Identification of Francisella tularensis genes encoding exported membrane-associated proteins using TnphoA mutagenesis of a genomic library

2004 ◽  
Vol 37 (4) ◽  
pp. 205-213 ◽  
Author(s):  
Robert D. Gilmore ◽  
Rendi Murphree Bacon ◽  
Steven L. Sviat ◽  
Jeannine M. Petersen ◽  
Scott W. Bearden
Keyword(s):  
Francisella Tularensis ◽  
Genomic Library ◽  
Genes Encoding ◽  
Associated Proteins

scholarly journals Characterization of a Spontaneous Nonmagnetic Mutant of Magnetospirillum gryphiswaldense Reveals a Large Deletion Comprising a Putative Magnetosome Island

2003 ◽  
Vol 185 (19) ◽  
pp. 5779-5790 ◽  
Author(s):  
Sabrina Schübbe ◽  
Michael Kube ◽  
André Scheffel ◽  
Cathrin Wawer ◽  
Udo Heyen ◽  
...  
Keyword(s):  
Genomic Library ◽  
Membrane Vesicles ◽  
Gene Families ◽  
Artificial Chromosome ◽  
Magnetotactic Bacteria ◽  
Growth Conditions ◽  
Large Deletion ◽  
Magnetospirillum Gryphiswaldense ◽  
Genes Encoding ◽  
Associated Proteins

ABSTRACT Frequent spontaneous loss of the magnetic phenotype was observed in stationary-phase cultures of the magnetotactic bacterium Magnetospirillum gryphiswaldense MSR-1. A nonmagnetic mutant, designated strain MSR-1B, was isolated and characterized. The mutant lacked any structures resembling magnetosome crystals as well as internal membrane vesicles. The growth of strain MSR-1B was impaired under all growth conditions tested, and the uptake and accumulation of iron were drastically reduced under iron-replete conditions. A large chromosomal deletion of approximately 80 kb was identified in strain MSR-1B, which comprised both the entire mamAB and mamDC clusters as well as further putative operons encoding a number of magnetosome-associated proteins. A bacterial artificial chromosome clone partially covering the deleted region was isolated from the genomic library of wild-type M. gryphiswaldense. Sequence analysis of this fragment revealed that all previously identified mam genes were closely linked with genes encoding other magnetosome-associated proteins within less than 35 kb. In addition, this region was remarkably rich in insertion elements and harbored a considerable number of unknown gene families which appeared to be specific for magnetotactic bacteria. Overall, these findings suggest the existence of a putative large magnetosome island in M. gryphiswaldense and other magnetotactic bacteria.

scholarly journals Pathogenic Determinants of the Mycobacterium kansasii Complex: An Unsuspected Role for Distributive Conjugal Transfer

2021 ◽  
Vol 9 (2) ◽  
pp. 348
Author(s):  
Florian Tagini ◽  
Trestan Pillonel ◽  
Claire Bertelli ◽  
Katia Jaton ◽  
Gilbert Greub
Keyword(s):  
Genomic Analysis ◽  
Comparative Genomic ◽  
Mycobacterium Kansasii ◽  
Type Vii Secretion ◽  
A Genome ◽  
Genes Encoding ◽  
Associated Proteins ◽  
Immunosuppressed Patients ◽  
Type Vii Secretion System ◽  
Clinical Records

The Mycobacterium kansasii species comprises six subtypes that were recently classified into six closely related species; Mycobacterium kansasii (formerly M. kansasii subtype 1), Mycobacterium persicum (subtype 2), Mycobacterium pseudokansasii (subtype 3), Mycobacterium ostraviense (subtype 4), Mycobacterium innocens (subtype 5) and Mycobacterium attenuatum (subtype 6). Together with Mycobacterium gastri, they form the M. kansasii complex. M. kansasii is the most frequent and most pathogenic species of the complex. M. persicum is classically associated with diseases in immunosuppressed patients, and the other species are mostly colonizers, and are only very rarely reported in ill patients. Comparative genomics was used to assess the genetic determinants leading to the pathogenicity of members of the M. kansasii complex. The genomes of 51 isolates collected from patients with and without disease were sequenced and compared with 24 publicly available genomes. The pathogenicity of each isolate was determined based on the clinical records or public metadata. A comparative genomic analysis showed that all M. persicum, M. ostraviense, M innocens and M. gastri isolates lacked the ESX-1-associated EspACD locus that is thought to play a crucial role in the pathogenicity of M. tuberculosis and other non-tuberculous mycobacteria. Furthermore, M. kansasii was the only species exhibiting a 25-Kb-large genomic island encoding for 17 type-VII secretion system-associated proteins. Finally, a genome-wide association analysis revealed that two consecutive genes encoding a hemerythrin-like protein and a nitroreductase-like protein were significantly associated with pathogenicity. These two genes may be involved in the resistance to reactive oxygen and nitrogen species, a required mechanism for the intracellular survival of bacteria. Three non-pathogenic M. kansasii lacked these genes likely due to two distinct distributive conjugal transfers (DCTs) between M. attenuatum and M. kansasii, and one DCT between M. persicum and M. kansasii. To our knowledge, this is the first study linking DCT to reduced pathogenicity.

scholarly journals A novel putative microtubule-associated protein is involved in arbuscule development during arbuscular mycorrhiza formation

2021 ◽  
Author(s):  
Tania Ho-Plágaro ◽  
Raúl Huertas ◽  
María I Tamayo-Navarrete ◽  
Elison Blancaflor ◽  
Nuria Gavara ◽  
...  
Keyword(s):  
Plant Root ◽  
Arbuscular Mycorrhizal ◽  
Host Cells ◽  
Root Cells ◽  
Filament Dynamics ◽  
Fungal Structure ◽  
Genes Encoding ◽  
Associated Proteins ◽  
Mycorrhizal Development

Abstract The formation of arbuscular mycorrhizal (AM) symbiosis requires plant root host cells to undergo major structural and functional reprogramming in order to house the highly branched AM fungal structure for the reciprocal exchange of nutrients. These morphological modifications are associated with cytoskeleton remodelling. However, molecular bases and the role of microtubules (MTs) and actin filament dynamics during AM formation are largely unknown. In this study, the tomato tsb gene, belonging to a Solanaceae group of genes encoding MT-associated proteins for pollen development, was found to be highly expressed in root cells containing arbuscules. At earlier stages of mycorrhizal development, tsb overexpression enhanced the formation of highly developed and transcriptionally active arbuscules, while tsb silencing hampers the formation of mature arbuscules and represses arbuscule functionality. However, at later stages of mycorrhizal colonization, tsb OE roots accumulate fully developed transcriptionally inactive arbuscules, suggesting that the collapse and turnover of arbuscules might be impaired by TSB accumulation. Imaging analysis of the MT cytoskeleton in cortex root cells overexpressing tsb revealed that TSB is involved in MT-bundling. Taken together, our results provide unprecedented insights into the role of novel MT-associated protein in MT rearrangements throughout the different stages of the arbuscule life cycle.

scholarly journals Molecular cloning of cellular genes encoding retinoblastoma-associated proteins: identification of a gene with properties of the transcription factor E2F.

1992 ◽  
Vol 12 (12) ◽  
pp. 5620-5631 ◽  
Author(s):  
B Shan ◽  
X Zhu ◽  
P L Chen ◽  
T Durfee ◽  
Y Yang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Mammalian Cells ◽  
Leucine Zipper ◽  
T Antigen ◽  
Transactivation Domain ◽  
Recognition Sequence ◽  
Cellular Genes ◽  
Genes Encoding ◽  
Associated Proteins ◽  
Transcription Factor E2f

The retinoblastoma protein interacts with a number of cellular proteins to form complexes which are probably crucial for its normal physiological function. To identify these proteins, we isolated nine distinct clones by direct screening of cDNA expression libraries using purified RB protein as a probe. One of these clones, Ap12, is expressed predominantly at the G1-S boundary and in the S phase of the cell cycle. The nucleotide sequence of Ap12 has features characteristic of transcription factors. The C-terminal region binds to unphosphorylated RB in regions similar to those to which T antigen binds and contains a transactivation domain. A region containing a potential leucine zipper flanked by basic residues is able to bind an E2F recognition sequence specifically. Expression of Ap12 in mammalian cells significantly enhances E2F-dependent transcriptional activity. These results suggest that Ap12 encodes a protein with properties known to be characteristic of transcription factor E2F.

scholarly journals Genome-Wide Identification of Francisella tularensis Virulence Determinants

2007 ◽  
Vol 75 (6) ◽  
pp. 3089-3101 ◽  
Author(s):  
Jingliang Su ◽  
Jun Yang ◽  
Daimin Zhao ◽  
Thomas H. Kawula ◽  
Jeffrey A. Banas ◽  
...  
Keyword(s):  
Francisella Tularensis ◽  
Stress Responses ◽  
Small Subset ◽  
Virulence Determinants ◽  
Genome Wide ◽  
Genes Encoding ◽  
Capsule Locus ◽  
Life Threatening ◽  
Transposon Mutants ◽  
Schu S4

ABSTRACT Francisella tularensis is a gram-negative pathogen that causes life-threatening infections in humans and has potential for use as a biological weapon. The genetic basis of the F. tularensis virulence is poorly understood. This study screened a total of 3,936 transposon mutants of the live vaccine strain for infection in a mouse model of respiratory tularemia by signature-tagged mutagenesis. We identified 341 mutants attenuated for infection in the lungs. The transposon disruptions were mapped to 95 different genes, virtually all of which are also present in the genomes of other F. tularensis strains, including human pathogenic F. tularensis strain Schu S4. A small subset of these attenuated mutants carried insertions in the genes encoding previously known virulence factors, but the majority of the identified genes have not been previously linked to F. tularensis virulence. Among these are genes encoding putative membrane proteins, proteins associated with stress responses, metabolic proteins, transporter proteins, and proteins with unknown functions. Several attenuated mutants contained disruptions in a putative capsule locus which partially resembles the poly-γ-glutamate capsule biosynthesis locus of Bacillus anthracis, the anthrax agent. Deletional mutation analysis confirmed that this locus is essential for F. tularensis virulence.

scholarly journals Cloning, Sequencing, and Characterization of a Gene Cluster Involved in EDTA Degradation from the Bacterium BNC1

2001 ◽  
Vol 67 (2) ◽  
pp. 688-695 ◽  
Author(s):  
Jan Bohuslavek ◽  
Jason W. Payne ◽  
Yong Liu ◽  
Harvey Bolton ◽  
Luying Xun
Keyword(s):  
Gene Cluster ◽  
Genomic Library ◽  
Regulatory Protein ◽  
Chelating Agent ◽  
Environmental Pollutant ◽  
Flavin Mononucleotide ◽  
Bacterial Strains ◽  
System A ◽  
Monooxygenase Gene ◽  
Genes Encoding

ABSTRACT EDTA is a chelating agent, widely used in many industries. Because of its ability to mobilize heavy metals and radionuclides, it can be an environmental pollutant. The EDTA monooxygenases that initiate EDTA degradation have been purified and characterized in bacterial strains BNC1 and DSM 9103. However, the genes encoding the enzymes have not been reported. The EDTA monooxygenase gene was cloned by probing a genomic library of strain BNC1 with a probe generated from the N-terminal amino acid sequence of the monooxygenase. Sequencing of the cloned DNA fragment revealed a gene cluster containing eight genes. Two of the genes, emoA and emoB, were expressed inEscherichia coli, and the gene products, EmoA and EmoB, were purified and characterized. Both experimental data and sequence analysis showed that EmoA is a reduced flavin mononucleotide-utilizing monooxygenase and that EmoB is an NADH:flavin mononucleotide oxidoreductase. The two-enzyme system oxidized EDTA to ethylenediaminediacetate (EDDA) and nitrilotriacetate (NTA) to iminodiacetate (IDA) with the production of glyoxylate. TheemoA and emoB genes were cotranscribed when BNC1 cells were grown on EDTA. Other genes in the cluster encoded a hypothetical transport system, a putative regulatory protein, and IDA oxidase that oxidizes IDA and EDDA. We concluded that this gene cluster is responsible for the initial steps of EDTA and NTA degradation.

scholarly journals TRAPPopathies: An emerging set of disorders linked to variations in the genes encoding transport protein particle (TRAPP)‐associated proteins

Traffic ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 5-26 ◽  
Author(s):  
Michael Sacher ◽  
Nassim Shahrzad ◽  
Hiba Kamel ◽  
Miroslav P. Milev
Keyword(s):  
Transport Protein ◽  
Genes Encoding ◽  
Associated Proteins ◽  
Protein Particle

Hypertrophic cardiomyopathy: genetics

ESC CardioMed ◽  
2018 ◽  
pp. 1443-1450
Author(s):  
Mohammed Majid Akhtar ◽  
Luis Rocha Lopes
Keyword(s):  
Genetic Testing ◽  
Hypertrophic Cardiomyopathy ◽  
Mapk Pathway ◽  
Glycogen Storage ◽  
Cellular Level ◽  
Causative Mutation ◽  
Clinical Role ◽  
Genes Encoding ◽  
Associated Proteins

Hypertrophic cardiomyopathy is most commonly transmitted as an autosomal dominant trait, caused by mutations in genes encoding cardiac sarcomere and associated proteins. Knowledge of the genetic pathophysiology of the disease has advanced significantly since the initial identification of a point mutation in the beta-myosin heavy chain (MYH7) gene in 1990. Other genetic causes of the disease include mutations in genes coding for proteins implicated in calcium handling or which form part of the cytoskeleton. The recent emergence of next-generation sequencing allows quicker and less expensive identification of causative mutations. However, a causative mutation is not identified in up to 50% of probands. At present, the primary clinical role of genetic testing in hypertrophic cardiomyopathy is in the context of familial screening, allowing the identification of those at risk of developing the condition. Genetic testing can also be used to exclude genocopies, particularly in the presence of certain diagnostic ‘red flag’ features, where lysosomal, glycogen storage, neuromuscular or Ras-MAPK pathway disorders may be suspected. The role of individual mutations in predicting prognosis is limited at present. However, the higher incidence of sudden cardiac death in the presence of a family history of such, suggests that genetics play a significant role in determining outcome. With an increased understanding of the impact of these mutations on a cellular level and on longer-term clinical outcomes, the aim in future for gene and mutation specific prognosis or potential disease-modifying therapy is closer.

scholarly journals Genome-Wide Screen of Salmonella Genes Expressed during Infection in Pigs, Using In Vivo Expression Technology

2007 ◽  
Vol 73 (23) ◽  
pp. 7522-7530 ◽  
Author(s):  
Yanyan Huang ◽  
Christopher L. Leming ◽  
Mitsu Suyemoto ◽  
Craig Altier
Keyword(s):  
Genomic Library ◽  
Clinical Signs ◽  
Great Majority ◽  
Dna Fragments ◽  
Environmental Signals ◽  
Genome Wide ◽  
Serovar Typhimurium ◽  
Genes Encoding ◽  
Elevated Expression

ABSTRACT Pigs are a food-producing species that readily carry Salmonella but, in the great majority of cases, do not show clinical signs of disease. Little is known about the functions required by Salmonella to be maintained in pigs. We have devised a recombinase-based promoter-trapping strategy to identify genes with elevated expression during pig infection with Salmonella enterica serovar Typhimurium. A total of 55 clones with in vivo-induced promoters were selected from a genomic library of ∼10,000 random Salmonella DNA fragments fused to the recombinase cre, and the cloned DNA fragments were analyzed by sequencing. Thirty-one genes encoding proteins involved in bacterial adhesion and colonization (including bcfA, hscA, rffG, and yciR), virulence (metL), heat shock (hscA), and a sensor of a two-component regulator (hydH) were identified. Among the 55 clones, 19 were isolated from both the tonsils and the intestine, while 23 were identified only in the intestine and 13 only in tonsils. High temperature and increased osmolarity were identified as environmental signals that induced in vivo-expressed genes, suggesting possible signals for expression.

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