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At least 541 records · Page 30Linked to original sources
PubMed2005

The Fed-1 (CAUU)4 element is a 5' UTR dark-responsive mRNA instability element that functions independently of dark-induced polyribosome dissociation.

Darkness rapidly induces a decline in the stability and translation of the pea Ferredoxin-1 (Fed-1) mRNA in transgenic tobacco. Direct half-life measurement showed that mutation of the (CAUU)4 stabilizes Fed-1 mRNA in the dark. (CAUU)1, a feature more common in plant 5' UTRs than (CAUU)4, confers slight light-responsive mRNA accumulation. At least three but less than 11 CAUU repeats near the 5' end of the 5' UTR are required for full light-responsive accumulation. Furthermore, 26 nt of the 5' UTR, including the (CAUU)4 repeat, is sufficient to confer a significant approximately 2.5-fold increase in light-regulated mRNA accumulation when fused to the 5' end of a heterologous plant mRNA. A mutation of the (CAUU)4 repeat that compromises light-regulated mRNA stability changes in vitro the accessibility of the region to ribonuclease V1 and ribonuclease A suggesting the geometry formed by the repeat may be important for instability. Finally, dark-induced Fed-1 mRNA instability occurs even when most of the mRNA is retained on polyribosomes, and thus is likely an independent event regulated by darkness.

5' Untranslated Regions↗
PubMed1987

Trace elements intake in the Faroe Islands. II. Intake of mercury and other elements by consumption of pilot whales (Globicephalus meleanus).

The long-term intakes of total mercury, methyl mercury and cadmium from eating pilot whale (Globicephalus meleanus) in the Faroe Islands have been estimated. The long-term intakes of both total and methyl mercury far exceed the Provisional Tolerable Weekly Intakes (PTWI) recommended by WHO. For the general population The PTWI's are 300 and 200 micrograms mercury per person per week for total and methyl mercury, respectively. The calculated intake of methyl mercury in this study approaches the lower value (1200 micrograms/person/week) of the recognized critical level of methyl mercury intoxication in the general population. In the years 1980 and 1981 the cadmium intake from consuming pilot whale foods exceeded the PTWI by a factor of 2. The PTWI for cadmium is 400-500 micrograms/person/week. It is concluded that the general Faroe Island population should significantly restrict the consumption of pilot whale foods. Pregnant women probably should not eat pilot whale foods at all, as the critical levels for methyl mercury intoxication of pregnant women and fetuses are lower by a factor of 2-5 than for the general population.

Adipose Tissue↗
PubMed2006

Impact of river overflowing on trace element contamination of volcanic soils in south Italy: part II. Soil biological and biochemical properties in relation to trace element speciation.

The effect of heavy metal contamination on biological and biochemical properties of Italian volcanic soils was evaluated in a multidisciplinary study, involving pedoenvironmental, micromorphological, physical, chemical, biological and biochemical analyses. Soils affected by recurring river overflowing, with Cr(III)-contaminated water and sediments, and a non-flooded control soil were analysed for microbial biomass, total and active fungal mycelium, enzyme activities (i.e., FDA hydrolase, dehydrogenase, beta-glucosidase, urease, arylsulphatase, acid phosphatase) and bacterial diversity (DGGE characterisation). Biological and biochemical data were related with both total and selected fractions of Cr and Cu (the latter deriving from agricultural chemical products) as well as with total and extractable organic C. The growth and activity of soil microbial community were influenced by soil organic C content rather than Cu or Cr contents. In fact, positive correlations between all studied parameters and organic C content were found. On the contrary, negative correlations were observed only between total fungal mycelium, dehydrogenase, arylsulphatase and acid phosphatase activities and only one Cr fraction (the soluble, exchangeable and carbonate bound). However, total Cr content negatively affected the eubacterial diversity but it did not determine changes in soil activity, probably because of the redundancy of functions within species of soil microbial community. On the other hand, expressing biological and biochemical parameters per unit of total organic C, Cu pollution negatively influenced microbial biomass, fungal mycelium and several enzyme activities, confirming soil organic matter is able to mask the negative effects of Cu on microbial community.

Bacteria↗
PubMed2006

Impact of river overflowing on trace element contamination of volcanic soils in south Italy: part I. Trace element speciation in relation to soil properties.

Volcanic soils affected by different numbers of polluted river flooding events were investigated. Chromium and Cu were the major soil contaminants. Nickel, Fe, Zn and Mn total content never exceeded the Italian mandatory limits. The distribution of Cr and Cu total contents among studied soils indicated that only Cr contamination was related to overflowing events. In polluted soils, sequential chemical extractions revealed a preferential association of Cr and Cu with organic forms. A progressive Cr insolubilization with ageing was observed. Significant amounts of Cr and Cu were extracted by NH(4)-oxalate, suggesting metals association with short-range-order aluminosilicates and organo-mineral complexes. Possible methodological drawbacks in the use of the EU-BCR chemical speciation protocol on volcanic soils are discussed. Micromorphology and SEM/WDS analyses revealed Cr and Cu enriched silt and clay coatings in surface and subsurface soil horizons, suggesting a transfer of metal-rich sediments along the soil pore network with water movement.

Chromium↗
PubMed2001

Angiotensin II-responsive element is the insulin-responsive element in the adipocyte fatty acid synthase gene: role of adipocyte determination and differentiation factor 1/sterol-regulatory-element-binding protein 1c.

We have previously shown that angiotensin II (Ang II) increases the expression of the gene encoding adipocyte fatty acid synthase (FAS). Here we investigate the mechanism responsible for increased FAS gene transcription by Ang II. We demonstrate that Ang II increased luciferase activity by 3-fold in 3T3-L1 adipocytes transfected with fusion constructs linking the FAS promoter to the luciferase reporter gene. Interestingly, we mapped the Ang II regulatory sequences to the insulin-responsive region (E box) in the proximal FAS promoter. The E box alone was able to mediate Ang II responsiveness when linked to a heterologous promoter. However, this response was lost when mutations that abolished the binding of the E box to its transcription factors were introduced. Using adenoviral overexpression of a dominant-negative form of adipocyte determination and differentiation factor 1 (ADD1), a transcription factor that binds to the insulin-responsive E box, we demonstrated that ADD1 was required for Ang II regulation of the FAS gene in 3T3-L1 adipocytes. Furthermore, ADD1 expression was also up-regulated by Ang II. With the use of transfections as well as glucose transport assays, we further demonstrated that Ang II stimulation of the FAS gene was dependent on glucose. In conclusion, this is the first report that Ang II regulates adipocyte FAS gene transcription via insulin response sequences in a glucose-dependent manner and that this regulation is mediated at least in part via the ADD1 transcription factor.

3T3 Cells↗