Mutations and Rearrangements in the Genome of Sulfolobus solfataricus P2

ABSTRACT The genome of Sulfolobus solfataricus P2 carries a larger number of transposable elements than any other sequenced genome from an archaeon or bacterium and, as a consequence, may be particularly susceptible to rearrangement and change. In order to gain more insight into the natures and frequencies of different types of mutation and possible rearrangements that can occur in the genome, the pyrEF locus was examined for mutations that were isolated after selection with 5-fluoroorotic acid. About two-thirds of the 130 mutations resulted from insertions of mobile elements, including insertion sequence (IS) elements and a single nonautonomous mobile element, SM2. For each of these, the element was identified and shown to be present at its original genomic position, consistent with a progressive increase in the copy numbers of the mobile elements. In addition, several base pair substitutions, as well as small deletions, insertions, and a duplication, were observed, and about one-fifth of the mutations occurred elsewhere in the genome, possibly in an orotate transporter gene. One mutant exhibited a 5-kb genomic rearrangement at the pyrEF locus involving a two-step IS element-dependent reaction, and its boundaries were defined using a specially developed “in vitro library” strategy. Moreover, while searching for the donor mobile elements, evidence was found for two major changes that had occurred in the genome of strain P2, one constituting a single deletion of about 4% of the total genome (124 kb), while the other involved the inversion of a 25-kb region. Both were bordered by IS elements and were inferred to have arisen through recombination events. The results underline the caution required in working experimentally with an organism such as S. solfataricus with a continually changing genome.

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Shuffling of Sulfolobus genomes by autonomous and non-autonomous mobile elements

Biochemical Society Transactions ◽

10.1042/bst0320179 ◽

2004 ◽

Vol 32 (2) ◽

pp. 179-183 ◽

Cited By ~ 44

Author(s):

K. Brügger ◽

E. Torarinsson ◽

P. Redder ◽

L. Chen ◽

R.A. Garrett

Keyword(s):

Experimental Data ◽

Insertion Sequence ◽

Sulfolobus Solfataricus ◽

Mobile Element ◽

Mobile Elements ◽

Sulfolobus Tokodaii ◽

Is Elements ◽

Large Numbers ◽

Sequence Elements ◽

Insertion Sequence Elements

Each of the sequenced Sulfolobus genomes contains large numbers of putatively mobile elements, both IS elements (insertion sequence elements) and MITEs (miniature inverted-repeat transposable elements). There are 344 in the 3.0 Mb genome of Sulfolobus solfataricus P2 and 95 in the 2.7 Mb genome of Sulfolobus tokodaii. In the former they constitute more than 10% of the genome. Experimental data suggest that transposition of IS elements occurs frequently. Moreover, the gene order between the two organisms differs greatly, indicating that multiple rearrangements have occurred. This has also led to considerable speculation as to how the cells are viable. Recently, a third Sulfolobus genome was completed which contains no IS elements or MITEs. This enabled us to compare the gene orders of the three genomes and provide evidence for mobile element-induced rearrangements of sections of the genomes.

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Hierarchical Assembly Pathways of Spermine Induced Tubulin Conical-Spiral Architectures

10.26434/chemrxiv.11353166 ◽

2020 ◽

Author(s):

Raviv Dharan ◽

Asaf Shemesh ◽

Abigail Millgram ◽

Yael Levi-Kalisman ◽

Israel Ringel ◽

...

Keyword(s):

Progressive Increase ◽

Hexagonal Symmetry ◽

Time Resolved ◽

Hierarchical Assembly ◽

X Ray Scattering ◽

Cellular Factors ◽

Hierarchical Architectures ◽

Assembly Pathways ◽

Insight Into

<p>Tubulin, an essential cytoskeletal protein, assembles into various morphologies by interacting with cellular factors. Spermine, an endogenous polyamine, promotes and stabilizes tubulin assemblies. Yet, the assembled structures and their formation pathways are poorly known. Here we show that spermine induced tubulin to assemble <i>in vitro</i> into hierarchical architectures, based on a tubulin conical-spiral (TCS) subunit. Using solution X-ray scattering and cryo-TEM, we showed that with progressive increase of spermine concentration, tubulin-dimers assembled into a tubulin helical-pitch (or a short TCS), TCSs, TCS that stacked into tubes through base-to-top packing, antiparallel bundles of TCS tubes in a quasi-hexagonal symmetry, and eventually twisted hexagonal bundles of inverted tubulin tubules. Time-resolved experiments revealed that tubulin assemblies formed at low spermine concentrations were precursors of the assemblies formed at higher spermine concentrations. The results provide insight into the variety of morphologies that tubulin can form, and contribute to our understanding of the fundamental interactions that control the composition and construction of protein-based biomaterials.</p>

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Genomic characterization of IncpA1763-KPC: IncFIIK7 type plasmids p13294-KPC and pA1966-NR from Klebsiella pneumoniae

Future Microbiology ◽

10.2217/fmb-2020-0026 ◽

2020 ◽

Vol 15 (9) ◽

pp. 713-721

Author(s):

Qifeng Sun ◽

Jiao Feng ◽

Yigang Tong ◽

Luhua Liang ◽

Fei Zhai ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Klebsiella Pneumoniae ◽

Resistance Gene ◽

Resistance Genes ◽

Genomic Analysis ◽

Mobile Elements ◽

Is Elements ◽

Genomic Characterization ◽

Insight Into

Aim: To characterize two plasmids p13294-KPC and pA1966-NR from clinical Klebsiella pneumoniae strains. Materials & methods: Plasmids p13294-KPC and pA1966-NR were fully sequenced and then detailed genomic analysis was performed in this work. The antimicrobial resistance phenotypes were determined. Results: p13294-KPC and pA1966-NR displayed IncpA1763-KPC:IncFIIK7 dual-replicon structures. The backbone of these two plasmids were closely related to each other. p13294-KPC contained two accessory modules, namely ΔIS Kpn25 and blaKPC-2 region, and the blaKPC-2 region carried a range of mobile elements and resistance gene blaKPC-2. while pA1966-NR contained four individual IS elements in its backbone and carried no resistance genes. Conclusion: This study provided a deeper insight into the genomic characterization of IncpA1763-KPC: IncFIIK7 type plasmids p13294-KPC and pA1966-NR.

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Geographic Distribution of a Large Mobile Element That Transfers Ampicillin and Vancomycin Resistance betweenEnterococcus faecium Strains

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.5.1349-1351.2000 ◽

2000 ◽

Vol 44 (5) ◽

pp. 1349-1351 ◽

Cited By ~ 29

Author(s):

Jennifer Hanrahan ◽

Claudia Hoyen ◽

Louis B. Rice

Keyword(s):

United States ◽

Geographic Distribution ◽

Enterococcus Faecium ◽

Mobile Element ◽

The United States ◽

Mobile Elements ◽

Physical Relationship ◽

Ampicillin Resistance ◽

Vancomycin Resistant

ABSTRACT In several clonally unrelated VanB-type vancomycin-resistantEnterococcus faecium strains, we demonstrated a common physical relationship between pbp5 and Tn5382as well as common mutations within pbp5. The majority of these strains transferred vancomycin and ampicillin resistance toE. faecium in vitro, suggesting the dissemination of similar transferable pbp5-vanB-containing mobile elements throughout the United States.

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Hierarchical Assembly Pathways of Spermine Induced Tubulin Conical-Spiral Architectures

10.26434/chemrxiv.11353166.v2 ◽

2020 ◽

Author(s):

Raviv Dharan ◽

Asaf Shemesh ◽

Abigail Millgram ◽

Yael Levi-Kalisman ◽

Israel Ringel ◽

...

Keyword(s):

Progressive Increase ◽

Hexagonal Symmetry ◽

Time Resolved ◽

Hierarchical Assembly ◽

X Ray Scattering ◽

Cellular Factors ◽

Hierarchical Architectures ◽

Assembly Pathways ◽

Insight Into

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The crosstalk between autophagy and apoptosis was mediated by phosphorylation of Bcl-2 and beclin1 in benzene-induced hematotoxicity

Cell Death and Disease ◽

10.1038/s41419-019-2004-4 ◽

2019 ◽

Vol 10 (10) ◽

Cited By ~ 6

Author(s):

Yujiao Chen ◽

Wei Zhang ◽

Xiaoli Guo ◽

Jing Ren ◽

Ai Gao

Keyword(s):

Risk Assessment ◽

Molecular Mechanisms ◽

Ros Generation ◽

Hematological Cancer ◽

Exposed Workers ◽

Different Types ◽

First Time ◽

The Relationship ◽

Insight Into

Abstract Increasing evidence suggested that benzene exposure resulted in different types of hematological cancer. Both autophagy and apoptosis were reported to play vital roles in benzene toxicity, but the relationship between autophagy and apoptosis remain unclear in benzene-induced hematotoxicity. In this study, the toxic effect of benzene on autophagy and apoptosis in benzene-exposed workers and in vitro were verified. Results showed that benzene metabolite (1, 4-benzoquinone, 1, 4-BQ) dose-dependently induced autophagy and apoptosis via enhancing phosphorylation of Bcl-2 and beclin1. Finally, we also found that the elevated ROS was in line with enhancing the phosphorylation of Bcl-2 and beclin1 which contributed to 1, 4-BQ-induced autophagy and apoptosis. Taken together, this study for the first time found that the effect of 1, 4-BQ on the crosstalk between autophagy and apoptosis were modulated by the ROS generation via enhancing phosphorylation of Bcl-2(Ser70) and phosphorylation of beclin1(Thr119), which offered a novel insight into underlying molecular mechanisms of benzene-induced hematotoxicity, and specifically how the crosstalk between autophagy and apoptosis was involved in benzene toxicity. This work provided novel evidence for the toxic effects and risk assessment of benzene.

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Insight into Neutrophil Extracellular Traps through Systematic Evaluation of Citrullination and Peptidylarginine Deiminases

Journal of Immunology Research ◽

10.1155/2019/2160192 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 9

Author(s):

Caitlyn L. Holmes ◽

Daeun Shim ◽

John Kernien ◽

Chad J. Johnson ◽

Jeniel E. Nett ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Neutrophil Extracellular Traps ◽

Systematic Evaluation ◽

Peptidylarginine Deiminase ◽

Monosodium Urate ◽

Extracellular Traps ◽

Different Types ◽

Citrullinated Proteins ◽

Insight Into

In rheumatoid arthritis, an autoimmune inflammatory arthritis, citrullinated proteins are targeted by autoantibodies and thus thought to drive disease. Neutrophil extracellular traps (NETs) are a source of citrullinated proteins and are increased in rheumatoid arthritis and therefore also implicated in disease pathogenesis. However, not all NETs are citrullinated. One theory aiming to clarify the intersection of citrullination, NETs, and rheumatoid arthritis suggests that specific stimuli induce different types of NETs defined by citrullination status. However, most studies do not evaluate uncitrullinated NETs, only citrullinated or total NETs. Further, the requirement for peptidylarginine deiminase (PAD) 2 and 4, two important citrullinating enzymes in neutrophils and rheumatoid arthritis, in the formation of different NETs has not been clearly defined. To determine if specific stimulants induce citrullinated or uncitrullinated NETs and if those structures require PAD2 or PAD4, human and murine neutrophils, including from PAD4-/- and PAD2-/- mice, were stimulated in vitro and NETs imaged and quantified. In humans, phorbol myristate acetate (PMA), ionomycin, monosodium urate (MSU), and Candida albicans induced NETs with MSU and C. albicans inducing primarily citrullinated, PMA primarily uncitrullinated, and ionomycin a mix of NETs. Only ionomycin and C. albicans were strong inducers of NETs in mice with ionomycin-induced NETs mostly citrullinated and C. albicans-induced NETs a mix of citrullinated and uncitrullinated. Interestingly, no stimulus induced exclusively citrullinated or uncitrullinated NETs. Further, PAD4 was required for citrullinated NETs only, whereas PAD2 was not required for either NET in mice. Therefore, specific stimuli induce varying proportions of both citrullinated and uncitrullinated NETs with different requirements for PAD4. These findings highlight the complexity of NET formation and the need to further define the mechanisms by which different NETs form and their implications for autoimmune disease.

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Ultrastructural Investigations of the Contractile Filaments of Amoebae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050950 ◽

1974 ◽

Vol 32 ◽

pp. 188-189

Author(s):

P.L. Moore

Keyword(s):

Cytoplasmic Streaming ◽

Three Dimensional ◽

Freeze Fracture ◽

Amoeboid Movement ◽

Different Types ◽

Chemical Conditions ◽

Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

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Recent Advances in Curcumin Nanocarriers for the Treatment of Different Types of Cancer with Special Emphasis on In Vitro Cytotoxicity and Cellular Uptake Studies

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681209666190417144126 ◽

2020 ◽

Vol 10 (5) ◽

pp. 577-590

Author(s):

Jai B. Sharma ◽

Shailendra Bhatt ◽

Asmita Sharma ◽

Manish Kumar

Keyword(s):

Cancer Cells ◽

Cellular Uptake ◽

Anticancer Agents ◽

Targeted Delivery ◽

In Vitro Cytotoxicity ◽

Curcumin Nanoparticles ◽

Cytotoxicity Studies ◽

Delivery Technique ◽

Different Types

Background: The potential use of nanocarriers is being explored rapidly for the targeted delivery of anticancer agents. Curcumin is a natural polyphenolic compound obtained from rhizomes of turmeric, belongs to family Zingiberaceae. It possesses chemopreventive and chemotherapeutic activity with low toxicity in almost all types of cancer. The low solubility and bioavailability of curcumin make it unable to use for the clinical purpose. The necessity of an effective strategy to overcome the limitations of curcumin is responsible for the development of its nanocarriers. Objective: This study is aimed to review the role of curcumin nanocarriers for the treatment of cancer with special emphasis on cellular uptake and in vitro cytotoxicity studies. In addition to this, the effect of various ligand conjugated curcumin nanoparticles on different types of cancer was also studied. Methods: A systematic review was conducted by extensively surfing the PubMed, science direct and other portals to get the latest update on recent development in nanocarriers of curcumin. Results: The current data from recent studies showed that nanocarriers of curcumin resulted in the targeted delivery, higher efficacy, enhanced bioavailability and lower toxicity. The curcumin nanoparticles showed significant inhibitory effects on cancer cells as compared to free curcumin. Conclusion: It can be concluded that bioavailability of curcumin and its cytotoxic effect to cancer cells can be enhanced by the development of curcumin based nanocarriers and it was found to be a potential drug delivery technique for the treatment of cancer.

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