubunit sites are critical for neurosteroid action.

scholarly journals Common binding by redundant group B Sox proteins is evolutionarily conserved in Drosophila

2014 ◽  
Author(s):  
Sarah H Carl ◽  
Steven Russell
Keyword(s):  
Binding Site ◽  
Binding Sites ◽  
Regulatory Networks ◽  
System Development ◽  
Nervous System Development ◽  
Phylogenetic Distance ◽  
Functional Sites ◽  
Sox Proteins ◽  
Alternative Sources ◽  
Group B

Background: Group B Sox proteins are a highly conserved group of transcription factors that act extensively to coordinate nervous system development in higher metazoans while showing both co-expression and functional redundancy across a broad group of taxa. In Drosophila melanogaster, the two group B Sox proteins Dichaete and SoxNeuro show widespread common binding across the genome. While some instances of functional compensation have been observed in Drosophila, the function of common binding and the extent of its evolutionary conservation is not known. Results: We used DamID-seq to examine the genome-wide binding patterns of Dichaete and SoxNeuro in four species of Drosophila. Through a quantitative comparison of Dichaete binding, we evaluated the rate of binding site turnover across the genome as well as at specific functional sites. We also examined the presence of Sox motifs within binding intervals and the correlation between sequence conservation and binding conservation. To determine whether common binding between Dichaete and SoxNeuro is conserved, we performed a detailed analysis of the binding patterns of both factors in two species. Conclusion: We find that, while the regulatory networks driven by Dichaete and SoxNeuro are largely conserved across the drosophilids studied, binding site turnover is widespread and correlated with phylogenetic distance. Nonetheless, binding is preferentially conserved at known cis-regulatory modules and core, independently verified binding sites. We observed the strongest binding conservation at sites that are commonly bound by Dichaete and SoxNeuro, suggesting that these sites are functionally important. Our analysis provides insights into the evolution of group B Sox function, highlighting the specific conservation of shared binding sites and suggesting alternative sources of neofunctionalisation between paralogous family members.

scholarly journals Drebrin regulates cytoskeleton dynamics in migrating neurons through interaction with CXCR4

2021 ◽  
Vol 118 (3) ◽  
pp. e2009493118
Author(s):  
Yufei Shan ◽  
Stephen Matthew Farmer ◽  
Susan Wray
Keyword(s):  
Neuronal Migration ◽  
Binding Sites ◽  
Cortical Neurons ◽  
Actin Polymerization ◽  
Granule Cells ◽  
System Development ◽  
Super Resolution ◽  
Direct Interaction ◽  
Nervous System Development ◽  
Gnrh Neurons

Stromal cell-derived factor-1 (SDF-1) and chemokine receptor type 4 (CXCR4) are regulators of neuronal migration (e.g., GnRH neurons, cortical neurons, and hippocampal granule cells). However, how SDF-1/CXCR4 alters cytoskeletal components remains unclear. Developmentally regulated brain protein (drebrin) stabilizes actin polymerization, interacts with microtubule plus ends, and has been proposed to directly interact with CXCR4 in T cells. The current study examined, in mice, whether CXCR4 under SDF-1 stimulation interacts with drebrin to facilitate neuronal migration. Bioinformatic prediction of protein–protein interaction highlighted binding sites between drebrin and crystallized CXCR4. In migrating GnRH neurons, drebrin, CXCR4, and the microtubule plus-end binding protein EB1 were localized close to the cell membrane. Coimmunoprecipitation (co-IP) confirmed a direct interaction between drebrin and CXCR4 using wild-type E14.5 whole head and a GnRH cell line. Analysis of drebrin knockout (DBN1 KO) mice showed delayed migration of GnRH cells into the brain. A decrease in hippocampal granule cells was also detected, and co-IP confirmed a direct interaction between drebrin and CXCR4 in PN4 hippocampi. Migration assays on primary neurons established that inhibiting drebrin (either pharmacologically or using cells from DBN1 KO mice) prevented the effects of SDF-1 on neuronal movement. Bioinformatic prediction then identified binding sites between drebrin and the microtubule plus end protein, EB1, and super-resolution microscopy revealed decreased EB1 and drebrin coexpression after drebrin inhibition. Together, these data show a mechanism by which a chemokine, via a membrane receptor, communicates with the intracellular cytoskeleton in migrating neurons during central nervous system development.

Neuronal Excitability in Epileptogenic Zones Regulated by the Wnt/ Β-Catenin Pathway

2020 ◽  
Vol 19 (1) ◽  
pp. 2-11 ◽  
Author(s):  
Carmen Rubio ◽  
Elisa Taddei ◽  
Jorge Acosta ◽  
Verónica Custodio ◽  
Carlos Paz
Keyword(s):  
Neuronal Excitability ◽  
System Development ◽  
Wnt Signaling Pathway ◽  
Epileptic Seizures ◽  
Epileptic Activity ◽  
Nervous System Development ◽  
Hippocampal Neurogenesis ◽  
Mitochondrial Regulation ◽  
The Central Nervous System ◽  
And Function

: Epilepsy is a neurological disorder that involves abnormal and recurrent neuronal discharges, producing epileptic seizures. Recently, it has been proposed that the Wnt signaling pathway is essential for the central nervous system development and function because it modulates important processes such as hippocampal neurogenesis, synaptic clefting, and mitochondrial regulation. Wnt/β- catenin signaling regulates changes induced by epileptic seizures, including neuronal death. Several genetic studies associate Wnt/β-catenin signaling with neuronal excitability and epileptic activity. Mutations and chromosomal defects underlying syndromic or inherited epileptic seizures have been identified. However, genetic factors underlying the susceptibility of an individual to develop epileptic seizures have not been fully studied yet. In this review, we describe the genes involved in neuronal excitability in epileptogenic zones dependent on the Wnt/β-catenin pathway.

Genes required for axon pathfinding and extension in the C. elegans nerve ring

Development ◽  
1999 ◽  
Vol 126 (16) ◽  
pp. 3679-3692 ◽  
Author(s):  
J.A. Zallen ◽  
S.A. Kirch ◽  
C.I. Bargmann
Keyword(s):  
Axon Guidance ◽  
Fluorescent Protein ◽  
System Development ◽  
Axon Growth ◽  
Ring Structure ◽  
Nervous System Development ◽  
Nerve Ring ◽  
Eph Receptor ◽  
Axon Extension ◽  
Growth Guidance

Over half of the neurons in Caenorhabditis elegans send axons to the nerve ring, a large neuropil in the head of the animal. Genetic screens in animals that express the green fluorescent protein in a subset of sensory neurons identified eight new sax genes that affect the morphology of nerve ring axons. sax-3/robo mutations disrupt axon guidance in the nerve ring, while sax-5, sax-9 and unc-44 disrupt both axon guidance and axon extension. Axon extension and guidance proceed normally in sax-1, sax-2, sax-6, sax-7 and sax-8 mutants, but these animals exhibit later defects in the maintenance of nerve ring structure. The functions of existing guidance genes in nerve ring development were also examined, revealing that SAX-3/Robo acts in parallel to the VAB-1/Eph receptor and the UNC-6/netrin, UNC-40/DCC guidance systems for ventral guidance of axons in the amphid commissure, a major route of axon entry into the nerve ring. In addition, SAX-3/Robo and the VAB-1/Eph receptor both function to prevent aberrant axon crossing at the ventral midline. Together, these genes define pathways required for axon growth, guidance and maintenance during nervous system development.

Transcriptional profiling of iPSC-derived neurons with reciprocal monogenic CNV in 3p26.3 region

2020 ◽  
pp. 10-11
Author(s):  
М.Е. Лопаткина ◽  
В.С. Фишман ◽  
М.М. Гридина ◽  
Н.А. Скрябин ◽  
Т.В. Никитина ◽  
...  
Keyword(s):  
Gene Expression ◽  
Copy Number ◽  
System Development ◽  
Transcriptional Profiling ◽  
Global Gene Expression ◽  
Nervous System Development ◽  
Number Variation ◽  
The Central Nervous System ◽  
Cntn6 Gene ◽  
Copy Number Changes

Проведен анализ генной экспрессии в нейронах, дифференцированных из индуцированных плюрипотентных стволовых клеток пациентов с идиопатическими интеллектуальными нарушениями и реципрокными хромосомными мутациями в регионе 3p26.3, затрагивающими единственный ген CNTN6. Для нейронов с различным типом хромосомных аберраций была показана глобальная дисрегуляция генной экспрессии. В нейронах с вариациями числа копий гена CNTN6 была снижена экспрессия генов, продукты которых вовлечены в процессы развития центральной нервной системы. The gene expression analysis of iPSC-derived neurons, obtained from patients with idiopathic intellectual disability and reciprocal microdeletion and microduplication in 3p26.3 region affecting the single CNTN6 gene was performed. The global gene expression dysregulation was demonstrated for cells with CNTN6 copy number variation. Gene expression in neurons with CNTN6 copy number changes was downregulated for genes, whose products are involved in the central nervous system development.

Covalent-Fragment Screening of Brd4 Identifies a Ligandable Site Orthogonal to the Acetyl-Lysine Binding Sites

2019 ◽  
Author(s):  
Michael Olp ◽  
Daniel Sprague ◽  
Stefan Kathman ◽  
Ziyang Xu ◽  
Alexandar Statsyuk ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Binding Site ◽  
Binding Sites ◽  
Computational Prediction ◽  
Chemical Probes ◽  
Computational Docking ◽  
Fragment Screening ◽  
Covalent Inhibitors ◽  
Bet Protein ◽  
Proof Of Principle

<p>Brd4, a member of the bromodomain and extraterminal domain (BET) family, has emerged as a promising epigenetic target in cancer and inflammatory disorders. All reported BET family ligands bind within the bromodomain acetyl-lysine binding sites and competitively inhibit BET protein interaction with acetylated chromatin. Alternative chemical probes that act orthogonally to the highly-conserved acetyl-lysine binding sites may exhibit selectivity within the BET family and avoid recently reported toxicity in clinical trials of BET bromodomain inhibitors. Here, we report the first identification of a ligandable site on a bromodomain outside the acetyl-lysine binding site. Inspired by our computational prediction of hotspots adjacent to non-homologous cysteine residues within the <i>C</i>-terminal Brd4 bromodomain (Brd4-BD2), we performed a mid-throughput mass spectrometry screen to identify cysteine-reactive fragments that covalently and selectively modify Brd4. Subsequent mass spectrometry, NMR and computational docking analyses of electrophilic fragment hits revealed a novel ligandable site near Cys356 that is unique to Brd4 among all human bromodomains. This site is orthogonal to the Brd4-BD2 acetyl-lysine binding site as Cys356 modification did not impact binding of the pan-BET bromodomain inhibitor JQ1 in fluorescence polarization assays. Finally, we tethered covalent fragments to JQ1 and performed NanoBRET assays to provide proof of principle that this orthogonal site can be covalently targeted in intact human cells. Overall, we demonstrate the potential of targeting sites orthogonal to bromodomain acetyl-lysine binding sites to develop bivalent and covalent inhibitors that displace Brd4 from chromatin.</p>

Exogenous Neonatal Erythropoietin Mitigates Brain Damage After a Combination of Prenatal Hypoxic-Ischemia and Lipopolysaccharide Inflammation in Rats

2008 ◽  
Vol 1 (4) ◽  
pp. A353
Author(s):  
Shenandoah Robinson ◽  
Qing Li
Keyword(s):  
Brain Damage ◽  
Intracellular Signaling ◽  
System Development ◽  
Intrauterine Infection ◽  
Artery Occlusion ◽  
Nervous System Development ◽  
Human Infants ◽  
Hypoxic Ischemia ◽  
Show Evidence ◽  
The Impact

Introduction Many infants born very preterm who suffer brain damage most likely experienced a combined insult from intrauterine infection and placental insufficiency. Damage is thought to be synergistic rather than additive but the mechanisms of combined injury remain elusive. A combination of lipopolysaccharide-induced inflammation and hypoxia-ischemia has been used in rats to model the dual insult that occurs in human infants prenatally. Erythropoietin, a pleiotrophic cytokine that is essential for central nervous system development, ameliorates brain injury after isolated hypoxic-ischemic or inflammatory insults through different intracellular signaling pathways. We hypothesized that exogenous neonatal EPO administration would lessen the damage of a combined prenatal insult in rats. Methods On embryonic Day 18 fetal rats experienced 60 minutes of transient uterine artery occlusion with or without intracervical LPS administration with sham controls receiving surgery but no occlusion and saline for LPS. Survival was recorded and histological biochemical and functional assays were performed. Means were compared with ANOVA with Tukey HSD post hoc analysis. Results After a combined insult of HI and 0.15-mg/kg LPS on E18 the survival of pups by postnatal Day 1 (P1) decreased from 77% with HI alone to 22% for LPS plus HI. When exogenous systemic EPO was administered P1–P3 survival to P9 improved markedly from 40% (2 of 5) for saline-treated insult pups to 100% (6 of 6) for EPO-treated. Initial histological analyses show EPO decreases the number of brain activated caspase 3 and activated microglia by P9. Additional analyses will be presented. Conclusion As at least 60% of placentas from infants born pre-term show evidence of chorioamnionitis, assessment of the impact of exogenous EPO on a model of a combination injury is essential prior to proceeding with a clinical trial. Initial results indicate neonatal exogenous EPO mitigates damage from the combined insult.

Antenatal Glucocorticoids Supplementation and Central Nervous System Development

2013 ◽  
Vol 14 (2) ◽  
pp. 160-166
Author(s):  
Diego Gazzolo ◽  
Laura D. Serpero ◽  
Alessandro Frigiola ◽  
Raul Abella ◽  
Alessandro Giamberti ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
System Development ◽  
Nervous System Development ◽  
Central Nervous System Development

Association of Micro RNA and Postoperative Cognitive Dysfunction: A Review

2020 ◽  
Vol 20 (17) ◽  
pp. 1781-1790
Author(s):  
Noor Anisah Abu Yazit ◽  
Norsham Juliana ◽  
Srijit Das ◽  
Nur Islami Mohd Fahmi Teng ◽  
Nadia Mohd Fahmy ◽  
...  
Keyword(s):  
Cognitive Dysfunction ◽  
Chromosomal Abnormalities ◽  
Current Knowledge ◽  
System Development ◽  
Genetic Disorder ◽  
Postoperative Cognitive Dysfunction ◽  
Clinical Importance ◽  
Nervous System Development ◽  
Micro Rna ◽  
A Genome

Postoperative Cognitive Dysfunction (POCD) refers to the condition of neurocognitive decline following surgery in a cognitive and sensory manner. There are several risk factors, which may be life-threatening for this condition. Neuropsychological assessment of this condition is very important. In the present review, we discuss the association of apolipoprotein epsilon 4 (APOE ε4) and few miRNAs with POCD, and highlight the clinical importance for prognosis, diagnosis and treatment of POCD. Microarray is a genome analysis that can be used to determine DNA abnormalities. This current technique is rapid, efficient and high-throughout. Microarray techniques are widely used to diagnose diseases, particularly in genetic disorder, chromosomal abnormalities, mutations, infectious diseases and disease-relevant biomarkers. MicroRNAs (miRNAs) are a class of non-coding RNAs that are widely found distributed in eukaryotes. Few miRNAs influence the nervous system development, and nerve damage repair. Microarray approach can be utilized to understand the miRNAs involved and their pathways in POCD development, unleashing their potential to be considered as a diagnostic marker for POCD. This paper summarizes and identifies the studies that use microarray based approaches for POCD analysis. Since the application of microarray in POCD is expanding, there is a need to review the current knowledge of this approach.

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