scholarly journals Ubiquitin stimulated reversal of topoisomerase 2 DNA-protein crosslinks by TDP2

2020 ◽  
Vol 48 (11) ◽  
pp. 6310-6325 ◽  
Author(s):  
Matthew J Schellenberg ◽  
C Denise Appel ◽  
Amanda A Riccio ◽  
Logan R Butler ◽  
Juno M Krahn ◽  
...  
Keyword(s):  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
X Ray ◽  
X Ray Scattering ◽  
Nuclear Extracts ◽  
Topoisomerase 2 ◽  
Uba Domain ◽  
Protein Crosslinks ◽  
Stoichiometric Complex

Abstract Tyrosyl-DNA phosphodiesterase 2 (TDP2) reverses Topoisomerase 2 DNA–protein crosslinks (TOP2-DPCs) in a direct-reversal pathway licensed by ZATTZNF451 SUMO2 E3 ligase and SUMOylation of TOP2. TDP2 also binds ubiquitin (Ub), but how Ub regulates TDP2 functions is unknown. Here, we show that TDP2 co-purifies with K63 and K27 poly-Ubiquitinated cellular proteins independently of, and separately from SUMOylated TOP2 complexes. Poly-ubiquitin chains of ≥ Ub3 stimulate TDP2 catalytic activity in nuclear extracts and enhance TDP2 binding of DNA–protein crosslinks in vitro. X-ray crystal structures and small-angle X-ray scattering analysis of TDP2-Ub complexes reveal that the TDP2 UBA domain binds K63-Ub3 in a 1:1 stoichiometric complex that relieves a UBA-regulated autoinhibitory state of TDP2. Our data indicates that that poly-Ub regulates TDP2-catalyzed TOP2-DPC removal, and TDP2 single nucleotide polymorphisms can disrupt the TDP2-Ubiquitin interface.

Time-Resolved Cryo-Electron Microscopy of Oscillating Microtubules

1990 ◽  
Vol 48 (1) ◽  
pp. 502-503
Author(s):  
Eva-Maria Mandelkow ◽  
Ron Milligan
Keyword(s):  
Electron Microscopy ◽  
Dynamic Instability ◽  
Entire Solution ◽  
Reaction Scheme ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
A Chain ◽  
Ray Scattering

Microtubules form part of the cytoskeleton of eukaryotic cells. They are hollow libers of about 25 nm diameter made up of 13 protofilaments, each of which consists of a chain of heterodimers of α-and β-tubulin. Microtubules can be assembled in vitro at 37°C in the presence of GTP which is hydrolyzed during the reaction, and they are disassembled at 4°C. In contrast to most other polymers microtubules show the behavior of “dynamic instability”, i.e. they can switch between phases of growth and phases of shrinkage, even at an overall steady state [1]. In certain conditions an entire solution can be synchronized, leading to autonomous oscillations in the degree of assembly which can be observed by X-ray scattering (Fig. 1), light scattering, or electron microscopy [2-5]. In addition such solutions are capable of generating spontaneous spatial patterns [6].In an earlier study we have analyzed the structure of microtubules and their cold-induced disassembly by cryo-EM [7]. One result was that disassembly takes place by loss of protofilament fragments (tubulin oligomers) which fray apart at the microtubule ends. We also looked at microtubule oscillations by time-resolved X-ray scattering and proposed a reaction scheme [4] which involves a cyclic interconversion of tubulin, microtubules, and oligomers (Fig. 2). The present study was undertaken to answer two questions: (a) What is the nature of the oscillations as seen by time-resolved cryo-EM? (b) Do microtubules disassemble by fraying protofilament fragments during oscillations at 37°C?

scholarly journals Somatic variants for seed and fruit set in grapevine

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Laura Costantini ◽  
Paula Moreno-Sanz ◽  
Chinedu Charles Nwafor ◽  
Silvia Lorenzi ◽  
Annarita Marrano ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Fruit Set ◽  
Climatic Factors ◽  
Embryo Sac ◽  
Wine Industry ◽  
Nucleotide Polymorphisms ◽  
Wine Quality ◽  
Single Nucleotide ◽  
Germplasm Collections

Abstract Background Grapevine reproductive development has direct implications on yield. It also impacts on berry and wine quality by affecting traits like seedlessness, berry and bunch size, cluster compactness and berry skin to pulp ratio. Seasonal fluctuations in yield, fruit composition and wine attributes, which are largely driven by climatic factors, are major challenges for worldwide table grape and wine industry. Accordingly, a better understanding of reproductive processes such as gamete development, fertilization, seed and fruit set is of paramount relevance for managing yield and quality. With the aim of providing new insights into this field, we searched for clones with contrasting seed content in two germplasm collections. Results We identified eight variant pairs that seemingly differ only in seed-related characteristics while showing identical genotype when tested with the GrapeReSeq_Illumina_20K_SNP_chip and several microsatellites. We performed multi-year observations on seed and fruit set deriving from different pollination treatments, with special emphasis on the pair composed by Sangiovese and its seedless variant locally named Corinto Nero. The pollen of Corinto Nero failed to germinate in vitro and gave poor berry set when used to pollinate other varieties. Most berries from both open- and cross-pollinated Corinto Nero inflorescences did not contain seeds. The genetic analysis of seedlings derived from occasional Corinto Nero normal seeds revealed that the few Corinto Nero functional gametes are mostly unreduced. Moreover, three genotypes, including Sangiovese and Corinto Nero, were unexpectedly found to develop fruits without pollen contribution and occasionally showed normal-like seeds. Five missense single nucleotide polymorphisms were identified between Corinto Nero and Sangiovese from transcriptomic data. Conclusions Our observations allowed us to attribute a seedlessness type to some variants for which it was not documented in the literature. Interestingly, the VvAGL11 mutation responsible for Sultanina stenospermocarpy was also discovered in a seedless mutant of Gouais Blanc. We suggest that Corinto Nero parthenocarpy is driven by pollen and/or embryo sac defects, and both events likely arise from meiotic anomalies. The single nucleotide polymorphisms identified between Sangiovese and Corinto Nero are suitable for testing as traceability markers for propagated material and as functional candidates for the seedless phenotype.

scholarly journals Polymorphic Protective Dps–DNA Co-Crystals by Cryo Electron Tomography and Small Angle X-Ray Scattering

Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 39 ◽  
Author(s):  
Roman Kamyshinsky ◽  
Yury Chesnokov ◽  
Liubov Dadinova ◽  
Andrey Mozhaev ◽  
Ivan Orlov ◽  
...  
Keyword(s):  
Small Angle ◽  
Electron Tomography ◽  
Actual Structure ◽  
X Ray ◽  
Cell Parameters ◽  
X Ray Scattering ◽  
Cryo Electron Tomography ◽  
Dps Protein ◽  
Ray Scattering

Rapid increase of intracellular synthesis of specific histone-like Dps protein that binds DNA to protect the genome against deleterious factors leads to in cellulo crystallization—one of the most curious processes in the area of life science at the moment. However, the actual structure of the Dps–DNA co-crystals remained uncertain in the details for more than two decades. Cryo-electron tomography and small-angle X-ray scattering revealed polymorphous modifications of the co-crystals depending on the buffer parameters. Two different types of the Dps–DNA co-crystals are formed in vitro: triclinic and cubic. Three-dimensional reconstruction revealed DNA and Dps molecules in cubic co-crystals, and the unit cell parameters of cubic lattice were determined consistently by both methods.

scholarly journals Protective Dps–DNA co‐crystallization in stressed cells: an in vitro structural study by small‐angle X‐ray scattering and cryo‐electron tomography

FEBS Letters ◽  
2019 ◽  
Vol 593 (12) ◽  
pp. 1360-1371 ◽  
Author(s):  
Liubov A. Dadinova ◽  
Yurii M. Chesnokov ◽  
Roman A. Kamyshinsky ◽  
Ivan A. Orlov ◽  
Maxim V. Petoukhov ◽  
...  
Keyword(s):  
Structural Study ◽  
Small Angle ◽  
Electron Tomography ◽  
X Ray ◽  
X Ray Scattering ◽  
Cryo Electron Tomography ◽  
Stressed Cells ◽  
Ray Scattering

In-Silico and In-vitro Analysis of Human SOS1 Protein Causing Noonan Syndrome – A Novel Approach to Explore the Molecular Pathways

2021 ◽  
Vol 22 ◽  
Author(s):  
Vinoth Sigamani ◽  
Sheeja Rajasingh ◽  
Narasimman Gurusamy ◽  
Arunima Panda ◽  
Johnson Rajasingh
Keyword(s):  
Noonan Syndrome ◽  
In Silico ◽  
Genetic Disorder ◽  
In Vitro Study ◽  
Human Skin Fibroblast ◽  
Nucleotide Polymorphisms ◽  
Gene Expressions ◽  
Single Nucleotide ◽  
Nucleotide Mutation

Aims: Noonan syndrome (NS) is an autosomal dominant genetic disorder caused by single nucleotide mutation in PTPN11, SOS1, RAF1, and KRAS genes. Background: We hypothesize that in-silico analysis of human SOS1 mutations would be a promising predictor in identifying the pathogenic effect of NS. Methods: Here, we computationally analyzed the SOS1 gene to identify the pathogenic non-synonymous single nucleotide polymorphisms (nsSNPs) to cause NS. The variant information of SOS1 was collected from the SNP database (dbSNP). The variants were further analyzed by in-silico tools I-Mutant, iPTREE-STAB, and MutPred to elucidate their structural and functional characteristics. Results: We found that 11 nsSNPs of SOS1 were more pathogenic to cause NS. The 3D modeling of the wild-type and the 11 nsSNPs were performed using I-TASSER and validated via ERRAT and RAMPAGE. SOS1 interacting proteins were analysed through STRING, which showed that SOS1 interacted with cardiac proteins GATA4, TNNT2, and ACTN2. During these interactions, GRB2 and HRAS act as an intermediate molecules between SOS1 and cardiac proteins. These in-silico analyses were validated using induced cardiomyocytes (iCMCs) derived from NS patients carrying SOS1 gene variant c.1654A>G (NS-iCMCs) and compared with control human skin fibroblast-derived iCMCs (C-iCMCs). Our in vitro data further confirmed that the SOS1, GRB2 and HRAS gene expressions as well as the activated ERK protein, were significantly decreased in NS-iCMCs compared to C-iCMCs. Conclusion: This is the first in-silico and in vitro study demonstrating that 11 nsSNPs of SOS1 were playing a deleterious pathogenic role in causing NS.

Contribution of boars to reproductive performance and paternity after homospermic and heterospermic artificial insemination

2015 ◽  
Vol 27 (7) ◽  
pp. 1012 ◽  
Author(s):  
C. E. R. Ferreira ◽  
D. B. Sávio ◽  
A. C. Guarise ◽  
M. J. Flach ◽  
G. D. A. Gastal ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Artificial Insemination ◽  
Penetration Rate ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Blood Samples ◽  
Precise Evaluation ◽  
Umbilical Cords ◽  
Farrowing Rate

Heterospermic AI is commonly used in swine despite preventing precise evaluation of individual boar fertility. The present study compared the contribution of four boars (A, B, C and D) for reproductive performance and for paternity using homospermic and heterospermic (AB, AC, AD, BC, BD and CD) AI (n = 204 for homospermic AI; n = 307 for heterospermic AI). Blood samples from the four boars, from all sows inseminated with heterospermic doses and from the umbilical cords of their piglets, as well as tissue smears from mummified fetuses, were genotyped using single nucleotide polymorphisms (SNPs). Differences among boars were detected for the in vitro oocyte penetration rate and for the number of spermatozoa per oocyte (P < 0.05), but not for sperm motility, mitochondrial functionality and integrity of the membrane, acrosome and DNA (P > 0.05). Homospermic and heterospermic AI resulted in similar (P > 0.05) farrowing rates (90.5% and 89.9%, respectively) and total litter size (12.4 ± 0.4 and 12.7 ± 0.7, respectively). Farrowing rate was lower for Boar B than for Boar C (P < 0.05), but no other differences in reproductive performance among boars were observed with homospermic AI. The SNPs determined the paternity of 94.2% of the piglets sired by heterospermic AI. In the AC pool, paternity contribution per boar was similar (P > 0.05), but differences between boars occurred in all other pools (P < 0.05). Boar D achieved the greatest paternity contribution in all pools and parity categories (nearly 60%), whereas Boar B sired the fewest piglets (at most 40%). Reproductive performance was similar with homospermic and heterospermic AI, but differences in performance among boars undetected with homospermic AI were only evident after genotyping the piglets sired through heterospermic AI.

scholarly journals Decellularized pericardium tissues at increasing glucose, galactose and ribose concentrations and at different time points studied using scanning X-ray microscopy

IUCrJ ◽  
2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Cinzia Giannini ◽  
Liberato De Caro ◽  
Alberta Terzi ◽  
Luca Fusaro ◽  
Davide Altamura ◽  
...  
Keyword(s):  
Molecular Level ◽  
Wide Angle ◽  
Collagen Structure ◽  
Tissue Samples ◽  
X Ray ◽  
X Ray Scattering ◽  
Aging Populations ◽  
Secondary Diseases

Diseases like widespread diabetes or rare galactosemia may lead to high sugar concentrations in the human body, thereby promoting the formation of glycoconjugates. Glycation of collagen, i.e. the formation of glucose bridges, is nonenzymatic and therefore cannot be prevented in any other way than keeping the sugar level low. It relates to secondary diseases, abundantly occurring in aging populations and diabetics. However, little is known about the effects of glycation of collagen on the molecular level. We studied in vitro the effect of glycation, with D-glucose and D-galactose as well as D-ribose, on the structure of type 1 collagen by preparing decellularized matrices of bovine pericardia soaked in different sugar solutions, at increasing concentrations (0, 2.5, 5, 10, 20 and 40 mg ml−1), and incubated at 37°C for 3, 14, 30 and 90 days. The tissue samples were analyzed with small- and wide-angle X-ray scattering in scanning mode. We found that glucose and galactose produce similar changes in collagen, i.e. they mainly affect the lateral packing between macromolecules. However, ribose is much faster in glycation, provoking a larger effect on the lateral packing, but also seems to cause qualitatively different effects on the collagen structure.

scholarly journals Direct Correlation Between Ligand-Induced α-Synuclein Oligomers and Amyloid-like Fibril Growth

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Martin Nors Pedersen ◽  
Vito Foderà ◽  
Istvan Horvath ◽  
Andreas van Maarschalkerweerd ◽  
Katrine Nørgaard Toft ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Small Angle ◽  
Alpha Synuclein ◽  
X Ray ◽  
Transient Nature ◽  
X Ray Scattering ◽  
Amyloid Deposits ◽  
Potential Link ◽  
Presence And Absence

Abstract Aggregation of proteins into amyloid deposits is the hallmark of several neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. The suggestion that intermediate oligomeric species may be cytotoxic has led to intensified investigations of pre-fibrillar oligomers, which are complicated by their transient nature and low population. Here we investigate alpha-synuclein oligomers, enriched by a 2-pyridone molecule (FN075) and the conversion of oligomers into fibrils. As probed by leakage assays, the FN075 induced oligomers potently disrupt vesicles in vitro, suggesting a potential link to disease related degenerative activity. Fibrils formed in the presence and absence of FN075 are indistinguishable on microscopic and macroscopic levels. Using small angle X-ray scattering, we reveal that FN075 induced oligomers are similar, but not identical, to oligomers previously observed during alpha-synuclein fibrillation. Since the levels of FN075 induced oligomers correlate with the amounts of fibrils among different FN075:protein ratios, the oligomers appear to be on-pathway and modeling supports an ‘oligomer stacking model’ for alpha-synuclein fibril elongation.

scholarly journals Single-Nucleotide-Polymorphism-Specific PCR for Quantification and Discrimination of Chlamydia pneumoniae Genotypes by Use of a “Locked” Nucleic Acid

2006 ◽  
Vol 72 (5) ◽  
pp. 3785-3787 ◽  
Author(s):  
Jan Rupp ◽  
Werner Solbach ◽  
Jens Gieffers
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Chlamydia Pneumoniae ◽  
Locked Nucleic Acid ◽  
Nucleotide Polymorphisms ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Specific Pcr ◽  
Intraspecies Diversity

ABSTRACT Single-nucleotide polymorphisms (SNPs) are targets to discriminate intraspecies diversity of bacteria and to correlate a genotype with a potential pathotype. Quantification of polygenotypic populations supports this task for in vitro and in vivo applications. We present a novel assay capable of quantifying mixtures of two genotypes differing by only one SNP.

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