scholarly journals Near-atomic model of microtubule-tau interactions

Science ◽  
2018 ◽  
Vol 360 (6394) ◽  
pp. 1242-1246 ◽  
Author(s):  
Elizabeth H. Kellogg ◽  
Nisreen M. A. Hejab ◽  
Simon Poepsel ◽  
Kenneth H. Downing ◽  
Frank DiMaio ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Atomic Model ◽  
Developmentally Regulated ◽  
Computational Approaches ◽  
Atomic Models ◽  
Cryo Electron Microscopy ◽  
Tubulin Binding ◽  
Axonal Protein

Tau is a developmentally regulated axonal protein that stabilizes and bundles microtubules (MTs). Its hyperphosphorylation is thought to cause detachment from MTs and subsequent aggregation into fibrils implicated in Alzheimer’s disease. It is unclear which tau residues are crucial for tau-MT interactions, where tau binds on MTs, and how it stabilizes them. We used cryo–electron microscopy to visualize different tau constructs on MTs and computational approaches to generate atomic models of tau-tubulin interactions. The conserved tubulin-binding repeats within tau adopt similar extended structures along the crest of the protofilament, stabilizing the interface between tubulin dimers. Our structures explain the effect of phosphorylation on MT affinity and lead to a model of tau repeats binding in tandem along protofilaments, tethering together tubulin dimers and stabilizing polymerization interfaces.

scholarly journals High-throughput screening of natural compounds and inhibition of a major therapeutic target HsGSK-3β for Alzheimer’s disease using computational approaches

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Rohit Shukla ◽  
Tiratha Raj Singh
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
High Throughput Screening ◽  
Complex Disease ◽  
Glycogen Synthase ◽  
Binding Free Energy ◽  
Drug Candidate ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Computational Approaches

Abstract Background Alzheimer’s disease is a leading neurodegenerative disease worldwide and is the 6th leading cause of death in the USA. AD is a very complex disease and the drugs available in the market cannot fully cure it. The glycogen synthase kinase 3 beta plays a major role in the hyperphosphorylation of tau protein which forms the neurofibrillary tangles which is a major hallmark of AD. In this study, we have used a series of computational approaches to find novel inhibitors against GSK-3β to reduce the TAU hyperphosphorylation. Results We have retrieved a set of compounds (n=167,741) and screened against GSK-3β in four sequential steps. The resulting analysis of virtual screening suggested that 404 compounds show good binding affinity and can be employed for pharmacokinetic analysis. From here, we have selected 20 compounds those were good in terms of pharmacokinetic parameters. All these compounds were re-docked by using Autodock Vina followed by Autodock. Four best compounds were employed for MDS and here predicted RMSD, RMSF, Rg, hydrogen bonds, SASA, PCA, and binding-free energy. From all these analyses, we have concluded that out of 167,741 compounds, the ZINC15968620, ZINC15968622, and ZINC70707119 can act as lead compounds against HsGSK-3β to reduce the hyperphosphorylation. Conclusion The study suggested three compounds (ZINC15968620, ZINC15968622, and ZINC70707119) have great potential to be a drug candidate and can be tested using in vitro and in vivo experiments for further characterization and applications.

scholarly journals The structure of the yeast Ctf3 complex

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Stephen M Hinshaw ◽  
Andrew N Dates ◽  
Stephen C Harrison
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
High Resolution ◽  
Atomic Model ◽  
Kinetochore Assembly ◽  
Cryo Electron Microscopy ◽  
Molecular Interpretation ◽  
Spindle Microtubules ◽  
And Function ◽  
Assembly Site

Kinetochores are the chromosomal attachment points for spindle microtubules. They are also signaling hubs that control major cell cycle transitions and coordinate chromosome folding. Most well-studied eukaryotes rely on a conserved set of factors, which are divided among two loosely-defined groups, for these functions. Outer kinetochore proteins contact microtubules or regulate this contact directly. Inner kinetochore proteins designate the kinetochore assembly site by recognizing a specialized nucleosome containing the H3 variant Cse4/CENP-A. We previously determined the structure, resolved by cryo-electron microscopy (cryo-EM), of the yeast Ctf19 complex (Ctf19c, homologous to the vertebrate CCAN), providing a high-resolution view of inner kinetochore architecture (Hinshaw and Harrison, 2019). We now extend these observations by reporting a near-atomic model of the Ctf3 complex, the outermost Ctf19c sub-assembly seen in our original cryo-EM density. The model is sufficiently well-determined by the new data to enable molecular interpretation of Ctf3 recruitment and function.

scholarly journals Atomic model of microtubule-bound tau

2018 ◽  
Author(s):  
Elizabeth H. Kellogg ◽  
Nisreen M.A. Hejab ◽  
Simon Poepsel ◽  
Kenneth H. Downing ◽  
Frank DiMaio ◽  
...  
Keyword(s):  
High Resolution ◽  
Physiological Role ◽  
Biochemical Data ◽  
Disease Pathogenesis ◽  
Developmentally Regulated ◽  
Computational Approaches ◽  
Selective Stabilization ◽  
Tubulin Binding ◽  
Future Treatments ◽  
Β Tubulin

AbstractTau is a developmentally regulated protein found in axons, whose physiological role is to stabilize and bundle microtubules (MTs). Hyper-phosphorylation of tau is thought to cause its detachment from MTs and subsequent aggregation into pathological fibrils that have been implicated in Alzheimer’s disease pathogenesis. Despite its known MT binding role, there is no consensus regarding which tau residues are crucial for tau-MT interactions, where on the MT tau binds, and how binding results in MT stabilization. We have used cryo-EM to visualize the interaction of different tau constructs with MTs at high resolution (3.2-4.8 Å) and used computational approaches to generate atomic models of tau-tubulin interactions. Our work shows that the highly conserved tubulin-binding repeats within tau adopt very similar structures in their interactions with the MT. Each tau repeat binds the MT exterior and adopts an extended structure along the crest of the protofilament (PF), interacting with both α- and β-tubulin, thus stabilizing the interface between tubulin dimers. Our structures agree with and explain previous biochemical data concerning the effect of phosphorylation on MT affinity and lead to a model in which tau repeats bind in tandem along a PF, tethering together tubulin dimers and stabilizing longitudinal polymerization interfaces. These structural findings could establish a basis of future treatments aiming at the selective stabilization of tau-MT interactions.

scholarly journals Three-dimensional analysis of synaptic organization in the hippocampal CA1 field in Alzheimer’s disease

Brain ◽  
2020 ◽  
Author(s):  
Marta Montero-Crespo ◽  
Marta Domínguez-Álvaro ◽  
Lidia Alonso-Nanclares ◽  
Javier DeFelipe ◽  
Lidia Blazquez-Llorca
Keyword(s):  
Electron Microscopy ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Β ◽  
Cortical Atrophy ◽  
Structural Basis ◽  
Synaptic Organization ◽  
Synaptic Density ◽  
Early Stages ◽  
Late Stages

Abstract Alzheimer’s disease is the most common form of dementia, characterized by a persistent and progressive impairment of cognitive functions. Alzheimer’s disease is typically associated with extracellular deposits of amyloid-β peptide and accumulation of abnormally phosphorylated tau protein inside neurons (amyloid-β and neurofibrillary pathologies). It has been proposed that these pathologies cause neuronal degeneration and synaptic alterations, which are thought to constitute the major neurobiological basis of cognitive dysfunction in Alzheimer’s disease. The hippocampal formation is especially vulnerable in the early stages of Alzheimer’s disease. However, the vast majority of electron microscopy studies have been performed in animal models. In the present study, we performed an extensive 3D study of the neuropil to investigate the synaptic organization in the stratum pyramidale and radiatum in the CA1 field of Alzheimer’s disease cases with different stages of the disease, using focused ion beam/scanning electron microscopy (FIB/SEM). In cases with early stages of Alzheimer’s disease, the synapse morphology looks normal and we observed no significant differences between control and Alzheimer’s disease cases regarding the synaptic density, the ratio of excitatory and inhibitory synapses, or the spatial distribution of synapses. However, differences in the distribution of postsynaptic targets and synaptic shapes were found. Furthermore, a lower proportion of larger excitatory synapses in both strata were found in Alzheimer’s disease cases. Individuals in late stages of the disease suffered the most severe synaptic alterations, including a decrease in synaptic density and morphological alterations of the remaining synapses. Since Alzheimer’s disease cases show cortical atrophy, our data indicate a reduction in the total number (but not the density) of synapses at early stages of the disease, with this reduction being much more accentuated in subjects with late stages of Alzheimer’s disease. The observed synaptic alterations may represent a structural basis for the progressive learning and memory dysfunctions seen in Alzheimer’s disease cases.

Dendritic and spinal pathology in the acoustic cortex in Alzheimer's disease: morphological and morphometric estimation by Golgi technique and electron microscopy

2007 ◽  
Vol 127 (4) ◽  
pp. 351-354 ◽  
Author(s):  
Stavros J. Baloyannis ◽  
Vassiliki Costa ◽  
Ioannis Mauroudis ◽  
Demetrios Psaroulis ◽  
Spyros L. Manolides ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Golgi Technique
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