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21.
Marc Uzan Renée Favre Edith Gallay Lucien Caro 《Molecular & general genetics : MGG》1981,182(3):462-470
Summary Eight ilvC transducing phages generated from E. coli K12 secondary site lysogens have been analysed genetically and physically. Two of them carry, in addition, the rho gene and its promotor region, but not the cya gene. The ilvO603 mutation has been located between ilvG and ilvE. Electrophoretic analysis of the proteins synthesized by these phages in a system of UV irradiated cells allowed us to assign molecular weights of 55000 and 66000 daltons to the ilvC and the ilvD gene products, respectively, and to show that an ilvG-encoded polypeptide of 60000 daltons is made from an ilvO
- but not from an ilvO
+ phage. The expression of the ilvG gene is discussed in the light of the recent finding of a promoter-attenuator region lying upstream to ilvG. Finally, we have found that one of the ilv phages does not have the classical structure of a transducing phage. 相似文献
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Zusammenfassung Der Waldrapp verfügt als soziale Vogelart über Verhaltensweisen des Gruppen- wie Paarkontaktes, die durch Veränderung von Körperumriß und Färbung unbefiederter Hautstellen verstärkt werden können: Grüßen, Imponieren, Aggressivverhalten (auch bei Nestlingen), Beschwichtigen, soziale Körperpflege, Kopula, Nestbau-Verhalten, Paarsitzen. Für das Zusammenspiel der Kolonie wichtig sind Grüßen, verschiedene Formen des Imponierens und ritualisierte Aggressionshandlungen. Das Fortpflanzungsgeschehen synchronisieren soziale Gefiederpflege, Kopulationen (bzw. Scheinkopulae) und Nestbauhandlungen. Das Paarsitzen, besonders deutlich außerhalb der Brutperiode, zeigt vermutlich Monogamie an.Das Lautrepertoire, eintönig für das menschliche Ohr, ist individuell variabel.Eine Besonderheit der Waldrappe ist auch die Nestlings-Aggressivität. Nestgeschwister trachten, einander durch Schnabelhiebe in eine Beschwichtigungshaltung zu drängen und so am Betteln zu hindern. Das Verhalten erlischt bei Erreichen eines Gewichtes von ca. 800 g, zugleich mit dem Abflachen der Wachstumskurve. Da Waldrappe ab dem ersten Ei brüten, überleben untergewichtige Letztgeschlüpfte (Nesthäkchen) bei ausreichendem Nahrungsangebot aufgrund ihrer länger anhaltenden Aggressivität.
Social behaviour of the Bald IbisGeronticus eremita — observations at the Alpenzoo, Innsbruck
Summary As a social bird the Bald Ibis shows behaviour patterns for group contact as well as for pair contact: greeting, display, aggressive behaviour of adults and sibling competition, appeasement behaviour, social preening, nesting behaviour, and Paarsitzen (spatial bond). Some of them may be reinforced by changing body-shape and colour of unfeathered skin. Greeting, some forms of display and ritualized aggressions are important for normal intraspecific interactions. Social preening, copulations (false copulae also) and nesting behaviour do not only stimulate the partner, they also synchronize activity within a colony. Paarsitzen might indicate longer lasting monogamy. The vocal inventory is rather uniform, but some calls may vary individually. — The Bald Ibis shows a strong sibling competition. Siblings force to prevent each other to gape by violent pecking and thus releasing appeasement behaviour. Sibling competition stops with about 800 g at the end of the period of rapid body growth. As the Bald Ibis is breeding with the first egg, this behaviour may allow survival of the runt because of its longer lasting aggressivity when there is sufficient food supply.相似文献
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MH Daleke AD van der Woude AH Parret R Ummels AM de Groot D Watson SR Piersma CR Jiménez J Luirink W Bitter EN Houben 《The Journal of biological chemistry》2012,287(38):31939-31947
Mycobacteria use the dedicated type VII protein secretion systems ESX-1 and ESX-5 to secrete virulence factors across their highly hydrophobic cell envelope. The substrates of these systems include the large mycobacterial PE and PPE protein families, which are named after their characteristic Pro-Glu and Pro-Pro-Glu motifs. Pathogenic mycobacteria secrete large numbers of PE/PPE proteins via the major export pathway, ESX-5. In addition, a few PE/PPE proteins have been shown to be exported by ESX-1. It is not known how ESX-1 and ESX-5 recognize their cognate PE/PPE substrates. In this work, we investigated the function of the cytosolic protein EspG(5), which is essential for ESX-5-mediated secretion in Mycobacterium marinum, but for which the role in secretion is not known. By performing protein co-purifications, we show that EspG(5) interacts with several PPE proteins and a PE/PPE complex that is secreted by ESX-5, but not with the unrelated ESX-5 substrate EsxN or with PE/PPE proteins secreted by ESX-1. Conversely, the ESX-1 paralogue EspG(1) interacted with a PE/PPE couple secreted by ESX-1, but not with PE/PPE substrates of ESX-5. Furthermore, structural analysis of the complex formed by EspG(5) and PE/PPE indicates that these proteins interact in a 1:1:1 ratio. In conclusion, our study shows that EspG(5) and EspG(1) interact specifically with PE/PPE proteins that are secreted via their own ESX systems and suggests that EspG proteins are specific chaperones for the type VII pathway. 相似文献
24.
Zanen G Houben EN Meima R Tjalsma H Jongbloed JD Westers H Oudega B Luirink J van Dijl JM Quax WJ 《The FEBS journal》2005,272(18):4617-4630
Signal peptides that direct protein export in Bacillus subtilis are overall more hydrophobic than signal peptides in Escherichia coli. To study the importance of signal peptide hydrophobicity for protein export in both organisms, the alpha-amylase AmyQ was provided with leucine-rich (high hydrophobicity) or alanine-rich (low hydrophobicity) signal peptides. AmyQ export was most efficiently directed by the authentic signal peptide, both in E. coli and B. subtilis. The leucine-rich signal peptide directed AmyQ export less efficiently in both organisms, as judged from pulse-chase labelling experiments. Remarkably, the alanine-rich signal peptide was functional in protein translocation only in E. coli. Cross-linking of in vitro synthesized ribosome nascent chain complexes (RNCs) to cytoplasmic proteins showed that signal peptide hydrophobicity is a critical determinant for signal peptide binding to the Ffh component of the signal recognition particle (SRP) or to trigger factor, not only in E. coli, but also in B. subtilis. The results show that B. subtilis SRP can discriminate between signal peptides with relatively high hydrophobicities. Interestingly, the B. subtilis protein export machinery seems to be poorly adapted to handle alanine-rich signal peptides with a low hydrophobicity. Thus, signal peptide hydrophobicity appears to be more critical for the efficiency of early stages in protein export in B. subtilis than in E. coli. 相似文献
25.
Simon Schafferer Rimpi Khurana Violetta Refolo Serena Venezia Edith Sturm Paolo Piatti Clara Hechenberger Hubert Hackl Roman Kessler Michaela Willi Ronald Gstir Anne Krogsdam Alexandra Lusser Werner Poewe Gregor K. Wenning Alexander Hüttenhofer Nadia Stefanova 《PloS one》2016,11(3)
Multiple system atrophy (MSA) is a fatal rapidly progressive α-synucleinopathy, characterized by α-synuclein accumulation in oligodendrocytes. It is accepted that the pathological α-synuclein accumulation in the brain of MSA patients plays a leading role in the disease process, but little is known about the events in the early stages of the disease. In this study we aimed to define potential roles of the miRNA-mRNA regulatory network in the early pre-motor stages of the disease, i.e., downstream of α-synuclein accumulation in oligodendroglia, as assessed in a transgenic mouse model of MSA. We investigated the expression patterns of miRNAs and their mRNA targets in substantia nigra (SN) and striatum, two brain regions that undergo neurodegeneration at a later stage in the MSA model, by microarray and RNA-seq analysis, respectively. Analysis was performed at a time point when α-synuclein accumulation was already present in oligodendrocytes at neuropathological examination, but no neuronal loss nor deficits of motor function had yet occurred. Our data provide a first evidence for the leading role of gene dysregulation associated with deficits in immune and inflammatory responses in the very early, non-symptomatic disease stages of MSA. While dysfunctional homeostasis and oxidative stress were prominent in SN in the early stages of MSA, in striatum differential gene expression in the non-symptomatic phase was linked to oligodendroglial dysfunction, disturbed protein handling, lipid metabolism, transmembrane transport and altered cell death control, respectively. A large number of putative miRNA-mRNAs interaction partners were identified in relation to the control of these processes in the MSA model. Our results support the role of early changes in the miRNA-mRNA regulatory network in the pathogenesis of MSA preceding the clinical onset of the disease. The findings thus contribute to understanding the disease process and are likely to pave the way towards identifying disease biomarkers for early diagnosis of MSA. 相似文献
26.
VGJ phi, a novel filamentous phage of Vibrio cholerae, integrates into the same chromosomal site as CTX phi 下载免费PDF全文
Campos J Martínez E Suzarte E Rodríguez BL Marrero K Silva Y Ledón T del Sol R Fando R 《Journal of bacteriology》2003,185(19):5685-5696
We describe a novel filamentous phage, designated VGJ phi, isolated from strain SG25-1 of Vibrio cholerae O139, which infects all O1 (classical and El Tor) and O139 strains tested. The sequence of the 7,542 nucleotides of the phage genome reveals that VGJ phi has a distinctive region of 775 nucleotides and a conserved region with an overall genomic organization similar to that of previously characterized filamentous phages, such as CTX phi of V. cholerae and Ff phages of Escherichia coli. The conserved region carries 10 open reading frames (ORFs) coding for products homologous to previously reported peptides of other filamentous phages, and the distinctive region carries one ORF whose product is not homologous to any known peptide. VGJ phi, like other filamentous phages, uses a type IV pilus to infect V. cholerae; in this case, the pilus is the mannose-sensitive hemagglutinin. VGJ phi-infected V. cholerae overexpresses the product of one ORF of the phage (ORF112), which is similar to single-stranded DNA binding proteins of other filamentous phages. Once inside a cell, VGJ phi is able to integrate its genome into the same chromosomal attB site as CTX phi, entering into a lysogenic state. Additionally, we found an attP structure in VGJ phi, which is also conserved in several lysogenic filamentous phages from different bacterial hosts. Finally, since different filamentous phages seem to integrate into the bacterial dif locus by a general mechanism, we propose a model in which repeated integration events with different phages might have contributed to the evolution of the CTX chromosomal region in V. cholerae El Tor. 相似文献
27.
Stacia R Engel Edith D Wong Robert S Nash Suzi Aleksander Micheal Alexander Eric Douglass Kalpana Karra Stuart R Miyasato Matt Simison Marek S Skrzypek Shuai Weng J Michael Cherry 《Genetics》2022,220(4)
Saccharomyces cerevisiae is used to provide fundamental understanding of eukaryotic genetics, gene product function, and cellular biological processes. Saccharomyces Genome Database (SGD) has been supporting the yeast research community since 1993, serving as its de facto hub. Over the years, SGD has maintained the genetic nomenclature, chromosome maps, and functional annotation, and developed various tools and methods for analysis and curation of a variety of emerging data types. More recently, SGD and six other model organism focused knowledgebases have come together to create the Alliance of Genome Resources to develop sustainable genome information resources that promote and support the use of various model organisms to understand the genetic and genomic bases of human biology and disease. Here we describe recent activities at SGD, including the latest reference genome annotation update, the development of a curation system for mutant alleles, and new pages addressing homology across model organisms as well as the use of yeast to study human disease. 相似文献
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