67 research outputs found
A promoter region that controls basal and elicitor-inducible expression levels of the NADPH: cytochrome P450 reductase gene (Cpr) from Catharanthus roseus binds nuclear factor GT-1
NADPH:cytochrome P450 reductase (CPR) is
essential for the activation of cytochrome P450 enzymes,
which are involved in a wide variety of metabolic
pathways in plants, including those related to defence
responses. In the subtropical plant Catharanthus roseus
several cytochrome P450 enzymes operate in the biosynthesis of defence-related terpenoid indole alkaloids
(TIAs). In agreement with the importance of CPR in
defence, Cpr mRNA levels in C. roseus were found to be
enhanced by fungal elicitor preparations that also induce
TIA biosynthesis and P450 gene expression. Here we
describe the isolation of a C. roseus genomic DNA clone
covering the 5¢ part of the Cpr gene and 1.6-kb of upstream sequences. Mapping of the transcription start site
showed the untranslated leader sequence is approximately 280 bp long. To study the control of gene expression by the Cpr promoter, transcriptional fusions
between Cpr promoter fragments and the gusA reporter
gene were generated and their expression was analyzed
in stably transformed tobacco plants. The Cpr promoter
fragment extending from )1510 to )8, with respect to
the ATG start codon, conferred basal and elicitor-inducible expression on the gusA reporter gene, strongly
indicating that the Cpr gene of C. roseus is indeed controlled by this promoter region. Progressive deletion
from the 5¢ end of the promoter to position )632 had little e ect on gusA expression. However, deletion to
position )366 resulted in a complete loss of basal activity and largely eliminated elicitor-induced expression,
indicating that the region from )632 to )366 contains
the main transcription-enhancing cis-regulatory sequences. Electrophoretic mobility shift assays with tobacco nuclear extracts showed that binding sites for
nuclear factor GT-1 are redundant in the Cpr promoter,
but absent from the downstream part of the leader sequence. The presence of strong GT-1 binding sites in the
main enhancer region ()632 to )366), is suggestive of a
functional role for this factor in basal expression and
elicitor responsiveness of the Cpr promoter.info:eu-repo/semantics/publishedVersio
A promoter region that controls basal and elicitor-inducible expression levels of the NADPH: cytochrome P450 reductase gene (Cpr) from Catharanthus roseus binds nuclear factor GT-1
NADPH:cytochrome P450 reductase (CPR) is
essential for the activation of cytochrome P450 enzymes,
which are involved in a wide variety of metabolic
pathways in plants, including those related to defence
responses. In the subtropical plant Catharanthus roseus
several cytochrome P450 enzymes operate in the biosynthesis of defence-related terpenoid indole alkaloids
(TIAs). In agreement with the importance of CPR in
defence, Cpr mRNA levels in C. roseus were found to be
enhanced by fungal elicitor preparations that also induce
TIA biosynthesis and P450 gene expression. Here we
describe the isolation of a C. roseus genomic DNA clone
covering the 5¢ part of the Cpr gene and 1.6-kb of upstream sequences. Mapping of the transcription start site
showed the untranslated leader sequence is approximately 280 bp long. To study the control of gene expression by the Cpr promoter, transcriptional fusions
between Cpr promoter fragments and the gusA reporter
gene were generated and their expression was analyzed
in stably transformed tobacco plants. The Cpr promoter
fragment extending from )1510 to )8, with respect to
the ATG start codon, conferred basal and elicitor-inducible expression on the gusA reporter gene, strongly
indicating that the Cpr gene of C. roseus is indeed controlled by this promoter region. Progressive deletion
from the 5¢ end of the promoter to position )632 had little e ect on gusA expression. However, deletion to
position )366 resulted in a complete loss of basal activity and largely eliminated elicitor-induced expression,
indicating that the region from )632 to )366 contains
the main transcription-enhancing cis-regulatory sequences. Electrophoretic mobility shift assays with tobacco nuclear extracts showed that binding sites for
nuclear factor GT-1 are redundant in the Cpr promoter,
but absent from the downstream part of the leader sequence. The presence of strong GT-1 binding sites in the
main enhancer region ()632 to )366), is suggestive of a
functional role for this factor in basal expression and
elicitor responsiveness of the Cpr promoter.info:eu-repo/semantics/publishedVersio
Translation controls the expression level of a chimaeric reporter gene
Transcriptional and translational fusions between the reading frame of the β-D-glucuronidase gene (gusA) and the 2′ as well as the 1′ promoter of mannopine synthase (mas), a TR locus of Agrobacterium tumefaciens, were made. The expression of these constructs was studied in the transgenic F1 offspring of independent tobacco transformants at the protein level by assaying for GUS activity and western blot analysis of the GUS protein and at the steady-state mRNA level. In leaves, stems and roots no correlation was found between steady-state levels of GUS mRNA and enzyme activity. In older tissues significantly higher GUS activities were found. This is explained by the stable character of the GUS protein together with an accumulation of protein upon ageing. Three to ten times higher GUS activities were found for in vitro grown plants than for greenhouse-grown plants of the same offspring, despite similar levels of GUS mRNA. Roots from in vitro grown plants display three to ten times higher GUS activities than stems and leaves. In transgenic plants grown in vitro, containing a translational fusion with two AUGs in phase, the initiation of translation in leaf material occurred at both AUGs. Initiation of translation at the first AUG, however, was ten times more frequent. In contrast, initiation in roots from in vitro grown plants occurred exclusively at the second AUG
Socioeconomic status in childhood and C reactive protein in adulthood: a systematic review and meta-analysis
Inflammation plays a central role in cardio-metabolic disease and may represent a mechanism linking low socioeconomic status (SES) in early life and adverse cardio-metabolic health outcomes in later life. Accumulating evidence suggests an association between childhood SES and adult inflammation, but findings have been inconsistent
Alkaloid Concentrations of Lolium perenne Infected with Epichloë festucae var. lolii with Different Detection Methods—A Re-Evaluation of Intoxication Risk in Germany?
Mycotoxins in agriculturally used plants can cause intoxication in
animals and can lead to severe financial losses for farmers. The
endophytic fungus Epichloë festucae var. lolii living symbiotically within the cool season grass species Lolium perenne
can produce vertebrate and invertebrate toxic alkaloids. Hence, an
exact quantitation of alkaloid concentrations is essential to determine
intoxication risk for animals. Many studies use different methods to
detect alkaloid concentrations, which complicates the comparability. In
this study, we showed that alkaloid concentrations of individual plants
exceeded toxicity thresholds on real world grasslands in Germany, but
not on the population level. Alkaloid concentrations on five German
grasslands with high alkaloid levels peaked in summer but were also
below toxicity thresholds on population level. Furthermore, we showed
that alkaloid concentrations follow the same seasonal trend, regardless
of whether plant fresh or dry weight was used, in the field and in a
common garden study. However, alkaloid concentrations were around three
times higher when detected with dry weight. Finally, we showed that
alkaloid concentrations can additionally be biased to different alkaloid
detection methods. We highlight that toxicity risks should be analyzed
using plant dry weight, but concentration trends of fresh weight are
reliable.
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Higher order glass-transition singularities in colloidal systems with attractive interactions
The transition from a liquid to a glass in colloidal suspensions of particles
interacting through a hard core plus an attractive square-well potential is
studied within the mode-coupling-theory framework. When the width of the
attractive potential is much shorter than the hard-core diameter, a reentrant
behavior of the liquid-glass line, and a glass-glass-transition line are found
in the temperature-density plane of the model. For small well-width values, the
glass-glass-transition line terminates in a third order bifurcation point, i.e.
in a A_3 (cusp) singularity. On increasing the square-well width, the
glass-glass line disappears, giving rise to a fourth order A_4 (swallow-tail)
singularity at a critical well width. Close to the A_3 and A_4 singularities
the decay of the density correlators shows stretching of huge dynamical
windows, in particular logarithmic time dependence.Comment: 19 pages, 12 figures, Phys. Rev. E, in prin
Nonergodicity transitions in colloidal suspensions with attractive interactions
The colloidal gel and glass transitions are investigated using the idealized
mode coupling theory (MCT) for model systems characterized by short-range
attractive interactions. Results are presented for the adhesive hard sphere and
hard core attractive Yukawa systems. According to MCT, the former system shows
a critical glass transition concentration that increases significantly with
introduction of a weak attraction. For the latter attractive Yukawa system, MCT
predicts low temperature nonergodic states that extend to the critical and
subcritical region. Several features of the MCT nonergodicity transition in
this system agree qualitatively with experimental observations on the colloidal
gel transition, suggesting that the gel transition is caused by a low
temperature extension of the glass transition. The range of the attraction is
shown to govern the way the glass transition line traverses the phase diagram
relative to the critical point, analogous to findings for the fluid-solid
freezing transition.Comment: 11 pages, 7 figures; to be published in Phys. Rev. E (1 May 1999
VIP Regulates the Development & Proliferation of Treg in vivo in spleen
<p>Abstract</p> <p>Background</p> <p>Mounting evidence supports a key role for VIP as an anti-inflammatory agent and promoter of immune tolerance. It suppresses TNF-α and other inflammatory cytokines and chemokines, upregulates anti-inflammatory IL-10, and promotes immune tolerant cells called T regulatory (Treg) cells. VIP KO mice have recently been demonstrated to have spontaneous airway and pulmonary perivascular inflammatory responses, as part of asthma-like and pulmonary hypertension phenotypes, respectively. Both inflammatory responses are correctable with VIP. Focusing on this model, we have now investigated the influence of VIP not only on inflammatory cells but also on Treg cells.</p> <p>Methods</p> <p>Using flow cytometric analysis, we examined the relative preponderance of CD25+CD4+ cells and anti-inflammatory Treg cells, in extracts of thymus and spleen from VIP KO mice (5 VIP KO; 5 VIP KO+ VIP; 10 wild-type). This method allowed antibody-based flow cytometric identification of Treg cells using surface markers CD25 and CD4, along with the: 1) intracellular activation marker FoxP3; and 2) Helios, which distinguishes cells of thymic versus splenic derivation.</p> <p>Conclusions</p> <p>Deletion of the VIP gene results in: 1) CD25+CD4- cell accumulation in the thymus, which is corrected by VIP treatment; 2) more Treg in thymus lacking Foxp3 expression, suggesting VIP is necessary for immune tolerance; and, 3) a tendency towards deficiency of Treg cells in the spleen, which is normalized by VIP treatment. Treg lacking Helios are induced by VIP intrasplenically rather than by migration from the thymus. These results confirm the dual role of VIP as an anti-inflammatory and immune tolerance-promoting agent.</p
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