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Query: EC:2.7.7.49 (
reverse transcriptase
)
31,746
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The effect of high-level expression of the regulatory gene xylS of the
Pseudomonas
putida TOL plasmid on the activation of the xylDLEGF operon was investigated in Escherichia coli. The xylS gene was placed downstream from the tac promoter, and the resultant fusion was cloned in cis to the xylDLEGF operon. The expression of the operon was monitored by the level of catechol 2,3-dioxygenase, whose structural gene xylE was placed directly after the operator-promoter region of xylDLEGF. xylS transcription was also determined by
reverse transcriptase
mapping of mRNA. Overproduction of the xylS gene product elicited constitutive high expression of the xylDLEGF operon even in the absence of the inducer for the operon. The results were consistent with a cascade model for the positive control of the xylDLEGF operon by the xylR and xylS genes (S. Inouye, A. Nakazawa, and T. Nakazawa, Proc. Natl. Acad. Sci. USA, in press): m-xylene, a substrate of the degradative pathway, binds to the xylR gene product; the m-xylene-xylR product complex activates the xylS gene; and the xylS product thus synthesized de novo activates the xylDLEGF operon.
...
PMID:Overproduction of the xylS gene product and activation of the xylDLEGF operon on the TOL plasmid. 361 Oct 23
The transcription initiation site of the xylDEGF operon on the TOL plasmid of
Pseudomonas
putida mt-2 was determined in P. putida and in Escherichia coli by S1 nuclease and
reverse transcriptase
mapping. The induced synthesis of mRNA started at the same start point in both P. putida and E. coli, although the amount of mRNA in E. coli cells was less than that in P. putida. The nucleotide sequence of the region surrounding the start point was also determined. The ribosome-binding site (RBS) complementary to the 3' end of the 16S rRNA of
Pseudomonas
aeruginosa and E. coli preceded the predicted start codon for the xylD gene. The consensus nucleotide sequence for E. coli promoters was not found in the region preceding the transcription start point. On the other hand, the sequences of the "-10" and the "-35" regions of the xylDEGF operon revealed some homology with the respective, previously determined sequences of the xylABC operon of the TOL plasmid.
...
PMID:Nucleotide sequence of the promoter region of the xylDEGF operon on TOL plasmid of Pseudomonas putida. 609 37
The xylABC operon on the TOL plasmid directs the synthesis of enzymes for conversion of toluene to benzoate and is positively controlled by the regulatory gene xylR. In the study here the nucleotide sequence was determined for the regulatory region of this operon. The in vivo transcription initiation site of the operon was determined by S1 nuclease and
reverse transcriptase
mapping. RNA was prepared from m-methylbenzyl alcohol-induced cells of
Pseudomonas
putida and Escherichia coli carrying pTN2, a derivative of the TOL plasmid containing the structural and regulatory genes of the entire toluene-degrading pathway. The amount of E. coli mRNA was estimated to be only 10% of that of P. putida mRNA. Consensus sequences of the -10 region (Pribnow box) and the -35 region (RNA polymerase recognition site) in E. coli genes were not found in the region preceding the transcription initiation site, whereas a sequence complementary to the 3' end of the 16S rRNA of
Pseudomonas
aeruginosa and E. coli existed in front of the predicted start codon of the xylA gene. These results explain the inefficient expression of TOL genes in E. coli.
...
PMID:Nucleotide sequence surrounding transcription initiation site of xylABC operon on TOL plasmid of Pseudomonas putida. 632 12
We have used a
reverse transcriptase
polymerase chain reaction procedure (differential display) to isolate cDNAs corresponding to transcripts that accumulate in ozone-treated Arabidopsis thaliana. In this report we describe the characterization of an ozone-induced transcript, AtOZI1. AtOZI1 mRNA in untreated plants was detected at low levels in cotyledons, leaves, and flower buds and at higher levels in roots and mature flowers. AtOZI1 mRNA accumulation was transiently induced in leaves 3- to 5-fold within the first 6 h of ozone treatment. AtOZI1 mRNA accumulation was also transiently induced 3- to 6-fold by phytopathogenic
Pseudomonas
strains. Sequence analysis of AtOZI1 revealed that it encodes a 8.6 kDa basic protein that contains a putative signal peptide and two potential phosphorylation sites. Our results suggest that AtOZI1 represents a novel stress-related protein that accumulates in response to the production of active oxygen species.
...
PMID:Isolation of a novel Arabidopsis ozone-induced cDNA by differential display. 757 70
The phylogenetic relationships of 50 reference strains, mostly marine bacteria which require Na+ for growth, were determined on the basis of 600 16S rRNA nucleotides by using
reverse transcriptase
sequencing. Strains belonging to 10 genera were included (four genera of the family Vibrionaceae, the genus Aeromonas of the family Aeromonadaceae, and the genera Alteromonas, Marinomonas, Shewanella,
Pseudomonas
, and Deleya). The sequences were aligned, the similarity values and evolutionary distance values were determined, and a phylogenetic tree was constructed by using the neighbor-joining method. On the basis of our results, the family Vibrionaceae was separated into at least seven groups (genera and families). Vibrio marinus clearly was on a line of descent that was remote from other vibrios. As determined by the similarity and evolutionary distance values, V. marinus is more distantly related to the family Vibrionaceae than the members of the Aeromonadaceae are. Also, Vibrio cholerae strains formed a separate group with Vibrio mimicus at the genus level. Of 30 species of the Vibrionaceae, 17 formed a large phylogenetic cluster. The genus Listonella was found to be a heterogeneous group, and the species were distributed in various subgroups of the Vibrionaceae. The separation of the family Aeromonadaceae from the family Vibrionaceae and the separation of the genera Marinomonas and Shewanella from the genus Alteromonas were confirmed in this phylogenetic study. However, a marine
Pseudomonas
species,
Pseudomonas
nautica, was clearly separated from two terrestrial
Pseudomonas
species. Each group that was separated by the phylogenetic analysis had characteristic 16S rRNA sequence patterns that were common only to species in that group. Therefore, the characteristic sequences described in this paper may be useful for identification purposes.
...
PMID:Phylogenetic relationships of marine bacteria, mainly members of the family Vibrionaceae, determined on the basis of 16S rRNA sequences. 842 11
A modified freeze-thaw method in combination with
reverse transcriptase
PCR was developed for monitoring gene expression in activated sludge. The sensitivity of the methodology was determined by inoculating non-sterile activated sludge samples with 3-chlorobenzoate-degrading
Pseudomonas
putida PPO301(pRO103), which contains the catabolic tfdB gene. tfdB mRNA was detected in 10 mg of activated sludge inoculated with 10(4) CFU of the target organism. This technique was subsequently utilized to analyze the in situ expression of the catabolic dmpN gene in a sequencing batch reactor (SBR) bioaugmented with phenol-degrading P. putida ATCC 11172. Greatest dmpN expression was observed 15 min after maximum phenol concentration was reached in the reactor and 15 min after the start of aeration. Decreased phenol concentrations in the reactor corresponded to reduced levels of dmpN expression, although low levels of dmpN mRNA were observed throughout the SBR cycle. These results indicate that concentration of phenol in the reactor and the onset of aeration stimulated transcriptional activity of the dmpN gene. The information obtained from this study can be used to alter SBR operational strategies so as to lead to more effective bioaugmentation practices.
...
PMID:Application of reverse transcriptase PCR for monitoring expression of the catabolic dmpN gene in a phenol-degrading sequencing batch reactor. 852 13
Effective treatment is lacking for malignant glioblastoma/astrocytoma. We have identified interleukin-4 receptors (IL-4R) on human malignant astrocytoma. We demonstrate that 16 of 21 surgical samples of high-grade astrocytoma and glioblastoma but not normal brain tissues expressed IL-4R as assessed by
reverse transcriptase
PCR. We further demonstrate that human malignant astrocytoma cell lines express high-affinity IL-4R. Using a chimeric protein composed of circularly permuted IL-4 and a truncated form of
Pseudomonas
exotoxin A, we observed that this toxin IL4(38-37)-PE38KDEL) is highly cytotoxic to IL-4R-bearing glioblastoma cells. Compared with a previously reported IL4-PE chimeric protein (IL-PE4E), IL4(38-37)-PE38KDEL bound with higher affinity and was 3-30-fold more cytotoxic to glioblastoma cell lines. Upon intrathecal administration in monkeys, high cerebrospinal fluid IL4(38-37)-PE38KDEL levels were achieved using 2- and 6-microg/kg doses without any central nervous system or other abnormalities. IL4(38-37)-PE38KDEL levels were not detectable in the serum of any monkey studied. When IL4(38-37)-PE38KDEL was injected into the right frontal cortex of rats, localized necrosis was observed at 1000-ng/ml doses but not at < or = 100-ng/ml doses. We conclude that by localized administration, nontoxic levels of IL4(38-37)-PE38KDEL can be achieved, which may have significant cytotoxic activity against malignant astrocytoma.
...
PMID:Preclinical development of a recombinant toxin containing circularly permuted interleukin 4 and truncated Pseudomonas exotoxin for therapy of malignant astrocytoma. 1145 21
The roots of Ononis spinosa subsp. leiosperma (Leguminosae) afforded a new glycoside, spinonin (1), possessing a novel skeleton, in addition to the known isoflavonoid glycoside, ononin [7beta-(glucosyloxy)formononetin] (2) and the known pterocarpan, 7-demethoxy-7-D-(glucosyloxy)homopterocarpin (3). The structure of the new isolate was elucidated by spectral methods including 1H and 13C NMR, COSY, APT, HETCOR, HMBC, NOESY, CD, FABMS, HRMS, EIMS, CIMS, and some chemical reactions. Spinonin was inactive against a number of human cancer cell lines and HIV-1
reverse transcriptase
. The compounds 1 and 3 showed weak activity against
Pseudomonas
aeruginosa, whereas 2 was active against beta-hemolytic Streptococcus.
...
PMID:Spinonin, a novel glycoside from Ononis spinosa subsp. leiosperma. 918 26
The causative agent of ovine footrot, the gram-negative anaerobe Dichelobacter nodosus, produces polar type IV fimbriae, which are the major protective antigens. The D. nodosus genes fimN, fimO, and fimP are homologs of the
Pseudomonas
aeruginosa fimbrial assembly genes, pilB, pilC, and pilD, respectively. Both the pilD and fimP genes encode prepilin peptidases that are responsible for cleavage of the leader sequence from the immature fimbrial subunit. To investigate the functional similarity of the fimbrial biogenesis systems from these organisms, the D. nodosus genes were introduced into P. aeruginosa strains carrying mutations in the homologous genes. Analysis of the resultant derivatives showed that the fimP gene complemented a pilD mutant of P. aeruginosa for both fimbrial assembly and protein secretion. However, the fimN and fimO genes did not complement pilB or pilC mutants, respectively. These results suggest that although the PilD prepilin peptidase can be functionally replaced by the heterologous FimP protein, the function of the PilB and PilC proteins may require binding or catalytic domains specific for the P. aeruginosa fimbrial assembly system. The transcriptional organization and regulation of the fimNOP gene region were also examined. The results of
reverse transcriptase
PCR and primer extension analysis suggested that these genes form an operon transcribed from two sigma70-type promoters located upstream of ORFM, an open reading frame proximal to fimN. Transcription of the D. nodosus fimbrial subunit was found to increase in cells grown on solid media, and it was postulated that this regulatory effect may be of significance in the infected footrot lesion.
...
PMID:Complementation analysis of the Dichelobacter nodosus fimN, fimO, and fimP genes in Pseudomonas aeruginosa and transcriptional analysis of the fimNOP gene region. 942 71
Human tracheal gland (HTG) serous cells are now believed to play a major role in the physiopathology of cystic fibrosis. Because of the persistent inflammation and the specific infection by
Pseudomonas
aeruginosa in the lung, we looked for the action of the lipopolysaccharide (LPS) of this bacteria on human tracheal gland cells in culture by studying the secretion of the secretory leukocyte proteinase inhibitor (SLPI) which is a specific serous secretory marker of these cells. Treatment with
Pseudomonas
aeruginosa LPS resulted in a significant dose-dependent increase in the basal production of SLPI (+ 250 +/- 25%) whilst the SLPI transcript mRNA levels remained unchanged. This LPS-induced increase in secretion was inhibited by glucocorticoides. Furthermore, LPS treatment of HTG cells induces a loss of responsiveness to carbachol and isoproterenol but not to adenosine triphosphate. These findings indicate that HTG cells treated by
Pseudomonas
aeruginosa LPS have the same behavior as those previously observed with CF-HTG cells. Exploration by using
reverse transcriptase
polymerase chain reaction amplification showed that LPS downregulated cystic fibrosis transmembrane conductance regulator (CFTR) mRNA expression in HTG cells indicative of a link between CFTR function and consequent CF-like alteration in protein secretory process.
...
PMID:Pseudomonas aeruginosa lipopolysaccharide induces CF-like alteration of protein secretion by human tracheal gland cells. 942 67
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