scholarly journals Enzymes of yeast polyphosphate metabolism: structure, enzymology and biological roles

2016 ◽  
Vol 44 (1) ◽  
pp. 234-239 ◽  
Author(s):  
Rūta Gerasimaitė ◽  
Andreas Mayer

Inorganic polyphosphate (polyP) is found in all living organisms. The known polyP functions in eukaryotes range from osmoregulation and virulence in parasitic protozoa to modulating blood coagulation, inflammation, bone mineralization and cellular signalling in mammals. However mechanisms of regulation and even the identity of involved proteins in many cases remain obscure. Most of the insights obtained so far stem from studies in the yeast Saccharomyces cerevisiae. Here, we provide a short overview of the properties and functions of known yeast polyP metabolism enzymes and discuss future directions for polyP research.

2019 ◽  
Vol 20 (9) ◽  
pp. 2133 ◽  
Author(s):  
Antonella Locascio ◽  
Nuria Andrés-Colás ◽  
José Miguel Mulet ◽  
Lynne Yenush

Sodium and potassium are two alkali cations abundant in the biosphere. Potassium is essential for plants and its concentration must be maintained at approximately 150 mM in the plant cell cytoplasm including under circumstances where its concentration is much lower in soil. On the other hand, sodium must be extruded from the plant or accumulated either in the vacuole or in specific plant structures. Maintaining a high intracellular K+/Na+ ratio under adverse environmental conditions or in the presence of salt is essential to maintain cellular homeostasis and to avoid toxicity. The baker’s yeast, Saccharomyces cerevisiae, has been used to identify and characterize participants in potassium and sodium homeostasis in plants for many years. Its utility resides in the fact that the electric gradient across the membrane and the vacuoles is similar to plants. Most plant proteins can be expressed in yeast and are functional in this unicellular model system, which allows for productive structure-function studies for ion transporting proteins. Moreover, yeast can also be used as a high-throughput platform for the identification of genes that confer stress tolerance and for the study of protein–protein interactions. In this review, we summarize advances regarding potassium and sodium transport that have been discovered using the yeast model system, the state-of-the-art of the available techniques and the future directions and opportunities in this field.


2021 ◽  
Author(s):  
Benoît REVEL ◽  
Patrice CATTY ◽  
Stéphane RAVANEL ◽  
Jacques BOURGUIGNON ◽  
Claude ALBAN

Uranium (U) is a naturally-occurring radionuclide toxic for living organisms that can take it up. To date, the mechanisms of U uptake are far from being understood. Here, we used the yeast Saccharomyces cerevisiae as a unicellular eukaryote model to identify U assimilation pathways. Thus, we have identified, for the first time, transport machineries capable of transporting U in a living organism. First, we evidenced a metabolism-dependent U transport in yeast. Then, competition experiments with essential metals allowed us to identify calcium, iron and copper entry pathways as potential routes for U uptake. The analysis of various metal transport mutants revealed that mid1Δ, cch1Δ and ftr1Δ mutants, affected in calcium (Mid1/Cch1 channel) and Fe(III) (Ftr1/Fet3 complex) transport, respectively, exhibited highly reduced U uptake rates and accumulation, demonstrating the implication of these import systems in U uptake. Finally, expression of the Mid1 gene into the mid1Δ mutant restored U uptake levels of the wild type strain, underscoring the central role of the Mid1/Cch1 calcium channel in U absorption process in yeast. Our results also open up the opportunity for rapid screening of U-transporter candidates by functional expression in yeast, before their validation in more complex higher eukaryote model systems.


2000 ◽  
Vol 11 (12) ◽  
pp. 4309-4321 ◽  
Author(s):  
Nobuo Ogawa ◽  
Joseph DeRisi ◽  
Patrick O. Brown

The PHO regulatory pathway is involved in the acquisition of phosphate (Pi) in the yeast Saccharomyces cerevisiae. When extracellular Piconcentrations are low, several genes are transcriptionally induced by this pathway, which includes the Pho4 transcriptional activator, the Pho80-Pho85 cyclin-CDK pair, and the Pho81 CDK inhibitor. In an attempt to identify all the components regulated by this system, a whole-genome DNA microarray analysis was employed, and 22 PHO-regulated genes were identified. The promoter regions of 21 of these genes contained at least one copy of a sequence that matched the Pho4 recognition site. Eight of these genes, PHM1–PHM8, had no previously defined function in phosphate metabolism. The amino acid sequences ofPHM1 (YFL004w), PHM2 (YPL019c),PHM3 (YJL012c), and PHM4 (YER072w) are 32–56% identical. The phm3 and phm4single mutants and the phm1 phm2 double mutant were each severely deficient in accumulation of inorganic polyphosphate (polyP) and Pi. The phenotype of thephm5 mutant suggests that PHM5 (YDR452w)is essential for normal catabolism of polyP in the yeast vacuole. Taken together, the results reveal important new features of a genetic system that plays a critical role in Piacquisition and polyP metabolism in yeast.


2021 ◽  
Vol 7 (8) ◽  
pp. 626
Author(s):  
Marina Pascual-Ortiz ◽  
Eva Walla ◽  
Ursula Fleig ◽  
Adolfo Saiardi

Inorganic polyphosphate (polyP) which is ubiquitously present in both prokaryotic and eukaryotic cells, consists of up to hundreds of orthophosphate residues linked by phosphoanhydride bonds. The biological role of this polymer is manifold and diverse and in fungi ranges from cell cycle control, phosphate homeostasis and virulence to post-translational protein modification. Control of polyP metabolism has been studied extensively in the budding yeast Saccharomyces cerevisiae. In this yeast, a specific class of inositol pyrophosphates (IPPs), named IP7, made by the IP6K family member Kcs1 regulate polyP synthesis by associating with the SPX domains of the vacuolar transporter chaperone (VTC) complex. To assess if this type of regulation was evolutionarily conserved, we determined the elements regulating polyP generation in the distantly related fission yeast Schizosaccharomyces pombe. Here, the VTC machinery is also essential for polyP generation. However, and in contrast to S. cerevisiae, a different IPP class generated by the bifunctional PPIP5K family member Asp1 control polyP metabolism. The analysis of Asp1 variant S. pombe strains revealed that cellular polyP levels directly correlate with Asp1-made IP8 levels, demonstrating a dose-dependent regulation. Thus, while the mechanism of polyP synthesis in yeasts is conserved, the IPP player regulating polyP metabolism is diverse.


2020 ◽  
Vol 115 (11) ◽  
pp. 413-417
Author(s):  
Patrizia Janković ◽  
Renos Spinosi ◽  
Anna Bacardit

With many industries discharging heavy metals into natural water resources, heavy metals have been found to accumulate in various living organisms which can ultimately threaten human life and pose a big threat to the environment. Thus, in the pursuit of a solution to the above mentioned problem, bioaccumulation has emerged as an interesting option for the removal of heavy metals from wastewater. In this paper, the effectiveness of the yeast Saccharomyces cerevisiae in the bioaccumulation of Cr3+ has been tested. Also, different factors influencing Cr3+ uptake have been discussed.  This work has demonstrated that Saccharomyces cerevisiae is an effective Cr3+ biosorbent for tannery wastewater. The conditions of use of this yeast to achieve optimal chromium (III) absorption are: i) when a growth of the biosorbent equivalent to a similar concentration of Cr3+ is obtained, which contains the residual water that needs to be treated; ii) the smaller the biosorbent is the better the biosorption; iii) the uptake of Cr3+ is more efficient when no extra growth medium is added to the wastewater; iv) the longer the exposure period of the yeast to Cr3+ , the bigger the Cr3+ reduction. Since Saccharomyces cerevisiae is an inexpensive, readily available source of biomass, this discovery could be of great use for a low-budget and efficient wastewater treatment system


2016 ◽  
Vol 13 (1) ◽  
pp. 93
Author(s):  
Titin Yulinery ◽  
Ratih M.Dewi

Tes kemampuan adalah salah satu kegiatan penting dalam pengendalian mutu dan jaminan kualitas mikrobiologi laboratorium untuk mengukur kompetensi analis dan analisis uji profisiensi membutuhkan persiapan Model mikroorganisme adalah kualitas standar dan validitas. Mikrobiologi uji kualitas produk kedelai utama diarahkan pada kehadiran Saccharomyces cerevisiae ragi (S. cerevisiae), S. Bailli, S. rouxii dankontaminan bakteri seperti Bacillus dan Deinococcus. Jenis ragi dan bakteri yang terlibat dalam proses dan dapat menjadi salah satu parameter kualitas penting dalam persiapan yang dihasilkan. Jumlah dan viabilitas bakteri dan ragi menjadi parameter utama dalam proses persiapan bahan uji. Jumlah tersebut adalah jumlah minimum yang berlaku dapat dianalisis. Jumlah ini harus dibawah 10 CFU diperlukan untuk menunjukkan tingkat hygienitas proses dan tingkat minimal kontaminasi. Viabilitas bakteri dan bahan tes ragi persiapan untuk tes kemahiran kecap yang diawetkan dengan L-pengeringan adalah teknik Deinococcus radiodurans (D. radiodurans) 16 tahun, 58 tahun S. cerevisiae, dan S. roxii 13 tahun. kata kunci: Viabilitas, Deinococcus, khamir, L-pengeringan, Proficiency AbstractProficiency test is one of the important activities in quality control and quality assurance microbiology laboratory for measuring the competence of analysts and analysis Proficiency test requires a model microorganism preparations are standardized quality and validity. Microbiological test of the quality of the main soy products aimed at thepresence of yeast Saccharomyces cerevisiae (S. cerevisiae), S. bailli, S. rouxii and bacterial contaminants such as Bacillus and Deinococcus. Types of yeasts and bacteria involved in the process and can be one of the important quality parameters in the preparation produced. The number and viability of bacteria and yeasts become themain parameters in the process of test preparation materials. The amount in question is the minimum number that is valid can be analyzed. This amount must be below 10 CFU required to indicate the level of hygienitas process and the minimum level of contamination. Viability of bacteria and yeast test preparation materials for proficiencytest of soy sauce that preserved by L-drying technique is Deinococcus radiodurans ( D. radiodurans ) 16 years, 58 years S. cerevisiae, and S. roxii 13 years. key words : Viability, Deinococcus, Khamir, L-drying, Proficiency


Tsitologiya ◽  
2018 ◽  
Vol 60 (7) ◽  
pp. 555-557 ◽  
Author(s):  
E. A. Alekseeva ◽  
◽  
T. A. Evstyukhina ◽  
V. T. Peshekhonov ◽  
V. G. Korolev ◽  
...  

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