scholarly journals Selenium metabolism and toxicity in the yeast Saccharomyces cerevisiae

2021 ◽  
Vol 9 (9) ◽  
Author(s):  
Myriam Lazard
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Anticancer Agents ◽  
Biological Effects ◽  
Dietary Supplementation ◽  
Biological Mechanisms ◽  
Yeast Saccharomyces Cerevisiae ◽  
Metabolic Intermediates ◽  
Selenium Metabolism ◽  
Adverse Health Effects ◽  
Higher Eukaryotes

Selenium (Se) is an essential trace element of considerable interest in humans from both a nutritional and a toxicological perspective because of the narrow margin between intakes that result in efficacy and toxicity. It is used as selenocysteine in a few selenoproteins with important physiological functions. Moreover, at supranutritional doses, Se-containing compounds have attracted interest as potential anticancer agents with high efficacy and selectivity against cancer cells. Thus, Se is becoming a widely used dietary supplement. However, accumulating evidence indicate that adverse health effects are associated with excess dietary supplementation. Therefore, characterizing the toxicity of Se metabolic intermediates are important steps to better understand both the beneficial and toxic mechanisms of Se. This review focuses on the metabolism of Se and the biological mechanisms explaining the toxicity of important Se-metabolites in the yeast Saccharomyces cerevisiae, which can be used as a model system to understand the mode of action and the biological effects of supranutritional Se in higher eukaryotes.

scholarly journals 3'-end-forming signals of yeast mRNA.

1995 ◽  
Vol 15 (11) ◽  
pp. 5983-5990 ◽  
Author(s):  
Z Guo ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cleavage Sites ◽  
Yeast Saccharomyces Cerevisiae ◽  
Higher Eukaryotes ◽  
A Site

It was previously shown that three distinct but interdependent elements are required for 3' end formation of mRNA in the yeast Saccharomyces cerevisiae: (i) the efficiency element TATATA and related sequences, which function by enhancing the efficiency of positioning elements; (ii) positioning elements, such as TTAAGAAC and AAGAA, which position the poly(A) site; and (iii) the actual site of polyadenylation. In this study, we have shown that several A-rich sequences, including the vertebrate poly(A) signal AATAAA, are also positioning elements. Saturated mutagenesis revealed that optimum sequences of the positioning element were AATAAA and AAAAAA and that this element can tolerate various extents of replacements. However, the GATAAA sequence was completely ineffective. The major cleavage sites determined in vitro corresponded to the major poly(A) sites observed in vivo. Our findings support the assumption that some components of the basic polyadenylation machinery could have been conserved among yeasts, plants, and mammals, although 3' end formation in yeasts is clearly distinct from that of higher eukaryotes.

Centromere clustering is a major determinant of yeast interphase nuclear organization

2000 ◽  
Vol 113 (11) ◽  
pp. 1903-1912 ◽  
Author(s):  
Q.W. Jin ◽  
J. Fuchs ◽  
J. Loidl
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Organization ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genome Separation ◽  
Pole Body ◽  
Opposite Pole ◽  
Somatic Pairing ◽  
Higher Eukaryotes

During interphase in the budding yeast, Saccharomyces cerevisiae, centromeres are clustered near one pole of the nucleus as a rosette with the spindle pole body at its hub. Opposite to the centromeric pole is the nucleolus. Chromosome arms extend outwards from the centromeric pole and are preferentially directed towards the opposite pole. Centromere clustering is reduced by the ndc10 mutation, which affects a kinetochore protein, and by the microtubule poison nocodazole. This suggests that clustering is actively maintained or enforced by the association of centromeres with microtubules throughout interphase. Unlike the Rabl-orientation known from many higher eukaryotes, centromere clustering in yeast is not only a relic of anaphase chromosome polarization, because it can be reconstituted without the passage of cells through anaphase. Within the rosette, homologous centromeres are not arranged in a particular order that would suggest somatic pairing or genome separation.

scholarly journals The dynamics of chromosome movement in the budding yeast Saccharomyces cerevisiae.

1989 ◽  
Vol 109 (6) ◽  
pp. 3355-3366 ◽  
Author(s):  
R E Palmer ◽  
M Koval ◽  
D Koshland
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Dna ◽  
Live Cells ◽  
Chromosome Movement ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chromosome Separation ◽  
Higher Eukaryotes ◽  
Spindle Position ◽  
Rate Of Movement

Nuclear DNA movement in the yeast, Saccharomyces cerevisiae, was analyzed in live cells using digital imaging microscopy and corroborated by the analysis of nuclear DNA position in fixed cells. During anaphase, the replicated nuclear genomes initially separated at a rate of 1 micron/min. As the genomes separated, the rate of movement became discontinuous. In addition, the axis defined by the segregating genomes rotated relative to the cell surface. The similarity between these results and those previously obtained in higher eukaryotes suggest that the mechanism of anaphase movement may be highly conserved. Before chromosome separation, novel nuclear DNA movements were observed in cdc13, cdc16, and cdc23 cells but not in wild-type or cdc20 cells. These novel nuclear DNA movements correlated with variability in spindle position and length in cdc16 cells. Models for the mechanism of these movements and their induction by certain cdc mutants are discussed.

scholarly journals Effect of Yeast (saccharomyces cerevisiae) Supplementation on Haematological Parameters in Surti Buffalo Calves

2018 ◽  
Vol 14 (1) ◽  
Author(s):  
Virendra Kumar Singh ◽  
Sandhya S. Chaudhary ◽  
Tanvi D. Manat ◽  
Rana Ranjeet Singh ◽  
Kuldeep Tyagi ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dietary Supplementation ◽  
Young Female ◽  
Haematological Parameters ◽  
Haematological Parameter ◽  
Buffalo Calves ◽  
Yeast Saccharomyces Cerevisiae ◽  
Group I ◽  
Inclusion Rate ◽  
Surti Buffalo

The present study was conducted to evaluate the effect of dietary supplementation of yeast (Saccharomyces cerevisiae) on haematological parameter in 21 Surti young female buffalo calves (aged 6-12 months). They were divided equally into 3 groups (7 calves in each group) viz. Group I (control), II (supplementation of rumen specific yeast Saccharomyces cerevisiae CNCM I-1077 @ 4x109 cfu/animal/day) and III (supplementation of product of inactivated whole cell yeast Saccharomyces cerevisiae containing elevated levels of L (+) selenomethionine @ selenium inclusion rate in feed at 0.3 ppm). Whole blood was collected at day 0, 45 and 90 and haematological parameters were studied. Except in Group II which showed significant decrease in TEC, all haematological parameters were found within normal physiological range. Thus it was concluded that in female Surti buffalo calves supplementation of yeast and selenized yeast did not cause any significant change in haematological parameters.

scholarly journals Pre-mRNA topology is important for 3'-end formation in Saccharomyces cerevisiae and mammals.

1996 ◽  
Vol 16 (5) ◽  
pp. 2204-2213 ◽  
Author(s):  
G Stumpf ◽  
A Goppelt ◽  
H Domdey
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Extract ◽  
Cell Extract ◽  
Circular Rnas ◽  
Yeast Saccharomyces Cerevisiae ◽  
General Importance ◽  
Higher Eukaryotes ◽  
Whole Cell Extract ◽  
Cell Nuclear Extract

Various signal motifs that are required for efficient pre-mRNA 3'-end formation in the yeast Saccharomyces cerevisiae have been reported. None of these known signal sequences appears to be of the same general importance as is the mammalian AAUAAA motif. To establish the importance of yeast pre-mRNA termini in 3'-end formation, the ends of a pre-mRNA transcript synthesized in vitro were ligated before incubation in a yeast whole-cell extract. Such covalently closed circular RNAs were not cleaved at their poly(A) sites. Interestingly, pseudocircular RNAs with complementary 3'- and 5'-terminal sequences allowing the formation of panhandle structures were also resistant to cleavage. However, 3'-end processing was impeded neither by terminal hairpins at either or at both ends nor by RNA oligonucleotides complementary to either or both ends of a linear pre-mRNA. Intriguingly mammalian pseudocircular pre-mRNAs also were not cleaved at their poly(A) sites when incubated in a HeLa cell nuclear extract. These results provide evidence for the general importance of RNA topology in the formation of an active 3'-end processing complex in S. cerevisiae and higher eukaryotes. The possibility of a torus-shaped factor involved in 3'-end formation is discussed.

Sign in / Sign up

Export Citation Format

Share Document