Charge neutralization of lysine via carbamylation reveals hidden aggregation hot‐spots in tau protein flanking regions

FEBS Journal ◽  
2021 ◽  
Author(s):  
Joshna Gadhavi ◽  
Sumedha Shah ◽  
Tulika Sinha ◽  
Alok Jain ◽  
Sharad Gupta
Keyword(s):  
Tau Protein ◽  
Hot Spots ◽  
Charge Neutralization ◽  
Flanking Regions

scholarly journals Transfer of Vancomycin Resistance Transposon Tn1549 from Clostridium symbiosum to Enterococcus spp. in the Gut of Gnotobiotic Mice

2006 ◽  
Vol 50 (3) ◽  
pp. 1054-1062 ◽  
Author(s):  
Aline Launay ◽  
Susan A. Ballard ◽  
Paul D. R. Johnson ◽  
M. Lindsay Grayson ◽  
Thierry Lambert
Keyword(s):  
Hot Spots ◽  
Low Frequency ◽  
Vancomycin Resistance ◽  
Conjugative Transposons ◽  
Target Dna ◽  
Enterococcus Spp ◽  
Clostridium Symbiosum ◽  
Gnotobiotic Mice ◽  
Flanking Regions

ABSTRACT The vancomycin resistance vanB2 gene cluster is disseminated worldwide and has been found in phylogenetically remote bacterial genera. The vanB2 operon is part of conjugative transposons Tn1549/Tn5382, but conjugative transposition of these elements has not been demonstrated. We have obtained transfer of a Tn1549-like element (referred to herein as “Tn1549-like”) from Clostridium symbiosum MLG101 to Enterococcus faecium 64/3 and Enterococcus faecalis JH2-2 in the digestive tract of gnotobiotic mice and to E. faecium 64/3 in vitro. Retransfer of Tn1549-like from an E. faecium transconjugant also containing Tn916 to E. faecium BM77 was obtained in vitro, albeit at a very low frequency. Transfer efficiency was found to be both donor and recipient dependent. Pulsed-field gel electrophoresis analysis of total SmaI-digested DNA of 48 transconjugants indicated in 27 instances the acquisition of ca. 34 kb of DNA. Two transconjugants harbored two copies of the transposon. Sequencing of the flanking regions of Tn1549-like in 48 transconjugants revealed 29 integration events in 26 loci in the E. faecium genome, and two hot spots for insertion were identified. Integration of the transposon was associated with the acquisition of 5 (n = 18) or 6 (n = 7) bp of donor DNA or with 5-bp duplications of target DNA in the remaining transconjugants. These data demonstrate functionality of the Tn1549-like element and attest that the transfer of the vanB operon between enterococci and human commensal anaerobes occurs in the intestinal environment.

scholarly journals Molecular Characterization of IS1541Insertions in the Genome of Yersinia pestis

1998 ◽  
Vol 180 (1) ◽  
pp. 178-181 ◽  
Author(s):  
Monique Odaert ◽  
Annie Devalckenaere ◽  
Patrick Trieu-Cuot ◽  
Michel Simonet
Keyword(s):  
Yersinia Pestis ◽  
Hot Spots ◽  
Insertion Sequence ◽  
Single Copy ◽  
Open Reading Frames ◽  
Stem Loop ◽  
Insertion Sites ◽  
Flanking Regions ◽  
Reading Frames

ABSTRACT The genome of Yersinia pestis, the causative agent of plague, contains at least 30 copies of an element, designated IS1541, which is structurally related to IS200(85% identity). One such element is inserted within the chromosomalinv gene (M. Simonet, B. Riot, N. Fortineau, and P. Berche, Infect. Immun. 64:375–379, 1996). We characterized other IS1541 insertions by cloning 14 different Y. pestis 6/69M loci carrying a single copy of this insertion sequence (IS) into Escherichia coli and, for each element, sequencing 250 bp of both flanking regions. In no case was this IS element inserted into large open reading frames; however, in eight cases, it was detected downstream (17 to 139 bp) of genes thought to be transcribed monocistronically or which constituted the last gene of an operon, and in only one case was it detected upstream (37 bp) of the first gene of an operon. Sequence analysis revealed stem-loop structures (ΔG, <−10 kcal) resembling rho-independent transcription terminators in 8 of the 14 insertion sites. These motifs might constitute hot spots for insertion of this IS1541element within the Y. pestis genome.

scholarly journals A New IS4 Family Insertion Sequence, IS4Bsu1, Responsible for Genetic Instability of Poly-γ-Glutamic Acid Production in Bacillus subtilis

2000 ◽  
Vol 182 (9) ◽  
pp. 2387-2392 ◽  
Author(s):  
Toshiro Nagai ◽  
Lam-Son Phan Tran ◽  
Yasuhiro Inatsu ◽  
Yoshifumi Itoh
Keyword(s):  
Bacillus Subtilis ◽  
Hot Spots ◽  
High Frequency ◽  
Insertion Sequence ◽  
Regulatory System ◽  
Stationary Growth Phase ◽  
Stationary Growth ◽  
Target Sites ◽  
Glutamic Acid Production ◽  
Flanking Regions

ABSTRACT Certain Bacillus subtilis strains, such as B. subtilis (natto) starter strains for the manufacture of natto (fermented soybeans), produce capsular poly-γ-glutamate (γPGA). In B. subtilis (natto), γPGA synthesis is controlled by the ComP-ComA two-component regulatory system and thereby induced at the beginning of the stationary growth phase. We have found a new insertion sequence (IS), designated IS4Bsu1, in the comP gene of a spontaneous γPGA-negative mutant of B. subtilis (natto) NAF4. IS4Bsu1 (1,406 bp), the first IS discovered inB. subtilis, encodes a putative transposase (Tpase) with a predicted M r of 34,895 (374 residues) which displays similarity to the Tpases of IS4 family members. Southern blot analyses have identified 6 to 11 copies of IS4Bsu1, among which 6 copies were at the same loci, in the chromosomes of B. subtilis (natto) strains, including NAF4, three commercial starters, and another three γPGA-producing B. subtilis (natto) strains. All of the eight spontaneous γPGA− mutants, which were derived from five independent NAF4 cultures, had a new additional IS4Bsu1 copy in comP at six different positions within 600 bp of the 5′-terminal region. The target sites of IS4Bsu1 were determined to be AT-rich 9-bp sequences by sequencing the flanking regions of IS4Bsu1 in mutantcomP genes. These results indicate that IS4Bsu1transposes by the replicative mechanism, in contrast to other IS4 members that use the conservative mechanism, and that most, if not all, of spontaneous γPGA− mutants appear to have resulted from the insertion of IS4Bsu1 exclusively into comP. The presence of insertion hot spots incomP, which is essential for γPGA synthesis, as well as high transposition activity, would account for the high frequency of spontaneous γPGA− mutation by IS4Bsu1 inB. subtilis (natto).

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

World Bank pinpoints disaster hot spots

Nature ◽  
2005 ◽  
Author(s):  
Deirdre Lockwood
Keyword(s):  
World Bank ◽  
Hot Spots

Paddy methane hot spots

Nature India ◽  
2008 ◽  
Keyword(s):  
Hot Spots

CSF-concentrations of tau-protein, phospho-tau-protein (181) and amyloid-beta (1–42) in patients with stable and non-stable MCI

2009 ◽  
Vol 42 (05) ◽  
Author(s):  
E Kaiser ◽  
PA Thomann ◽  
U Seidl ◽  
J Schröder
Keyword(s):  
Amyloid Beta ◽  
Tau Protein

Was unterscheidet die Subtypen der Creutzfeldt-Jakob-Krankheit von anderen Demenzen mit initialen psychiatrischen Auffälligkeiten?

2003 ◽  
Vol 01 (01) ◽  
pp. 24-29
Author(s):  
H. Wormstall ◽  
M. Bartels ◽  
G.W. Eschweiler
Keyword(s):  
Tau Protein ◽  
Fur Protein ◽  
T2 Mri ◽  
Codon 129

ZusammenfassungSeit dem Nachweis boviner spongiformer Enzephalopathie (BSE) unter Rindern in Deutschland im November 2000 ist die Gefahr, an der neuen Variante der Creutzfeld-Jakob-Krankheit (vCJD) zu erkranken, auch hierzulande größer geworden. Diese Übersicht schildert die Differenzialdiagnostik von Demenzerkrankungen mit initialen psychiatrischen Auffälligkeiten im jüngeren und höheren Alter. Besonderer Wert wird auf die Unterschiede zwischen der sporadischen Creutzfeld-Jakob-Krankheit (sCJD) und der vCJD gelegt. Neben den klinischen und initial meist psychiatrisch geprägten Verläufen werden neuere laborchemische, molekulargenetische und neuroradiologische Aspekte dieser beiden Prionkrankheiten dargestellt. Der Liquor ist in den meisten Fällen positiv für Protein 14-3-3, Tau-Protein und Neuron-spezifische Enolase (NSE). Nur bei bestimmten molekulargenetisch am Codon 129 des Prionproteins determinierten Subgruppen der sCJD-Patienten, nicht aber bei vCJD-Patienten, finden sich im EEG periodische scharfe Wellen. In der Frühdiagnostik der sCJD kann vor allem die diffusionsgewichtete MRI eingesetzt werden. Bei den jüngeren vCJD-Patienten findet man neben den psychiatrischen Symptomen Parästhesien, erst später eine Demenz und Ataxie von mehr als 6 Monaten Dauer sowie T2-MRI-Signalhyperintensitäten im Pulvinar. Als weitere Differenzialdiagnosen der verschiedenen CJD-Subtypen wird auch die wenig bekannte Hashimoto-Enzephalopathie näher beschrieben.

Cloning of the cDNA Encoding Human Platelet CD36: Comparison to PCR Amplified Fragments of Monocyte, Endothelial and HEL Cells

1993 ◽  
Vol 70 (03) ◽  
pp. 500-505 ◽  
Author(s):  
B Wyler ◽  
L Daviet ◽  
H Bortkiewicz ◽  
J-C Bordet ◽  
J L McGregor
Keyword(s):  
Apparent Molecular Weight ◽  
Platelet Glycoprotein ◽  
Rt Pcr ◽  
Post Translational Modifications ◽  
Hel Cells ◽  
Flanking Region ◽  
Polymerase Chain ◽  
A Minor ◽  
Flanking Regions ◽  
Cdna Fragments

SummaryGlycoprotein CD36, also known as GPIIIb or GPIV, is a major platelet glycoprotein that bears the newly identified Naka alloantigen. The aim of this study was to clone platelet CD36 and investigate other forms of CD36-cDNA present in monocytes, endothelial and HEL cells. RNA from above mentioned cells were reverse transcribed (RT), using specific primers for CD36, and amplified by the polymerase chain reaction (PCR) technique. Sequencing the different amplified platelet derived cDNA fragments, spanning the whole coding and flanking regions, showed the near identity between platelet and CD36-placenta cDNA. Platelet CD36-cDNA cross-hybridized, in Southern blots, with RT-PCR amplified cDNA originating from monocytes, endothelial and HEL cells. However, monocytes showed a RT-PCR amplified cDNA fragment (561 bp) that was present in platelets and placenta but not on endothelial on HEL-cells. Northern blot analysis of platelet RNA hybridized with placenta CD36 indicated the presence of a major (1.95 kb) and a minor (0.95 kb) transcript. The 1.95 kb transcript was the only one observed on Northern blots of monocytes, endothelial and HEL cells. These results indicate that the structure of CD36 expressed in platelets is similar, with the exception of the 3’ flanking region, to that of placenta. Differences in apparent molecular weight between CD36 and CD36-like glycoproteins may be due to post-translational modifications.

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