70 research outputs found

    Adding to Yersinia enterocolitica Gene Pool Diversity: Two Cryptic Plasmids from a Biotype 1A Isolate

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    We report the nucleotide sequence of two novel cryptic plasmids (4357 and 14 662 base pairs) carried by a Yersinia enterocolitica biotype 1A strain isolated from pork. As distinguished from most biotype 1A strains, this isolate, designated 07-04449, exhibited adherence to eukaryotic cells. The smaller plasmid pYe4449-1 carries five attributable open reading frames (ORFs) encoding the first CcdA/CcdB-like antitoxin/toxin system described for a Yersinia plasmid, a RepA-like replication initiation protein, and mobilizing factors MobA and MobC. The deduced amino acid sequences showed highest similarity to proteins described in Salmonella (CcdA/B), Klebsiella (RepA), and Plesiomonas (MobA/C) indicating genomic fluidity among members of the Enterobacteriaceae. One additional ORF with unknown function, termed ORF5, was identified with an ancestry distinct from the rest of the plasmid. While the C+G content of ORF5 is 38.3%, the rest of pYe4449-1 shows a C+G content of 55.7%. The C+G content of the larger plasmid pYe4449-2 (54.9%) was similar to that of pYe4449-1 (53.7%) and differed from that of the Y. enterocolitica genome (47.3%). Of the 14 ORFs identified on pYe4449-2, only six ORFs showed significant similarity to database entries. For three of these ORFs likely functions could be ascribed: a TnpR-like resolvase and a phage replication protein, localized each on a low C+G island, and DNA primase TraC. Two ORFs of pYe4449-2, ORF3 and ORF7, seem to encode secretable proteins. Epitope-tagging of ORF3 revealed protein expression at 4°C but not at or above 27°C suggesting adaptation to a habitat outside swine. The hypothetical protein encoded by ORF7 is the member of a novel repeat protein family sharing the DxxGN(x)nDxxGN motif. Our findings illustrate the exceptional gene pool diversity within the species Y. enterocolitica driven by horizontal gene transfer events

    Analysis of Jmjd6 Cellular Localization and Testing for Its Involvement in Histone Demethylation

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    BACKGROUND: Methylation of residues in histone tails is part of a network that regulates gene expression. JmjC domain containing proteins catalyze the oxidative removal of methyl groups on histone lysine residues. Here, we report studies to test the involvement of Jumonji domain-containing protein 6 (Jmjd6) in histone lysine demethylation. Jmjd6 has recently been shown to hydroxylate RNA splicing factors and is known to be essential for the differentiation of multiple tissues and cells during embryogenesis. However, there have been conflicting reports as to whether Jmjd6 is a histone-modifying enzyme. METHODOLOGY/PRINCIPAL FINDINGS: Immunolocalization studies reveal that Jmjd6 is distributed throughout the nucleoplasm outside of regions containing heterochromatic DNA, with occasional localization in nucleoli. During mitosis, Jmjd6 is excluded from the nucleus and reappears in the telophase of the cell cycle. Western blot analyses confirmed that Jmjd6 forms homo-multimers of different molecular weights in the nucleus and cytoplasm. A comparison of mono-, di-, and tri-methylation states of H3K4, H3K9, H3K27, H3K36, and H4K20 histone residues in wildtype and Jmjd6-knockout cells indicate that Jmjd6 is not involved in the demethylation of these histone lysine residues. This is further supported by overexpression of enzymatically active and inactive forms of Jmjd6 and subsequent analysis of histone methylation patterns by immunocytochemistry and western blot analysis. Finally, treatment of cells with RNase A and DNase I indicate that Jmjd6 may preferentially associate with RNA/RNA complexes and less likely with chromatin. CONCLUSIONS/SIGNIFICANCE: Taken together, our results provide further evidence that Jmjd6 is unlikely to be involved in histone lysine demethylation. We confirmed that Jmjd6 forms multimers and showed that nuclear localization of the protein involves association with a nucleic acid matrix

    C‐reactive protein flare‐response predicts long‐term efficacy to first‐line anti‐PD‐1‐based combination therapy in metastatic renal cell carcinoma

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    Objectives Immune checkpoint blockade (IO) has revolutionised the treatment of metastatic renal cell carcinoma (mRCC). Early C-reactive protein (CRP) kinetics, especially the recently introduced CRP flare-response phenomenon, has shown promising results to predict IO efficacy in mRCC, but has only been studied in second line or later. Here, we aimed to validate the predictive value of early CRP kinetics for 1st-line treatment of mRCC with αPD-1 plus either αCTLA-4 (IO+IO) or tyrosine kinase inhibitor (IO+TKI). Methods In this multicentre retrospective study, we investigated the predictive potential of early CRP kinetics during 1st-line IO therapy. Ninety-five patients with mRCC from six tertiary referral centres with either IO+IO (N = 59) or IO+TKI (N = 36) were included. Patients were classified as CRP flare-responders, CRP responders or non-CRP responders as previously described, and their oncological outcome was compared. Results Our data validate the predictive potential of early CRP kinetics in 1st-line immunotherapy in mRCC. CRP responders, especially CRP flare-responders, had significantly prolonged progression-free survival (PFS) compared with non-CRP responders (median PFS: CRP flare-responder: 19.2 months vs. responders: 16.2 vs. non-CRP responders: 5.6, P < 0.001). In both the IO+IO and IO+TKI subgroups, early CRP kinetics remained significantly associated with improved PFS. CRP flare-response was also associated with long-term response ≄ 12 months. Conclusions Early CRP kinetics appears to be a low-cost and easy-to-implement on-treatment biomarker to predict response to 1st-line IO combination therapy. It has potential to optimise therapy monitoring and might represent a new standard of care biomarker for immunotherapy in mRCC

    A genetically encoded photoactivatable Rac controls the motility of living cells

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    The precise spatio-temporal dynamics of protein activity are often critical in determining cell behaviour, yet for most proteins they remain poorly understood; it remains difficult to manipulate protein activity at precise times and places within living cells. Protein activity has been controlled by light, through protein derivatization with photocleavable moieties1 or using photoreactive small molecule ligands2. However, this requires use of toxic UV wavelengths, activation is irreversible, and/or cell loading is accomplished via disruption of the cell membrane (i.e. through microinjection). We have developed a new approach to produce genetically-encoded photo-activatable derivatives of Rac1, a key GTPase regulating actin cytoskeletal dynamics3,4. Rac1 mutants were fused to the photoreactive LOV (light oxygen voltage) domain from phototropin5,6, sterically blocking Rac1 interactions until irradiation unwound a helix linking LOV to Rac1. Photoactivatable Rac1 (PA-Rac1) could be reversibly and repeatedly activated using 458 or 473 nm light to generate precisely localized cell protrusions and ruffling. Localized Rac activation or inactivation was sufficient to produce cell motility and control the direction of cell movement. Myosin was involved in Rac control of directionality but not in Rac-induced protrusion, while PAK was required for Rac-induced protrusion. PA-Rac1 was used to elucidate Rac regulation of RhoA in cell motility. Rac and Rho coordinate cytoskeletal behaviours with seconds and submicron precision7,8. Their mutual regulation remains controversial9, with data indicating that Rac inhibits and/or activates Rho10,11. Rac was shown to inhibit RhoA in living cells, with inhibition modulated at protrusions and ruffles. A PA-Rac crystal structure and modelling revealed LOV-Rac interactions that will facilitate extension of this photoactivation approach to other proteins

    The differentiation status of primary gonadal germ cell tumors correlates inversely with telomerase activity and the expression level of the gene encoding the catalytic subunit of telomerase

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    BACKGROUND: The activity of the ribonucleoprotein enzyme telomerase is detectable in germ, stem and tumor cells. One major component of telomerase is human telomerase reverse transcriptase (hTERT), which encodes the catalytic subunit of telomerase. Here we investigate the correlation of telomerase activity and hTERT gene expression and the differentiation status of primary testicular germ cell tumors (TGCT). METHODS: Telomerase activity (TA) was detected by a quantitative telomerase PCR ELISA, and hTERT mRNA expression was quantified by online RT-PCR in 42 primary testicular germ cell tumors. The control group consisted of benign testicular biopsies from infertile patients. RESULTS: High levels of telomerase activity and hTERT expression were detected in all examined undifferentiated TGCTs and in the benign testicular tissue specimens with germ cell content. In contrast, differentiated teratomas and testicular control tissue without germ cells (Sertoli-cell-only syndrome) showed no telomerase activity and only minimal hTERT expression. CONCLUSIONS: These findings demonstrate an inverse relationship between the level of telomerase activity and hTERT mRNA expression and the differentiation state of germ cell tumors. Quantification of telomerase activity and hTERT mRNA expression enables a new molecular-diagnostic subclassification of germ cell tumors that describes their proliferation potential and differentiation status

    Opportunities, barriers, and recommendations in down syndrome research

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    Recent advances in medical care have increased life expectancy and improved the quality of life for people with Down syndrome (DS). These advances are the result of both pre-clinical and clinical research but much about DS is still poorly understood. In 2020, the NIH announced their plan to update their DS research plan and requested input from the scientific and advocacy community. The National Down Syndrome Society (NDSS) and the LuMind IDSC Foundation worked together with scientific and medical experts to develop recommendations for the NIH research plan. NDSS and LuMind IDSC assembled over 50 experts across multiple disciplines and organized them in eleven working groups focused on specific issues for people with DS. This review article summarizes the research gaps and recommendations that have the potential to improve the health and quality of life for people with DS within the next decade. This review highlights many of the scientific gaps that exist in DS research. Based on these gaps, a multidisciplinary group of DS experts has made recommendations to advance DS research. This paper may also aid policymakers and the DS community to build a comprehensive national DS research strategy

    Feilke revisited : 60 Stellenbesuche

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    Weitere Hrsg.: Thorsten Pohl, Sara Rezat, Torsten Steinhoff, Martin SteinseiferAnlĂ€sslich des 60. Geburtstags des Linguisten und Sprachdidaktikers Helmuth Feilke wurden Wegbegleiterinnen und Wegbegleiter gebeten, einzelne Stellen in seinen wissenschaftlichen Schriften erneut zu besuchen. Entstanden sind pointierte Kommentare, kurze wissenschaftliche Abhandlungen und Analysen, Varianten auch des kritischen und kontroversen Nach- und Weiterdenkens und AnsĂ€tze zur Neu- oder Re-Kontextualisierung. Je nach wissenschaftlicher Vita der Autorinnen und Autoren kann es sich um Stellen handeln, deren Rezeption zeitlich weit zurĂŒckliegt, oder um Passagen, die ganz aktuelle Fragen der eigenen Forschungsarbeit tangieren. Abgesehen davon, dass ein kurzes Format fĂŒr die BeitrĂ€ge gewĂ€hlt und die Autorinnen und Autoren gebeten wurden, die ausgewĂ€hlte Stelle knapp zu verorten und zu erlĂ€utern, war die Bearbeitungsform gĂ€nzlich freigestellt. So sind Texte in einer Bandbreite von pointierten Kommentaren, kurzen wissenschaftlichen Abhandlungen und Analysen, Varianten des Nach- und Weiterdenkens, AnsĂ€tze zur Neu- oder Re-Kontextualisierung bis hin zu Formen des kritischen Hinterfragens und der kontroversen Auseinandersetzung entstanden

    Das finnische Bildungssystem - Wege zum Erfolg

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    Angelika HahnKlagenfurt, Alpen-Adria-Univ., Dipl.-Arb., 2015(VLID)241199

    Entwicklung des Gesamtparks der Villa Berg, Strukturen und Verflechtungen

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    keine vorhanden

    Annotated checklist and biodiversity analysis of benthic fauna at Sylt Outer Reef and Borkum Reef Ground (North Sea)

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    Benthic fauna caught by ring dredge and 2 m beam trawl at the NATURA 2000 Sylt Outer Reef (SAR) and Borkum Reef Ground (BRG) sites in the North Sea are examined in relation to the intensity of mobile bottom-trawling fisheries. Samples were taken from 33 stations in the two areas, and the collected benthic fauna, consisting of infauna, epifauna, and demersal fish was determined. A total of 123 species were found, consisting of the phyla Chordata, Mollusca, Arthropoda, Echinodermata, Annelida, Cnidaria, and Bryozoa, with Chordata and Mollusca being the most species-rich phyla. The species compositions of BRG and SAR are relatively clearly separated. There was greater species diversity at BRG, likely due to lower fishing pressure from mobile bottom trawling than at SAR. Long-term data acquisition and analysis will be needed to visualize past and future changes in biodiversit
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