Respiratory nitrate and nitrite pathway in the denitrifier haloarchaeon Haloferax mediterranei

2006 ◽  
Vol 34 (1) ◽  
pp. 115-117 ◽  
Author(s):  
R.M. Martínez-Espinosa ◽  
D.J. Richardson ◽  
J.N. Butt ◽  
M.J. Bonete

Haloferax mediterranei cells are able to use high nitrate or nitrite concentrations as electron acceptors under anoxic conditions. The nar operon, which has eight open reading frames, has been sequenced and its regulation has been characterized at the transcriptional level. The narG and narH genes encode the Nar (respiratory nitrate reductase) catalytic subunit (NarG) and the electron transfer Nar subunit (NarH) respectively. Nar has been purified and characterized in vitro. This characterization has included protein-film voltammetry and preliminary EPR studies.

2021 ◽  
Vol 9 (5) ◽  
pp. 1005
Author(s):  
Olga Chervyakova ◽  
Elmira Tailakova ◽  
Nurlan Kozhabergenov ◽  
Sandugash Sadikaliyeva ◽  
Kulyaisan Sultankulova ◽  
...  

Capripoxviruses with a host range limited to ruminants have the great potential to be used as vaccine vectors. The aim of this work was to evaluate attenuated sheep pox virus (SPPV) vaccine strain NISKHI as a vector expressing several genes. Open reading frames SPPV020 (ribonucleotide kinase) and SPPV066 (thymidine kinase) were selected as sites for the insertion of foreign genes. Two integration plasmids with expression cassette were designed and constructed. Recombinant SPPVs expressing an enhanced green fluorescent protein (EGFP) (rSPPV(RRΔ)EGFP and rSPPV(TKΔ)EGFP), Foot-and-mouth disease virus capsid protein (VP1), and Brucella spp. outer membrane protein 25 (OMP25) (rSPPV(RRΔ)VP1A-(TKΔ)OMP25) were generated under the transient dominant selection method. The insertion of foreign genes into the SPPV020 and SPPV066 open reading frames did not influence the replication of the recombinant viruses in the cells. Successful foreign gene expression in vitro was assessed by luminescent microscopy (EGFP) and Western blot (VP1 and OMP25). Our results have shown that foreign genes were expressed by rSPPV both in permissive (lamb testicles) and non-permissive (bovine kidney, saiga kidney, porcine kidney) cells. Mice immunized with rSPPV(RRΔ)VP1A-(TKΔ)OMP25 elicited specific antibodies to both SPPV and foreign genes VP1 and OMP25. Thus, SPPV NISKHI may be used as a potential safe immunogenic viral vector for the development of polyvalent vaccines.


2006 ◽  
Vol 80 (8) ◽  
pp. 4179-4182 ◽  
Author(s):  
Pierre Rivailler ◽  
Amitinder Kaur ◽  
R. Paul Johnson ◽  
Fred Wang

ABSTRACT A pathogenic isolate of rhesus cytomegalovirus (rhCMV 180.92) was cloned, sequenced, and annotated. Comparisons with the published rhCMV 68.1 genome revealed 8 open reading frames (ORFs) in isolate 180.92 that are absent in 68.1, 10 ORFs in 68.1 that are absent in 180.92, and 34 additional ORFs that were not previously annotated. Most of the differences appear to be due to genetic rearrangements in both isolates from a region that is frequently altered in human CMV (hCMV) during in vitro passage. These results indicate that the rhCMV ORF repertoire is larger than previously recognized. Like hCMV, understanding of the complete coding capacity of rhCMV is complicated by genomic instability and may require comparisons with additional isolates in vitro and in vivo.


Blood ◽  
1999 ◽  
Vol 93 (9) ◽  
pp. 2936-2944 ◽  
Author(s):  
Ramachandran Ramalingam ◽  
Shahin Rafii ◽  
Stefan Worgall ◽  
Douglas E. Brough ◽  
Ronald G. Crystal

Abstract Although endothelial cells are quiescent and long-lived in vivo, when they are removed from blood vessels and cultured in vitro they die within days to weeks. In studies of the interaction of E1−E4+ replication–deficient adenovirus (Ad) vectors and human endothelium, the cells remained quiescent and were viable for prolonged periods. Evaluation of these cultures showed that E1−E4+ Ad vectors provide an “antiapoptotic” signal that, in association with an increase in the ratio of Bcl2 to Bax levels, induces the endothelial cells to enter a state of “suspended animation,” remaining viable for at least 30 days, even in the absence of serum and growth factors. Although the mechanisms initiating these events are unclear, the antiapoptoic signal requires the presence of E4 genes in the vector genome, suggesting that one or more E4 open reading frames of subgroup C Ad initiate a “pro-life” program that modifies cultured endothelial cells to survive for prolonged periods.


2003 ◽  
Vol 77 (20) ◽  
pp. 11268-11273 ◽  
Author(s):  
Nikolai Klymiuk ◽  
Mathias Müller ◽  
Gottfried Brem ◽  
Bernhard Aigner

ABSTRACT Endogenous retrovirus (ERV) sequences have been found in all mammals. In vitro and in vivo experiments revealed ERV activation and cross-species infection in several species. Sheep (Ovis aries) are used for various biotechnological purposes; however, they have not yet been comprehensively screened for ERV sequences. Therefore, the aim of the study was to classify the ERV sequences in the ovine genome (OERV) by analyzing the retroviral pro-pol sequences. Three OERV β families and nine OERV γ families were revealed. Novel open reading frames (ORF) in the amplified proviral fragment were found in one OERV β family and two OERV γ families. Hybrid OERV produced by putative recombination events were not detected. Quantitative analysis of the OERV sequences in the ovine genome revealed no relevant variations in the endogenous retroviral loads of different breeds. Expression analysis of different tissues from fetal and pregnant sheep detected mRNA from both gammaretrovirus families, showing ORF fragments. Thus, the release of retroviruses from sheep cells cannot be excluded.


2003 ◽  
Vol 185 (7) ◽  
pp. 2285-2295 ◽  
Author(s):  
Andrea Möllenkvist ◽  
Therése Nordström ◽  
Christer Halldén ◽  
Jens Jørgen Christensen ◽  
Arne Forsgren ◽  
...  

ABSTRACT The prevalence of the Moraxella catarrhalis immunoglobulin D (IgD)-binding outer membrane protein MID and its gene was determined in 91 clinical isolates and in 7 culture collection strains. Eighty-four percent of the clinical Moraxella strains expressed MID-dependent IgD binding. The mid gene was detected in all strains as revealed by homology of the signal peptide sequence and a conserved area in the 3′ end of the gene. When MID proteins from five different strains were compared, an identity of 65.3 to 85.0% and a similarity of 71.2 to 89.1% were detected. Gene analyses showed several amino acid repeat motifs in the open reading frames, and MID could be called a putative autotransport protein. Interestingly, homopolymeric {polyguanine [poly(G)]} tracts were detected at the 5′ ends within the open reading frames. By flow cytometry, using human IgD and fluorescein isothiocyanate-conjugated anti-IgD polyclonal antibodies, most strains showed two peaks: one high- and one low-intensity peak. All isolates expressing high levels of MID had 1, 2, or 3 triplets of G's in their poly(G) tracts, while strains not expressing MID had 4, 7, 8, or 10 G’s in their poly(G) tracts or point mutations causing a putative preterminated translation. Northern blot analysis revealed that the mid gene was regulated at the transcriptional level. Experiments with nonclumping variants of M. catarrhalis proved that bacteria lost their MID expression by removing a G in their poly(G) tracts. Moraxella strains isolated from the nasopharynx or from blood and sputum specimens expressed MID at approximately the same frequency. In addition, no variation was observed between strains of different geographical origins (Australia, Europe, Japan, or the United States). MID and the mid gene were found solely in M. catarrhalis, whereas related Neisseria and Moraxella species did not express MID. Taken together, MID appears to be a conserved protein that can be found in essentially all M. catarrhalis strains. Furthermore, MID is governed by poly(G) tracts when bacteria undergo phase variation.


1994 ◽  
Vol 14 (7) ◽  
pp. 4485-4492 ◽  
Author(s):  
B A Dombroski ◽  
Q Feng ◽  
S L Mathias ◽  
D M Sassaman ◽  
A F Scott ◽  
...  

L1 elements constitute a highly repetitive human DNA family (50,000 to 100,000 copies) lacking long terminal repeats and ending in a poly(A) tail. Some L1 elements are capable of retrotransposition in the human genome (Kazazian, H. H., Jr., C. Wong, H. Youssoufian, A. F. Scott, D. G. Phillips, and S.E. Antonarakis, Nature (London) 332:164-166, 1988). Although most are 5' truncated, a consensus sequence of complete L1 elements is 6 kb long and contains two open reading frames (ORFs) (Scott, A. F., B. J. Schmeckpeper, M. Abdelrazik, C. T. Comey, B. O'Hara, J. P. Rossiter, T. Cooley, P. Health, K. D. Smith, and L. Margolet, Genomics 1:113-125, 1987). The protein encoded by ORF2 has reverse transcriptase (RT) activity in vitro (Mathias, S. L., A. F. Scott, H. H. Kazazian, Jr., J. D. Boeke, and A. Gabriel, Science 254:1808-1810, 1991). Because L1 elements are so numerous, efficient methods for identifying active copies are required. We have developed a simple in vivo assay for the activity of L1 RT based on the system developed by Derr et al. (Derr, L. K., J. N. Strathern, and D. J. Garfinkel, Cell 67:355-364, 1991) for yeast HIS3 pseudogene formation. L1 ORF2 displays an in vivo RT activity similar to that of yeast Ty1 RT in this system and generates pseudogenes with unusual structures. Like the HIS3 pseudogenes whose formation depends on Ty1 RT, the HIS3 pseudogenes generated by L1 RT are joined to Ty1 sequences and often are part of complex arrays of Ty1 elements, multiple HIS3 pseudogenes, and hybrid Ty1/L1 elements. These pseudogenes differ from those previously described in that there are base pairs of unknown origin inserted at several of the junctions. In two of three HIS3 pseudogenes studied, the L1 RT appears to have jumped from the 5' end of a Ty1/L1 transcript to the poly(A) tract of the HIS3 RNA.


1991 ◽  
Vol 11 (9) ◽  
pp. 4306-4313 ◽  
Author(s):  
B A Arrick ◽  
A L Lee ◽  
R L Grendell ◽  
R Derynck

We have cloned and sequenced the 5' untranslated region of the transforming growth factor-beta 3 (TGF-beta 3) mRNA as well as the adjacent genomic sequence. S1 nuclease analysis identified a single transcription start site. We have thus determined that the 5' untranslated region is about 1.1 kb long and contains 11 open reading frames. In vitro translation of the TGF-beta 3 precursor coding sequence was markedly inhibited by the presence of the 5' untranslated region. Similarly, when the 5' untranslated region of TGF-beta 3 was introduced upstream of the coding sequence of chloramphenicol acetyltransferase, in vitro translation was inhibited. Furthermore, upon transfection into 293 cells, chloramphenicol acetyltransferase expression was inhibited by the 5' untranslated region of TGF-beta 3. The degree of translational inhibition was inversely proportional to the amount of transfected DNA. Mutation analysis implicated multiple segments of the 5' untranslated region as contributing to the inhibitory effect. Deletion of much of the 5'-most 640 nucleotides, including 8 of the 11 upstream ATGs, relieved much but not all of the inhibitory influence of the 5' untranslated region of TGF-beta 3 mRNA. The two upstream open reading frames closest to the initiator codon for the TGF-beta 3 coding sequence also decreased translational efficiency, since mutation of either ATG resulted in increased translation. Transfection results with T47-D cells, a cell line which expresses TGF-beta 3 mRNA, were similar to those obtained with the 293 cell line. Thus, TGF-beta 3 mRNA is a recent example of an expanding group of growth-related mRNAs in which the 5' untranslated region contains upstream open reading frames and other sequences which inhibit translation.


2001 ◽  
Vol 183 (8) ◽  
pp. 2425-2430 ◽  
Author(s):  
Frederik Börnke ◽  
Mohammad Hajirezaei ◽  
Uwe Sonnewald

ABSTRACT Erwinia rhapontici is able to convert sucrose into isomaltulose (palatinose, 6-O-α-d-glucopyranosyl-d-fructose) and trehalulose (1-O-α-d-glucopyranosyl-d-fructose) by the activity of a sucrose isomerase. These sucrose isomers cannot be metabolized by plant cells and most other organisms and therefore are possibly advantageous for the pathogen. This view is supported by the observation that in vitro yeast invertase activity can be inhibited by palatinose, thus preventing sucrose consumption. Due to the lack of genetic information, the role of sucrose isomers in pathogenicity has not been evaluated. Here we describe for the first time the cloning and characterization of the palatinose (pal) genes fromErwinia rhapontici. To this end, a 15-kb chromosomal DNA fragment containing nine complete open reading frames (ORFs) was cloned. The pal gene products of Erwinia rhapontici were shown to be homologous to proteins involved in uptake and metabolism of various sugars from other microorganisms. ThepalE, palF, palG, palH, palK, palQ, and palZgenes were oriented divergently with respect to the palRand palI genes, and sequence analysis suggested that the first set of genes constitutes an operon. Northern blot analysis of RNA extracted from bacteria grown under various conditions implies that the expression of the palI gene and the palEFGHKQZgenes is oppositely regulated at the transcriptional level. Genes involved in palatinose uptake and metabolism are down regulated by sucrose and activated by palatinose. Palatinose activation is inhibited by sucrose. Functional expression of palI andpalQ in Escherichia coli revealed sucrose isomerase and palatinase activity, respectively.


2021 ◽  
Vol 11 ◽  
Author(s):  
Eoin Dervan ◽  
Dibyangana D. Bhattacharyya ◽  
Jake D. McAuliffe ◽  
Faizan H. Khan ◽  
Sharon A. Glynn

Human endogenous retroviruses (HERV), ancient integrations of exogenous viruses, make up 8% of our genome. Long thought of as mere vestigial genetic elements, evidence is now accumulating to suggest a potential functional role in numerous pathologies including neurodegenerative diseases, autoimmune disorders, and multiple cancers. The youngest member of this group of transposable elements is HERV-K (HML-2). Like the majority of HERV sequences, significant post-insertional mutations have disarmed HERV-K (HML-2), preventing it from producing infectious viral particles. However, some insertions have retained limited coding capacity, and complete open reading frames for all its constituent proteins can be found throughout the genome. For this reason HERV-K (HML-2) has garnered more attention than its peers. The tight epigenetic control thought to suppress expression in healthy tissue is lost during carcinogenesis. Upregulation of HERV-K (HML-2) derived mRNA and protein has been reported in a variety of solid and liquid tumour types, and while causality has yet to be established, progressively more data are emerging to suggest this phenomenon may contribute to tumour growth and metastatic capacity. Herein we discuss its potential utility as a diagnostic tool and therapeutic target in light of the current in vitro, in vivo and clinical evidence linking HERV-K (HML-2) to tumour progression.


2019 ◽  
Author(s):  
Stefania Pacini ◽  
Marco Ruggiero

AbstractBacteriophages (phages), Earth’s most numerous biological entities, are natural constituents of alimentary matrices; in this study we describe the characterization of phage populations in a product obtained by fermentation of bovine milk and colostrum. Such characterizations were achieved using a microarray consisting of a chip covered in short DNA sequences that are specific to certain target organisms for a total of approximately 12,000 species. The only viruses evidenced by the array belonged to Siphoviridae, the largest phage family that targets bacteria and archea. The array yielded 27 iterations corresponding to a unique target. We discuss the putative role of some open reading frames of these phages in conferring health-supporting properties with particular reference to cells signaling and neurological development. We also describe the in vitro interaction of this fermented product with alpha-N-acetylgalactosaminidase, an enzyme whose activity in serum is elevated in neurodevelopmental disorders.


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