2,177 research outputs found
Functional analysis of the Bacillus subtilis yshD gene, a mutS paralogue
No full textIn the course of the Bacillus subtilis genome sequencing project, an ORF called yshD was identified, and its product was classified as a mismatch repair protein. Further analysis of the YshD primary sequence showed that the protein belongs to the MutS2 protein family, sharing a high degree of identity with the Thermootoga Inaritima protein TM1278 (34%) and with the so-called MutS2 protein sl11772 of Synechocystis (32%). The COG1193 family of MutS-like proteins is made up of polypeptides that have been predicted from genomic sequencing data from various prokaryotes, but their biological role has not yet been analysed. The functional study of yshD revealed that the gene is constitutively transcribed during the life cycle of B. subtilis, and in minimal medium expression remains at appreciable levels until very late in stationary phase. Fluctuation tests with yshD knock-out mutants did not indicate any role for the protein in preventing the accumulation of spontaneous forward mutations to RifR, nor was any functional interaction with MutS or MutL suggested in fluctuation experiments with mutants lacking combinations of the three genes. Nevertheless, the mutation spectrum observed in the rpoB gene in the deltayshD strain has some characteristic features. The gene does not seem to be involved in the prevention of interspecific recombination in transformation-competent cells
Improvement of Catalytic Properties of Escherichia coli Penicillin G Acylase Immobilized on Glyoxyl Agarose by Addition of a Six-Amino-Acid Tag.
No full textA tag of three lysines alternating with three glycines was added to the C-terminal end of the beta chain of penicillin G acylase (PGA). This modification improved the immobilization efficiency of PGA on glyoxyl agarose and the catalytic properties of the PGA derivative, although it impaired the posttranslational steps of overexpressed protein maturation
Filologia editoriale, Roberto Calasso in dialogo con Paola Italia e Francisco Rico
No full textPaola Italia e Francisco Rico intervengono sul libro di Roberto Calasso, presidente e fondatore di Adelphi Edizioni, L'impronta dell'editore, e discutono di problemi di filologia delle forme editoriali, dal punto di vista dell'autore, del lettore e dell'editore.Paola Italia and Francisco Ricos interview Roberto Calasso, Publisher, Writer, and Founder of Adelphi Edizioni, about his book: L'impronta dell'editore, talking about philology, publishing and editing, from the author, the reader and the publisher's point of view
Paola Gianturco: Women Who Light the Dark
No full textPaola Gianturco is a photographer, author, and advocate for women\u27s rights world-wide. For the past thirteen years, she has worked as a photojournalist, documenting women’s lives in forty countries. She has published four acclaimed photo books which bring together inspiring stories with gorgeous photographs to motivate her readers to engage with, learn from and support women around the world. All of Gianturco’s books are philanthropic projects, for which she donates her royalties to carefully selected nonprofit organizations that relate to each book\u27s content. Paola\u27s most recent book, Women Who Light the Dark, tells the story of local women around the world who are helping one another tackle the problems that darken their lives—including violence, poverty, illiteracy and disease. Gianturco is giving 100% of her author royalties for this book to The Global Fund for Women.https://thekeep.eiu.edu/humanitiescenter_meaningfulwork1011/1002/thumbnail.jp
YrxA is the transcriptional regulator that represses de novo NAD biosynthesis in Bacillus subtilis
No full textThe first genetic, in vivo, and in vitro evidences that YrxA is the regulator of NAD de novo biosynthesis in Bacillus subtilis are hereby reported. The protein is essential to the transcription repression of the divergent operons nadBCA and nifS-yrxA in the presence of nicotinic acid and binds to their shared operator-promoter region
Fusion complexes and CD4-independene Env for the induction of broad spectrum neutralizing antibodies against HIV-1
No full textBroad spectrum neutralizing antibodies against HIV-1 are essential for the development of a humoral anti-AIDS vaccine. We used fusion complexes and CD4-independent gp120 as new immunogens to induce neutralizing antibodies blocking the infectivity of different primary isolates of HIV-1
«Yo soy de Destierrolandia»: Fernando Arrabal y el límite
No full textFernando Arrabal is a Spanish author - actually, no, he isn't. He is a francophone writer, or, more accurately, a Spanish expatriate. Or, on the contrary, he is a traitor, an «afrancesado». In this paper Fernando Arrabal's case will be used as an example of the difficulties that an author has to face when he leaves his own country and moves to another different from a spatial, cultural, and linguistic point of view. Besides, I will analyze the unusual position of the critic in the reception and interpretation of a corpus that, while being obviously connected to its author, cannot refer to a precise national context
HLA-C increases HIV-1 infectivity and is associated with gp120
No full textAbstract Background A recently identified genetic polymorphism located in the 5' region of the HLA-C gene is associated with individual variations in HIV-1 viral load and with differences in HLA-C expression levels. HLA-C has the potential to restrict HIV-1 by presenting epitopes to cytotoxic T cells but it is also a potent inhibitor of NK cells. In addition, HLA-C molecules incorporated within the HIV-1 envelope have been shown to bind to the envelope glycoprotein gp120 and enhance viral infectivity. We investigated this last property in cell fusion assays where the expression of HLA-C was silenced by small interfering RNA sequences. Syncytia formation was analyzed by co-cultivating cell lines expressing HIV-1 gp120/gp41 from different laboratory and primary isolates with target cells expressing different HIV-1 co-receptors. Virus infectivity was analyzed using pseudoviruses. Molecular complexes generated during cell fusion (fusion complexes) were purified and analyzed for their HLA-C content. Results HLA-C positive cells co-expressing HIV-1 gp120/gp41 fused more rapidly and produced larger syncytia than HLA-C negative cells. Transient transfection of gp120/gp41 from different primary isolates in HLA-C positive cells resulted in a significant cell fusion increase. Fusion efficiency was reduced in HLA-C silenced cells compared to non-silenced cells when co-cultivated with different target cell lines expressing HIV-1 co-receptors. Similarly, pseudoviruses produced from HLA-C silenced cells were significantly less infectious. HLA-C was co-purified with gp120 from cells before and after fusion and was associated with the fusion complex. Conclusion Virionic HLA-C molecules associate to Env and increase the infectivity of both R5 and X4 viruses. Genetic polymorphisms associated to variations in HLA-C expression levels may therefore influence the individual viral set point not only by means of a regulation of the virus-specific immune response but also via a direct effect on the virus replicative capacity. These findings have implications for the understanding of the HIV-1 entry mechanism and of the role of Env conformational modifications induced by virion-associated host proteins.</p
Broad spectrum neutralizing monoclonal antibodies against HIV-1 elicited by immunizing with fusion complexes
No full textabstract 14
HLA-C increase fusion efficiency between the HIV-1 envelope and the cell membrane and is part of the fusion complex
No full textThe HIV-1 viral envelope originates from the cell membrane and contains different cellular proteins such as MHC class I molecules, which play a role in modulating viral infectivity. HLA-C is known to enhance viral infectiv- ity and reduce sensitivity to neutralizing antibodies by inducing gp120/41 conformational changes that may increase fusion efficiency and viral infectivity [1]. In this work we studied the effect of HLA-C on syncytia forma- tion and of its association with the HIV-1 gp120/41 and with the CD4/CCR5 receptors in purified fusion com- plexes
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