scholarly journals Toxin Inactivation in Toxin/Antitoxin Systems

2019 ◽  
Author(s):  
Laura Fernandez-Garcia ◽  
Jun-Seob Kim ◽  
Maria Tomas ◽  
Thomas K. Wood
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Metabolic Activity ◽  
Type I ◽  
Type Ii ◽  
Genetic Elements ◽  
Type V ◽  
Chromosomal Mutations

Toxin/antitoxin (TA) systems are used primarily to inhibit phage, reduce metabolic activity during stress, and maintain genetic elements. Given the extreme toxicity of some of the toxins of these TA systems, we were curious how the cell silences toxins, if the antitoxin is inactivated or when toxins are obtained without antitoxins via horizontal gene transfer. Here we find that the RalR (type I), MqsR (type II), GhoT (type V), and Hha (type VII) toxins are inactivated primarily by a mutation that inactivates the toxin promoter or via the chromosomal mutations iraM and mhpR.

Chaperones and protein folding in the archaea

2009 ◽  
Vol 37 (1) ◽  
pp. 46-51 ◽  
Author(s):  
Andrew T. Large ◽  
Martin D. Goldberg ◽  
Peter A. Lund
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Heat Shock Protein ◽  
Haloferax Volcanii ◽  
Functional Specialization ◽  
Type I ◽  
Type Ii ◽  
Shock Proteins

A survey of archaeal genomes for the presence of homologues of bacterial and eukaryotic chaperones reveals several interesting features. All archaea contain chaperonins, also known as Hsp60s (where Hsp is heat-shock protein). These are more similar to the type II chaperonins found in the eukaryotic cytosol than to the type I chaperonins found in bacteria, mitochondria and chloroplasts, although some archaea also contain type I chaperonin homologues, presumably acquired by horizontal gene transfer. Most archaea contain several genes for these proteins. Our studies on the type II chaperonins of the genetically tractable archaeon Haloferax volcanii have shown that only one of the three genes has to be present for the organisms to grow, but that there is some evidence for functional specialization between the different chaperonin proteins. All archaea also possess genes for prefoldin proteins and for small heat-shock proteins, but they generally lack genes for Hsp90 and Hsp100 homologues. Genes for Hsp70 (DnaK) and Hsp40 (DnaJ) homologues are only found in a subset of archaea. Thus chaperone-assisted protein folding in archaea is likely to display some unique features when compared with that in eukaryotes and bacteria, and there may be important differences in the process between euryarchaea and crenarchaea.

scholarly journals Discovery of widespread type I and type V CRISPR-Cas inhibitors

Science ◽  
2018 ◽  
Vol 362 (6411) ◽  
pp. 240-242 ◽  
Author(s):  
Nicole D. Marino ◽  
Jenny Y. Zhang ◽  
Adair L. Borges ◽  
Alexander A. Sousa ◽  
Lina M. Leon ◽  
...  
Keyword(s):  
Immune Function ◽  
Broad Spectrum ◽  
Mobile Genetic Elements ◽  
Mobile Elements ◽  
Human Cells ◽  
Type I ◽  
Type Ii ◽  
Genetic Elements ◽  
Type V

Bacterial CRISPR-Cas systems protect their host from bacteriophages and other mobile genetic elements. Mobile elements, in turn, encode various anti-CRISPR (Acr) proteins to inhibit the immune function of CRISPR-Cas. To date, Acr proteins have been discovered for type I (subtypes I-D, I-E, and I-F) and type II (II-A and II-C) but not other CRISPR systems. Here, we report the discovery of 12 acr genes, including inhibitors of type V-A and I-C CRISPR systems. AcrVA1 inhibits a broad spectrum of Cas12a (Cpf1) orthologs—including MbCas12a, Mb3Cas12a, AsCas12a, and LbCas12a—when assayed in human cells. The acr genes reported here provide useful biotechnological tools and mark the discovery of acr loci in many bacteria and phages.

scholarly journals Native Gold in the Chudnoe Au-Pd-REE Deposit (Subpolar Urals, Russia): Composition, Minerals in Intergrowth and Genesis

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 451
Author(s):  
Galina Palyanova ◽  
Valery Murzin ◽  
Andrey Borovikov ◽  
Nikolay Karmanov ◽  
Sergei Kuznetsov
Keyword(s):  
Native Gold ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Gold Mineralization ◽  
Type I ◽  
Type Ii ◽  
Subpolar Urals ◽  
Type V ◽  
Impurity Elements

Composition of native gold and minerals in intergrowth with rhyolites of the Chudnoe Au-Pd-REE deposit (Subpolar Urals, Russia) was studied using optical microscopy, scanning electron microscopy, and electron microprobe analysis. Five varieties of native gold have been identified, based on the set of impurity elements and their quantities, and on intergrown minerals. Native gold in rhyolites from the Ludnaya ore zone is homogeneous and contains only Ag (fineness 720‰, type I). It is in intergrowth with fuchsite or allanite and mertieite-II. In rhyolites from the Slavnaya ore zone, native gold is heterogeneous, has a higher fineness, different sets and contents of elements: Ag, Cu, 840–860‰ (type II); Ag, Cu, Pd, 830–890‰ (III); Ag, Pd, Cu, Hg, 840–870‰ (IV). It occurs in intergrowth with fuchsite, albite, and mertieite-II (type II), or albite, quartz, and atheneite (III), or quartz, albite, K-feldspar, and mertieite-II (IV). High fineness gold (930–1000‰, type V) with low contents of Ag, Cu, and Pd or their absence occurs in the form as microveins, fringes and microinclusions in native gold II–IV. Tetra-auricupride (AuCu) is presented as isometric inclusions in gold II and platelets in the decay structures in gold III and IV. The preliminary data of a fluid inclusions study showed that gold mineralization at the Chudnoe deposit could have been formed by chloride fluids of low and medium salinity at temperatures from 105 to 230 °C and pressures from 5 to 115 MPa. The formation of native gold I is probably related to fuchsitization and allanitization of rhyolites. The formation of native gold II-V is also associated with the same processes, but it is more complicated and occurred later with a significant role of Na-, Si-, and K-metasomatism. The presence of Pd and Cu in the ores and Cr in fuchsite indicates the important role of mafic-ultramafic magmatism.

scholarly journals A mobile genetic element increases bacterial host fitness by manipulating development

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Joshua M Jones ◽  
Ilana Grinberg ◽  
Avigdor Eldar ◽  
Alan D Grossman
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Mobile Genetic Elements ◽  
Selective Advantage ◽  
Host Cells ◽  
Bacterial Host ◽  
Host Fitness ◽  
Genetic Elements ◽  
Necessary And Sufficient ◽  
Integrative And Conjugative Element

Horizontal gene transfer is a major force in bacterial evolution. Mobile genetic elements are responsible for much of horizontal gene transfer and also carry beneficial cargo genes. Uncovering strategies used by mobile genetic elements to benefit host cells is crucial for understanding their stability and spread in populations. We describe a benefit that ICEBs1, an integrative and conjugative element of Bacillus subtilis, provides to its host cells. Activation of ICEBs1 conferred a frequency-dependent selective advantage to host cells during two different developmental processes: biofilm formation and sporulation. These benefits were due to inhibition of biofilm-associated gene expression and delayed sporulation by ICEBs1-containing cells, enabling them to exploit their neighbors and grow more prior to development. A single ICEBs1 gene, devI (formerly ydcO), was both necessary and sufficient for inhibition of development. Manipulation of host developmental programs allows ICEBs1 to increase host fitness, thereby increasing propagation of the element.

scholarly journals Distribution of Virulence Genes Among Methicillin-resistant Staphylococcus Aureus of Clinical and Environmental Origin

2020 ◽  
Author(s):  
Deepshikha Bhowmik ◽  
Shiela Chetri ◽  
Bhaskar Jyoti Das ◽  
Debadatta Dhar Chanda ◽  
Amitabha Bhattacharjee
Keyword(s):  
Staphylococcus Aureus ◽  
Multidrug Resistance ◽  
Virulence Genes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Virulence Gene ◽  
Type I ◽  
Type Ii ◽  
Methicillin Resistant ◽  
Type Iv ◽  
Type V

Abstract Objective: This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical and environmental settings. Results: The virulence gene such as sea (n=54), seb (n=21), eta (n=27), etb (n=2), cna (n=24), ica (n=2) and tst (n=30) was revealed from this study. Different SCCmec types such as type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII were detected among sixty three MRSA isolates where SCCmec type II having ST1551 and type V with ST2416 were found to be associated with multidrug resistance and were highly prevalent in the study area.

The gene transfer of soluble VEGF type I receptor (Flt-1) attenuates peritoneal fibrosis formation in mice but not soluble TGF-β type II receptor gene transfer

2005 ◽  
Vol 288 (1) ◽  
pp. G143-G150 ◽  
Author(s):  
Y. Motomura ◽  
H. Kanbayashi ◽  
W. I. Khan ◽  
Y. Deng ◽  
P. A. Blennerhassett ◽  
...  
Keyword(s):  
Growth Factor ◽  
Gene Transfer ◽  
Negative Correlation ◽  
Significant Negative Correlation ◽  
Receptor Type ◽  
Type I ◽  
Type Ii ◽  
Collagen Deposition ◽  
Significant Elevation ◽  
Peritoneal Fibrosis

Peritoneal fibrosis formation is a consequence of inflammation/injury and a significant medical problem to be solved. The effects of soluble VEGF receptor type I (sFlt-1) gene transfer on experimental peritoneal fibrosis were examined and compared with soluble transforming growth factor-β (TGF-β) receptor type II (sTGFβRII) gene transfer. Male C57BL/6 mice were injected with 1.5 × 108plaque-forming unit of adenovirus encoding active TGF-β (AdTGFβ) intraperitoneally. Some mice had been treated with sTGFβRII or sFlt-1 plasmid injection into skeletal muscle with electroporation 4 days before virus administration. Mice were euthanized at day 14 after virus administration. AdTGFβ induced significant elevation of serum active TGF-β, caused significant inflammatory response [weight loss, elevation of serum amyloid-P (SAP) and IL-12, increased expression of monocyte chemoattractant protein-1 (MCP-1) mRNA], and induced marked thickening of the peritoneum and collagen deposition. Gene transfer of sFlt-1 reduced the collagen deposition ∼81% in mesenteric tissue. Treatment with sFlt-1 decreased ICAM-1 and MCP-1 mRNA expression significantly. Significant negative correlation between serum sFlt-1 and placental growth factor level was observed, whereas there was no significant negative correlation between sFlt-1 and VEGF. On the other hand, sTGFβRII treatment enhanced the AdTGFβ-induced inflammation (significant elevation of SAP, TNF-α, and IL-12 levels and upregulation of ICAM-1 and MCP-1 mRNA expressions) and failed to prevent collagen deposition. These observations indicate that sFlt-1 gene transfer might be of therapeutic benefit in peritoneal fibrosis.

Syntheses of Post-Iboga Alkaloids

Synthesis ◽  
2019 ◽  
Vol 51 (14) ◽  
pp. 2737-2758 ◽  
Author(s):  
Hyeonggeun Lim ◽  
Sikwang Seong ◽  
Sunkyu Han
Keyword(s):  
Secondary Metabolites ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Type Iv ◽  
Synthetic Studies ◽  
Type V

Post-iboga alkaloids are secondary metabolites that are biosynthetically derived from iboga-type alkaloids via rearrangements of the indole and/or isoquinuclidine moieties. Herein, we categorize post-iboga alkaloids into five types based on the biosynthetic mode of transformation of the iboga scaffold. We then describe reported syntheses of post-iboga alkaloids, including our laboratory’s recent contributions, based on our own categorization.1 Introduction1.1 Iboga and Post-Iboga Alkaloids1.2 Classification of Post-Iboga Alkaloids1.2.1 Introduction to Type I Post-Iboga Alkaloids1.2.2 Introduction to Type II Post-Iboga Alkaloids1.2.3 Introduction to Type III Post-Iboga Alkaloids1.2.4 Introduction to Type IV Post-Iboga Alkaloids1.2.5 Introduction to Type V Post-Iboga Alkaloids2 Syntheses of Post-Iboga Alkaloids2.1 Syntheses of Type I Post-Iboga Alkaloids2.1.1 Syntheses of Monomeric Type I Post-Iboga Alkaloids2.1.2 Syntheses of Dimeric Type I Post-Iboga Alkaloids2.2 Syntheses of Type II Post-Iboga Alkaloids2.3 Synthetic Studies Toward Type III Post-Iboga Alkaloids2.4 Syntheses of Type IV Post-Iboga Alkaloids2.5 Synthesis of Type V Post-Iboga Alkaloids3 Conclusion and Outlook

scholarly journals Biomechanical Impact of FHL Tendon Harvest on Forefoot and Great Toe Push-off Strength and Its Correlation to Knot of Henry Crossover Variation

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0003
Author(s):  
Timothy Charlton ◽  
Danielle Thomas ◽  
David Thordarson ◽  
Melodie Metzger ◽  
Trevor Nelson
Keyword(s):  
Repeated Measures ◽  
Plantar Flexion ◽  
Tissue Bank ◽  
Flexor Hallucis Longus ◽  
Type I ◽  
Type Ii ◽  
Great Toe ◽  
Type Iv ◽  
Loading Patterns ◽  
Type V

Category: Midfoot/Forefoot Introduction/Purpose: The flexor hallucis longus (FHL) tendon is commonly used for tendon transfers in reconstructive Achilles tendon procedures. A subset of patients who undergo this procedure complain of first great toe weakness and loss of push off strength after FHL tendon transfer. Despite the frequency of this procedure, there is currently little information available to surgeons to help understand this potential complication. Therefore, the objective of this biomechanical cadaveric study was to quantify plantar flexion strength after FHL harvest and correlate it to variations in anatomy to determine if distinct tendon crossover patterns at the Knot of Henry are more likely to lead to forefoot weakness. Methods: Cadaveric specimens were procured from an approved tissue bank. The proximal end of the tibia was potted and secured to the Mechanical Testing System. A pressure mapping system was used to measure plantar force though the great toe and lesser toes. The Achilles, FHL, and flexor digitorum longus (FDL) tendons were attached to linear actuators for load application. Pressure under the toes was measured with the Achilles alone, Achilles with FHL, Achilles with FDL, and Achilles with both FHL and FDL. The resultant loading patterns were recorded in the greater and lesser toes and compared between the different states. After biomechanical testing, all specimens were carefully dissected and the tendinous slips between the FHL and FDL were documented and classified based on a previously determined system (Types I-V, LaRue; Edama) Functional and anatomical relationship between the classification type and loading patterns were statistically analyzed using repeated measures ANOVA. Results: 23 specimens (13M / 10F) with a mean age of 71 years (range: 54-90) were used in this study. 61% were anatomically classified as type I, followed by type II (26%), IV (9%), and type V (4%), and type III (0%). Simulated FHL harvest in type I specimens resulted in a 29% decrease in great toe flexion pressure and an 21% decrease in total forefoot flexion pressure, p<0.05. In type II feet, FHL harvest led to a greater reduction in flexion pressure in the great toe (34%) and forefoot (25%), p<0.05. Type IV specimens also had a decrease in flexion pressure in both the great toe (21%) and forefoot (15%), p<0.05. Type V specimens trended similar to type I specimens. Conclusion: This study is the first to quantify loss of great toe and lesser toe flexion pressure after FHL harvest. In addition, it is the first to correlate these losses to variations in anatomic crossover patterns at the Knot of Henry. Specimens classified as type II had the greatest reduction in flexion pressure, followed by type I and type IV. This information is clinically important for preoperative discussions about post-surgical expectations and surgical planning.

Adenoviral mediated gene transfer of PDGF-B enhances wound healing in type I and type II diabetic wounds

2004 ◽  
Vol 12 (5) ◽  
pp. 497-504 ◽  
Author(s):  
Sundeep G. Keswani ◽  
Anna B. Katz ◽  
Foong-Yen Lim ◽  
Philip Zoltick ◽  
Antoneta Radu ◽  
...  
Keyword(s):  
Wound Healing ◽  
Gene Transfer ◽  
Type I ◽  
Type Ii ◽  
Diabetic Wounds
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