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941.
Tania Lucia Montenegro Stamford Thayza Christina Montenegro Stamford Newton Pereira Stamford Carolina Etienne Rosália Silva Santos Maria do Carmo Catanho Pereira de Lyra Yong Ha-Park Jin-Won Bae Janete Magali Araújo 《World journal of microbiology & biotechnology》2007,23(12):1719-1724
An endophytic actinomycete isolated from tubers of yam beam (Pachyrhizus erosus L. Urban) was classified as a novel species nominated Kitasatospora recifensis based in phenotypic and genotypic analysis (16S rDNA gene sequence). Monosporic culture using specific ISP2 media revealed
three interspecies, which were identified by DNA southern hybridization (Wild strain 13817 W, Aerial Mycelium strain 13817
AM and Vegetative Mycelium strain 13817 VM). The strains were tested for the production of amylolitic enzymes in alternative
media. Maximum yields for both enzymes were observed in starch-casein. Higher α-amylase was obtained with strain 13817 W in
starch-urea, and amyloglucosidase with strain 13817 AM in starch-ammonium that are economic sources and may be important for
industrial purposes. Type strain (DAUFPE 13817
T
= KCTC 9972T = DSM 44943T). 相似文献
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943.
This study was designed to analyse the time-of-day effect in maximal anaerobic power, and the influence of menstrual cycle phase and oral contraceptive use on any diurnal effect. Diurnal variations in maximal cycling power were studied in 11 eumenorrheic women and 10 women using monophasic oral contraceptives. Subjects were tested at 09:00, 14:00 and 18:00 hours, assigned randomly on separate days, in the mid-follicular or pseudo-follicular phase (days 7, 8, 9) and in the mid-luteal or pseudo-luteal phase (days 19, 20, 21) of the menstrual cycle. The order of test sessions was randomly assigned. Body mass was measured before, and rectal temperature after, a standardized 15-min warm-up. Maximal cycling power (Pc) was determined by a force-velocity test. Rectal temperature significantly increased from morning (09:00) to afternoon (14:00 and 18:00) in follicular and luteal phases for eumenorrheic subjects, and in days 7–9 and days 19–21 for contraceptive users (p < 0.05). No significant interaction effects (time of day × group × cycle phase) were observed for rectal temperature. In eumenorrheic subjects, Pc increased significantly from 09:00 to afternoon during the follicular phase (P < 0.05). In contrast, no significant time-of-day effects were observed during the luteal phase in eumenorrheic subjects, and at any cycle phase in contraceptive users. Analysis of variance failed to reveal any significant interaction effects for Pc. This study suggested that the time-of-day effect on maximal anaerobic power could be damped during the luteal phase of eumenorrheic women or at any cycle phase by oral contraceptive use. 相似文献
944.
Emmanuel Martin Sophie Theis Guillaume Gay Bruno Monier Christian Rouvière Magali Suzanne 《Developmental cell》2021,56(5):687-701.e7
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945.
Magali Trayssac Christopher J. Clarke Jeffrey L. Stith Justin M. Snider Naomi Newen Christopher R. Gault Yusuf A. Hannun Lina M. Obeid 《Cell death & disease》2021,12(1)
Senescence is an antiproliferative mechanism that can suppress tumor development and can be induced by oncogenes such as genes of the Ras family. Although studies have implicated bioactive sphingolipids (SL) in senescence, the specific mechanisms remain unclear. Here, using MCF10A mammary epithelial cells, we demonstrate that oncogenic K-Ras (Kirsten rat sarcoma viral oncogene homolog) is sufficient to induce cell transformation as well as cell senescence—as revealed by increases in the percentage of cells in the G1 phase of the cell cycle, p21WAF1/Cip1/CDKN1A (p21) expression, and senescence-associated β-galactosidase activity (SA-β-gal). Furthermore, oncogenic K-Ras altered SL metabolism, with an increase of long-chain (LC) C18, C20 ceramides (Cer), and very-long-chain (VLC) C22:1, C24 Cer, and an increase of sphingosine kinase 1 (SK1) expression. Since Cer and sphingosine-1-phosphate have been shown to exert opposite effects on cellular senescence, we hypothesized that targeting SK1 could enhance oncogenic K-Ras-induced senescence. Indeed, SK1 downregulation or inhibition enhanced p21 expression and SA-β-gal in cells expressing oncogenic K-Ras and impeded cell growth. Moreover, SK1 knockdown further increased LC and VLC Cer species (C18, C20, C22:1, C24, C24:1, C26:1), especially the ones increased by oncogenic K-Ras. Fumonisin B1 (FB1), an inhibitor of ceramide synthases (CerS), reduced p21 expression induced by oncogenic K-Ras both with and without SK1 knockdown. Functionally, FB1 reversed the growth defect induced by oncogenic K-Ras, confirming the importance of Cer generation in the senescent phenotype. More specifically, downregulation of CerS2 by siRNA blocked the increase of VLC Cer (C24, C24:1, and C26:1) induced by SK1 knockdown and phenocopied the effects of FB1 on p21 expression. Taken together, these data show that targeting SK1 is a potential therapeutic strategy in cancer, enhancing oncogene-induced senescence through an increase of VLC Cer downstream of CerS2.Subject terms: Cancer metabolism, Senescence 相似文献
946.
Cinzia Cameli Marta Viggiano Magali J. Rochat Alessandra Maresca Leonardo Caporali Claudio Fiorini Flavia Palombo Pamela Magini Renée C. Duardo Fabiola Ceroni Maria C. Scaduto Annio Posar Marco Seri Valerio Carelli Paola Visconti Elena Bacchelli Elena Maestrini 《Journal of cellular and molecular medicine》2021,25(5):2459-2470
Autism spectrum disorder (ASD) is characterized by a complex polygenic background, but with the unique feature of a subset of cases (~15%-30%) presenting a rare large-effect variant. However, clinical interpretation in these cases is often complicated by incomplete penetrance, variable expressivity and different neurodevelopmental trajectories. NRXN1 intragenic deletions represent the prototype of such ASD-associated susceptibility variants. From chromosomal microarrays analysis of 104 ASD individuals, we identified an inherited NRXN1 deletion in a trio family. We carried out whole-exome sequencing and deep sequencing of mitochondrial DNA (mtDNA) in this family, to evaluate the burden of rare variants which may contribute to the phenotypic outcome in NRXN1 deletion carriers. We identified an increased burden of exonic rare variants in the ASD child compared to the unaffected NRXN1 deletion-transmitting mother, which remains significant if we restrict the analysis to potentially deleterious rare variants only (P = 6.07 × 10−5). We also detected significant interaction enrichment among genes with damaging variants in the proband, suggesting that additional rare variants in interacting genes collectively contribute to cross the liability threshold for ASD. Finally, the proband's mtDNA presented five low-level heteroplasmic mtDNA variants that were absent in the mother, and two maternally inherited variants with increased heteroplasmic load. This study underlines the importance of a comprehensive assessment of the genomic background in carriers of large-effect variants, as penetrance modulation by additional interacting rare variants to might represent a widespread mechanism in neurodevelopmental disorders. 相似文献
947.
Herrera-González Azucena Núñez-López Gema Morel Sandrine Amaya-Delgado Lorena Sandoval Georgina Gschaedler Anne Remaud-Simeon Magali Arrizon Javier 《Applied microbiology and biotechnology》2017,101(13):5223-5234
Applied Microbiology and Biotechnology - Enzymatic fructosylation of organic acceptors other than sugar opens access to the production of new molecules that do not exist in nature. These new... 相似文献
948.
Liza Felicori Katie H. Jameson Pierre Roblin Mark J. Fogg Transito Garcia-Garcia Magali Ventroux Micka?l V. Cherrier Alexandre Bazin Philippe Noirot Anthony J. Wilkinson Franck Molina Laurent Terradot Marie-Fran?oise Noirot-Gros 《Nucleic acids research》2016,44(1):449-463
YabA negatively regulates initiation of DNA replication in low-GC Gram-positive bacteria. The protein exerts its control through interactions with the initiator protein DnaA and the sliding clamp DnaN. Here, we combined X-ray crystallography, X-ray scattering (SAXS), modeling and biophysical approaches, with in vivo experimental data to gain insight into YabA function. The crystal structure of the N-terminal domain (NTD) of YabA solved at 2.7 Å resolution reveals an extended α-helix that contributes to an intermolecular four-helix bundle. Homology modeling and biochemical analysis indicates that the C-terminal domain (CTD) of YabA is a small Zn-binding domain. Multi-angle light scattering and SAXS demonstrate that YabA is a tetramer in which the CTDs are independent and connected to the N-terminal four-helix bundle via flexible linkers. While YabA can simultaneously interact with both DnaA and DnaN, we found that an isolated CTD can bind to either DnaA or DnaN, individually. Site-directed mutagenesis and yeast-two hybrid assays identified DnaA and DnaN binding sites on the YabA CTD that partially overlap and point to a mutually exclusive mode of interaction. Our study defines YabA as a novel structural hub and explains how the protein tetramer uses independent CTDs to bind multiple partners to orchestrate replication initiation in the bacterial cell. 相似文献
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950.