Isolation and characterization of a cDNA encoding a Δ8 sphingolipid desaturase from Aquilegia vulgaris

2002 ◽  
Vol 30 (6) ◽  
pp. 1073-1075 ◽  
Author(s):  
L. V. Michaelson ◽  
A. J. Longman ◽  
O. Sayanova ◽  
A. K. Stobart ◽  
J. A. Napier
Keyword(s):  
Functional Characterization ◽  
Yeast Cells ◽  
Sphingoid Bases ◽  
Yeast Saccharomyces Cerevisiae ◽  
Isolation And Characterization ◽  
Long Chain Base ◽  
In The Wild ◽  
Cis And Trans ◽  
Long Chain

We have isolated a cDNA encoding the Δ8 sphingolipid desaturase from the plant Aquilegia vulgaris L. via a PCR-based strategy using primers designed to target the conserved histidine box regions of microsomal desaturases. The function of the cDNA was confirmed by expression in the yeast, Saccharomyces cerevisiae. Analysis of the long-chain sphingoid bases as their dinitrophenyl derivatives by reverse-phase HPLC demonstrated the accumulation of cis- and trans-desaturated sphingoid bases which were not present in the wild-type yeast cells. The Δ8 desaturated products co-eluted with known Δ8-desaturated phytosphingenine and the molecular mass of these products was confirmed by liquid chromatography-MS. The Δ8 long-chain base desaturase was also able to desaturate dihydrosphingosine substrates. This is the first report of the functional characterization of an A. vulgaris gene product.

Isolation of mutant Saccharomyces cerevisiae strains that survive without sphingolipids

1990 ◽  
Vol 10 (5) ◽  
pp. 2176-2181
Author(s):  
R C Dickson ◽  
G B Wells ◽  
A Schmidt ◽  
R L Lester
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Membrane Lipids ◽  
Molecular Genetic ◽  
Suppressor Gene ◽  
Molecular Genetic Analysis ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chain Base ◽  
Long Chain Base ◽  
Long Chain

Sphingolipids comprise a large, widespread family of complex eucaryotic-membrane constituents of poorly defined function. The yeast Saccharomyces cerevisiae is particularly suited for studies of sphingolipid function because it contains a small number of sphingolipids and is amenable to molecular genetic analysis. Moreover, it is the only eucaryote in which mutants blocked in sphingolipid biosynthesis have been isolated. Beginning with a nonreverting sphingolipid-defective strain that requires the addition of the long-chain-base component of sphingolipids to the culture medium for growth, we isolated two strains carrying secondary, suppressor mutations that permit survival in the absence of exogenous long-chain base. Remarkably, the suppressor strains made little if any sphingolipid. A study of how the suppressor gene products compensate for the lack of sphingolipids may reveal the function(s) of these membrane lipids in yeast cells.

scholarly journals Isolation of mutant Saccharomyces cerevisiae strains that survive without sphingolipids.

1990 ◽  
Vol 10 (5) ◽  
pp. 2176-2181 ◽  
Author(s):  
R C Dickson ◽  
G B Wells ◽  
A Schmidt ◽  
R L Lester
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Membrane Lipids ◽  
Molecular Genetic ◽  
Suppressor Gene ◽  
Molecular Genetic Analysis ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chain Base ◽  
Long Chain Base ◽  
Long Chain

Sphingolipids comprise a large, widespread family of complex eucaryotic-membrane constituents of poorly defined function. The yeast Saccharomyces cerevisiae is particularly suited for studies of sphingolipid function because it contains a small number of sphingolipids and is amenable to molecular genetic analysis. Moreover, it is the only eucaryote in which mutants blocked in sphingolipid biosynthesis have been isolated. Beginning with a nonreverting sphingolipid-defective strain that requires the addition of the long-chain-base component of sphingolipids to the culture medium for growth, we isolated two strains carrying secondary, suppressor mutations that permit survival in the absence of exogenous long-chain base. Remarkably, the suppressor strains made little if any sphingolipid. A study of how the suppressor gene products compensate for the lack of sphingolipids may reveal the function(s) of these membrane lipids in yeast cells.

Degradation of long-chain base 1-phosphate (LCBP) in Arabidopsis: functional characterization of LCBP phosphatase involved in the dehydration stress response

2011 ◽  
Vol 125 (3) ◽  
pp. 439-449 ◽  
Author(s):  
Noriko Nakagawa ◽  
Mai Kato ◽  
Yohei Takahashi ◽  
Ken-ichiro Shimazaki ◽  
Kentarao Tamura ◽  
...  
Keyword(s):  
Stress Response ◽  
Functional Characterization ◽  
Dehydration Stress ◽  
Chain Base ◽  
Long Chain Base ◽  
Long Chain

scholarly journals Induction of the synthesis of an additional family of long-chain dolichols in the yeast Saccharomyces cerevisiae. Effect of starvation and ageing.

2002 ◽  
Vol 49 (3) ◽  
pp. 781-787 ◽  
Author(s):  
Anna Szkopinska ◽  
Ewa Swiezewska ◽  
Joanna Rytka
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stationary Phase ◽  
Yeast Cells ◽  
Logarithmic Phase ◽  
Cellular Membranes ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chemical Changes ◽  
Physico Chemical ◽  
Long Chain

The yeast Saccharomyces cerevisiae strain W303 synthesizes in the early logarithmic phase of growth dolichols of 14-18 isoprene residues. The analysis of the polyisoprenoids present in the stationary phase revealed an additional family which proved to be also dolichols but of 19-24 isoprene residues, constituting 39% of the total dolichols. The transfer of early logarithmic phase cells to a starvation medium lacking glucose or nitrogen resulted in the synthesis of the longer chain dolichols. The additional family of dolichols represented 13.8% and 10.3% of total dolichols in the glucose and nitrogen deficient media, respectively. The level of dolichols in yeast cells increased with the age of the cultures. Since both families of dolichols are present in stationary phase cells we postulate that the longer chain dolichols may be responsible for the physico-chemical changes in cellular membranes allowing yeast cells to adapt to nutrient deficient conditions to maintain long-term viability.

scholarly journals Isolation and Characterization of Mutations in theEscherichia coli Regulatory Protein XapR

1999 ◽  
Vol 181 (14) ◽  
pp. 4397-4403 ◽  
Author(s):  
Casper Jørgensen ◽  
Gert Dandanell
Keyword(s):  
Amino Acids ◽  
Purine Nucleoside Phosphorylase ◽  
Mutational Analysis ◽  
Regulatory Protein ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Wild Type ◽  
Isolation And Characterization ◽  
In The Wild

ABSTRACT In this work, the LysR-type protein XapR has been subjected to a mutational analysis. XapR regulates the expression of xanthosine phosphorylase (XapA), a purine nucleoside phosphorylase inEscherichia coli. In the wild type, full expression of XapA requires both a functional XapR protein and the inducer xanthosine. Here we show that deoxyinosine can also function as an inducer in the wild type, although not to the same extent as xanthosine. We have isolated and characterized in detail the mutants that can be induced by other nucleosides as well as xanthosine. Sequencing of the mutants has revealed that two regions in XapR are important for correct interactions between the inducer and XapR. One region is defined by amino acids 104 and 132, and the other region, containing most of the isolated mutations, is found between amino acids 203 and 210. These regions, when modelled into the three-dimensional structure of CysB from Klebsiella aerogenes, are placed close together and are most probably directly involved in binding the inducer xanthosine.

scholarly journals Functional and Genomic Characterization of Ligilactobacillus salivarius TUCO-L2 Isolated From Lama glama Milk: A Promising Immunobiotic Strain to Combat Infections

2020 ◽  
Vol 11 ◽  
Author(s):  
Sandra Quilodrán-Vega ◽  
Leonardo Albarracin ◽  
Flavia Mansilla ◽  
Lorena Arce ◽  
Binghui Zhou ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Functional Characterization ◽  
Comparative Genomic ◽  
Cytokines And Chemokines ◽  
Isolation And Characterization ◽  
Intestinal Pathogens ◽  
Lama Glama

Potential probiotic or immunobiotic effects of lactic acid bacteria (LAB) isolated from the milk of the South American camelid llama (Lama glama) have not been reported in published studies. The aim of the present work was to isolate beneficial LAB from llama milk that can be used as potential probiotics active against bacterial pathogens. LAB strains were isolated from llama milk samples. In vitro functional characterization of the strains was performed by evaluating the resistance against gastrointestinal conditions and inhibition of the pathogen growth. Additionally, the adhesive and immunomodulatory properties of the strains were assessed. The functional studies were complemented with a comparative genomic evaluation and in vivo studies in mice. Ligilactobacillus salivarius TUCO-L2 showed enhanced probiotic/immunobiotic potential compared to that of other tested strains. The TUCO-L2 strain was resistant to pH and high bile salt concentrations and demonstrated antimicrobial activity against Gram-negative intestinal pathogens and adhesion to mucins and epithelial cells. L. salivarius TUCO-L2 modulated the innate immune response triggered by Toll-like receptor (TLR)-4 activation in intestinal epithelial cells. This effect involved differential regulation of the expression of inflammatory cytokines and chemokines mediated by the modulation of the negative regulators of the TLR signaling pathway. Moreover, the TUCO-L2 strain enhanced the resistance of mice to Salmonella infection. This is the first report on the isolation and characterization of a potential probiotic/immunobiotic strain from llama milk. The in vitro, in vivo, and in silico investigation performed in this study reveals several research directions that are needed to characterize the TUCO-L2 strain in detail to position this strain as a probiotic or immunobiotic that can be used against infections in humans or animals, including llama.

Isolation and characterization of Ts19 Fragment II, a new long-chain potassium channel toxin from Tityus serrulatus venom

Peptides ◽  
2016 ◽  
Vol 80 ◽  
pp. 9-17 ◽  
Author(s):  
Felipe Augusto Cerni ◽  
Manuela Berto Pucca ◽  
Fernanda Gobbi Amorim ◽  
Karla de Castro Figueiredo Bordon ◽  
Julien Echterbille ◽  
...  
Keyword(s):  
Potassium Channel ◽  
Isolation And Characterization ◽  
Tityus Serrulatus ◽  
Tityus Serrulatus Venom ◽  
Long Chain
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