scholarly journals The Rhizobium GstI Protein Reduces the NH4+ Assimilation Capacity of Rhizobium leguminosarum

2001 ◽  
Vol 14 (7) ◽  
pp. 823-831 ◽  
Author(s):  
Rosarita Tatè ◽  
Luigi Mandrich ◽  
Maria R. Spinosa ◽  
Anna Riccio ◽  
Alessandro Lamberti ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Rhizobium Leguminosarum ◽  
Inducible Promoter ◽  
Complete Loss ◽  
Host Cells ◽  
Single Amino Acid ◽  
Assimilation Capacity ◽  
Translational Inhibitor ◽  
Glutamine Synthetase I ◽  
N Status

We show that the protein encoded by the glutamine synthetase translational inhibitor (gstI) gene reduces the NH4+ assimilation capacity of Rhizobium leguminosarum. In this organism, gstI expression is regulated by the ntr system, including the PII protein, as a function of the nitrogen (N) status of the cells. The GstI protein, when expressed from an inducible promoter, inhibits glutamine synthetase II (glnII) expression under all N conditions tested. The induction of gstI affects the growth of a glutamine synthetase I (glnA-) strain and a single amino acid substitution (W48D) results in the complete loss of GstI function. During symbiosis, gstI is expressed in young differentiating symbiosomes (SBs) but not in differentiated N2-fixing SBs. In young SBs, the PII protein modulates the transcription of NtrC-regulated genes such as gstI and glnII. The evidence presented herein strengthens the idea that the endocytosis of bacteria inside the cytoplasm of the host cells is a key step in the regulation of NH4+ metabolism.

Mutational analysis of GstI protein, a glutamine synthetase translational inhibitor of Rhizobium leguminosarum

FEBS Letters ◽  
2004 ◽  
Vol 558 (1-3) ◽  
pp. 45-51 ◽  
Author(s):  
Chiara Napolitani ◽  
Luigi Mandrich ◽  
Anna Riccio ◽  
Alessandro Lamberti ◽  
Giuseppe Manco ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Rhizobium Leguminosarum ◽  
Mutational Analysis ◽  
Protein A ◽  
Translational Inhibitor

The Rhizobium leguminosarum biovar phaseoli glnT gene, encoding glutamine synthetase III

Gene ◽  
1992 ◽  
Vol 119 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Maurizio Chiurazzi ◽  
Roberto Meza ◽  
Miguel Lara ◽  
Armin Lahm ◽  
Roberto Defez ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Rhizobium Leguminosarum ◽  
Gene Encoding

scholarly journals Regulation of Glutamine Synthetase Isoenzymes in Rhizobium leguminosarum biovar viceae

Microbiology ◽  
1989 ◽  
Vol 135 (3) ◽  
pp. 629-637 ◽  
Author(s):  
M. Rossi ◽  
R. Defez ◽  
M. Chiurazzi ◽  
A. Lamberti ◽  
A. Fuggi ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Rhizobium Leguminosarum

Genetic determinants of glutamine synthetase inDrosophila melanogaster: A gene for glutamine synthetase I resides in the 21B3-6 region

1988 ◽  
Vol 26 (9-10) ◽  
pp. 571-584 ◽  
Author(s):  
Corrado Caggese ◽  
Ruggiero Caizzi ◽  
Maria Pia Bozzetti ◽  
Paolo Barsanti ◽  
Ferruccio Ritossa
Keyword(s):  
Glutamine Synthetase ◽  
Genetic Determinants ◽  
Glutamine Synthetase I

scholarly journals Multiple Xanthomonas euvesicatoria Type III Effectors Inhibit flg22-Triggered Immunity

2016 ◽  
Vol 29 (8) ◽  
pp. 651-660 ◽  
Author(s):  
Georgy Popov ◽  
Malou Fraiture ◽  
Frederic Brunner ◽  
Guido Sessa
Keyword(s):  
Pseudomonas Syringae ◽  
Map Kinases ◽  
Molecular Mechanisms ◽  
Inducible Promoter ◽  
Effector Proteins ◽  
Host Cells ◽  
In Planta ◽  
Callose Deposition ◽  
Type Iii ◽  
Xanthomonas Euvesicatoria

Xanthomonas euvesicatoria is the causal agent of bacterial spot disease in pepper and tomato. X. euvesicatoria bacteria interfere with plant cellular processes by injecting effector proteins into host cells through the type III secretion (T3S) system. About 35 T3S effectors have been identified in X. euvesicatoria 85-10, and a few of them were implicated in suppression of pattern-triggered immunity (PTI). We used an Arabidopsis thaliana pathogen-free protoplast–based assay to identify X. euvesicatoria 85-10 effectors that interfere with PTI signaling induced by the bacterial peptide flg22. Of 33 tested effectors, 17 inhibited activation of a PTI-inducible promoter. Among them, nine effectors also interfered with activation of an abscisic acid–inducible promoter. However, effectors that inhibited flg22-induced signaling did not affect phosphorylation of mitogen-activated protein (MAP) kinases acting downstream of flg22 perception. Further investigation of selected effectors revealed that XopAJ, XopE2, and XopF2 inhibited activation of a PTI-inducible promoter by the bacterial peptide elf18 in Arabidopsis protoplasts and by flg22 in tomato protoplasts. The effectors XopF2, XopE2, XopAP, XopAE, XopH, and XopAJ inhibited flg22-induced callose deposition in planta and enhanced disease symptoms caused by attenuated Pseudomonas syringae bacteria. Finally, selected effectors were found to localize to various plant subcellular compartments. These results indicate that X. euvesicatoria bacteria utilize multiple T3S effectors to suppress flg22-induced signaling acting downstream or in parallel to MAP kinase cascades and suggest they act through different molecular mechanisms.

Mutations in the glutamine synthetase I (gsI) gene produce embryo-lethal female sterility inDrosophila melanogaster

1992 ◽  
Vol 13 (5) ◽  
pp. 359-366 ◽  
Author(s):  
Corrado Caggese ◽  
Ruggiero Caizzi ◽  
Paolo Barsanti ◽  
Maria Pia Bozzetti
Keyword(s):  
Glutamine Synthetase ◽  
Female Sterility ◽  
Glutamine Synthetase I

scholarly journals Combinatorial Mutagenesis and Selection to Understand and Improve Yeast Promoters

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Laila Berg ◽  
Trine Aakvik Strand ◽  
Svein Valla ◽  
Trygve Brautaset
Keyword(s):  
Reporter Gene ◽  
Glucose Repression ◽  
Gene Dosage ◽  
Point Mutations ◽  
Plasmid Vector ◽  
Global Gene Expression ◽  
Inducible Promoter ◽  
Host Cells ◽  
Direct Selection ◽  
Combinatorial Mutagenesis

Microbial promoters are important targets both for understanding the global gene expression and developing genetic tools for heterologous expression of proteins and complex biosynthetic pathways. Previously, we have developed and used combinatorial mutagenesis methods to analyse and improve bacterial expression systems. Here, we present for the first time an analogous strategy for yeast. Our model promoter is the strong and inducible promoter in methylotrophicPichia pastoris. The Zeocin resistance gene was applied as a valuable reporter for mutant promoter activity, and we used an episomal plasmid vector to ensure a constant reporter gene dosage in the yeast host cells. This novel design enabled direct selection for colonies of recombinant cells with altered Zeocin tolerance levels originating solely from randomly introduced point mutations in the promoter DNA sequence. We demonstrate that this approach can be used to select for promoter variants with abolished glucose repression in large mutant libraries. We also selected promoter variants with elevated expression level under induced conditions. The properties of the selected promoter variants were confirmed by expressing luciferase as an alternative reporter gene. The tools developed here should be useful for effective screening, characterization, and improvement of any yeast promoters.

Characterization and Cloning of Two Rhizobium leguminosarum Genes Coding for Glutamine Synthetase Activities

Microbiology ◽  
1986 ◽  
Vol 132 (9) ◽  
pp. 2561-2569
Author(s):  
M. M. K. FILSER ◽  
C. MOSCATELLI ◽  
A. LAMBERTI ◽  
E. VINCZE ◽  
M. GUIDA ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Rhizobium Leguminosarum

scholarly journals The Arg279Glu Substitution in the Adenovirus Type 11p (Ad11p) Fiber Knob Abolishes EDTA-Resistant Binding to A549 and CHO-CD46 Cells, Converting the Phenotype to That of Ad7p

2006 ◽  
Vol 80 (4) ◽  
pp. 1897-1905 ◽  
Author(s):  
Dan J. Gustafsson ◽  
Anna Segerman ◽  
Kristina Lindman ◽  
Ya-Fang Mei ◽  
Göran Wadell
Keyword(s):  
Amino Acid ◽  
Adenovirus Type ◽  
Cell Interaction ◽  
Amino Acid Identity ◽  
Host Cells ◽  
Single Amino Acid ◽  
Receptor Interaction ◽  
Coxsackie Adenovirus Receptor ◽  
Cellular Attachment ◽  
Adenovirus Receptor

ABSTRACT The major determinant of adenovirus (Ad) attachment to host cells is the C-terminal knob domain of the trimeric fiber protein. Ad type 11p (Ad11p; species B2) in contrast to Ad7p (species B1) utilizes at least two different cellular attachment receptors, designated sBAR (species B adenovirus receptor) and sB2AR (species B2 adenovirus receptor). CD46 has recently been identified as one of the Ad11p attachment receptors. However, CD46 did not seem to constitute a functional receptor for Ad7p. Although Ad7p shares high knob amino acid identity with Ad11p, Ad7p is deficient in binding to both sB2AR and CD46. To determine what regions of the Ad11p fiber knob are necessary for sB2AR-CD46 interaction, we constructed recombinant fiber knobs (rFK) with Ad11p/Ad7p chimeras and Ad11p sequences having a single amino acid substitution from Ad7p. Binding of the constructs to A549 and CHO-CD46 BC1 isoform-expressing cells was analyzed by flow cytometry. Our results indicate that an Arg279Glu substitution is sufficient to convert the Ad11p receptor-interaction phenotype to that of Ad7p and abolish sB2AR and CD46 interaction. Also a Glu279Arg substitution in Ad7p rFKs increases CD46 binding. Thus, the lateral HI loop of the Ad11p fiber knob seems to be the key determinant for Ad11p sB2AR-CD46 interaction. This result is comparable to another non-coxsackie-adenovirus receptor binding Ad (Ad37p), where substitution of one amino acid abolishes virus-cell interaction. In conjunction with previous results, our findings also strongly suggest that sB2AR is equivalent to CD46.

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