Iron drives anabolic metabolism through active histone demethylation and mTORC1.

All eukaryotic cells require a minimal iron threshold to sustain anabolic metabolism. However, the mechanisms by which cells sense iron to regulate anabolic processes are unclear. Here we report a previously undescribed eukaryotic pathway for iron sensing in which molecular iron is required to sustain active histone demethylation and maintain the expression of critical components of the pro-anabolic mTORC1 pathway.

Maintaining transcriptional homeostasis during cell cycle.

The preservation of gene expression patterns that define cellular identity throughout the cell division cycle is essential to perpetuate cellular lineages. However, the progression of cells through different phases of the cell cycle severely disrupts chromatin accessibility, epigenetic marks, and the recruitment of transcriptional regulators. Notably, chromatin is transiently disassembled during S-phase and undergoes drastic condensation during mitosis, which is a significant challenge to the preservation of gene expression patterns between cell generations.

Analysis of the pheromone signaling pathway by RT-qPCR in the budding yeast .

and expression levels can be used as reporters for signaling through the pheromone pathway in the budding yeast . Here, we describe an optimized protocol to measure the expression levels of and using quantitative reverse transcription PCR (RT-qPCR). We describe the steps for comparing untreated and pheromone-treated yeast cells and how to quantify the changes in various deletion strains.

Waves of sumoylation support transcription dynamics during adipocyte differentiation.

Tight control of gene expression networks required for adipose tissue formation and plasticity is essential for adaptation to energy needs and environmental cues. However, the mechanisms that orchestrate the global and dramatic transcriptional changes leading to adipocyte differentiation remain to be fully unraveled. We investigated the regulation of nascent transcription by the sumoylation pathway during adipocyte differentiation using SLAMseq and ChIPseq.

Kel1 is a phosphorylation-regulated noise suppressor of the pheromone signaling pathway.

Mechanisms have evolved that allow cells to detect signals and generate an appropriate response. The accuracy of these responses relies on the ability of cells to discriminate between signal and noise. How cells filter noise in signaling pathways is not well understood.

Iron Regulatory Mechanisms in .

Iron is an essential micronutrient for all eukaryotic organisms because it participates as a redox cofactor in many cellular processes. However, excess iron can damage cells since it promotes the generation of reactive oxygen species. The budding yeast has been used as a model organism to study the adaptation of eukaryotic cells to changes in iron availability.

The yeast Aft1 transcription factor activates ribonucleotide reductase catalytic subunit RNR1 in response to iron deficiency.

Eukaryotic ribonucleotide reductases are iron-dependent enzymes that catalyze the rate-limiting step in the de novo synthesis of deoxyribonucleotides. Multiple mechanisms regulate the activity of ribonucleotide reductases in response to genotoxic stresses and iron deficiency. Upon iron starvation, the Saccharomyces cerevisiae Aft1 transcription factor specifically binds to iron-responsive cis elements within the promoter of a group of genes, known as the iron regulon, activating their transcription.

Global translational repression induced by iron deficiency in yeast depends on the Gcn2/eIF2α pathway.

Iron is an essential element for all eukaryotic organisms because it participates as a redox active cofactor in a wide range of biological processes, including protein synthesis. Translation is probably the most energy consuming process in cells. Therefore, one of the initial responses of eukaryotic cells to stress or nutrient limitation is the arrest of mRNA translation.

A genome-wide transcriptional study reveals that iron deficiency inhibits the yeast TORC1 pathway.

Iron is an essential micronutrient that participates as a cofactor in a broad range of metabolic processes including mitochondrial respiration, DNA replication, protein translation and lipid biosynthesis. Adaptation to iron deficiency requires the global reorganization of cellular metabolism directed to optimize iron utilization. The budding yeast Saccharomyces cerevisiae has been widely used to characterize the responses of eukaryotic microorganisms to iron depletion.

Molecular strategies to increase yeast iron accumulation and resistance.

All eukaryotic organisms rely on iron as an essential micronutrient for life because it participates as a redox-active cofactor in multiple biological processes. However, excess iron can generate reactive oxygen species that damage cellular macromolecules. The low solubility of ferric iron under physiological conditions increases the prevalence of iron deficiency anemia.

Dissecting mRNA decay and translation inhibition during iron deficiency.

Iron participates as a vital cofactor in multiple metabolic pathways. Despite its abundance, iron bioavailability is highly restricted in aerobic and alkaline environments. Therefore, living organisms have evolved multiple adaptive mechanisms to respond to iron scarcity.

mRNA-binding protein tristetraprolin is essential for cardiac response to iron deficiency by regulating mitochondrial function.

Cells respond to iron deficiency by activating iron-regulatory proteins to increase cellular iron uptake and availability. However, it is not clear how cells adapt to conditions when cellular iron uptake does not fully match iron demand. Here, we show that the mRNA-binding protein tristetraprolin (TTP) is induced by iron deficiency and degrades mRNAs of mitochondrial Fe/S-cluster-containing proteins, specifically in complex I and in complex III, to match the decrease in Fe/S-cluster availability.

Yeast Cth2 protein represses the translation of ARE-containing mRNAs in response to iron deficiency.

In response to iron deficiency, the budding yeast Saccharomyces cerevisiae undergoes a metabolic remodeling in order to optimize iron utilization. The tandem zinc finger (TZF)-containing protein Cth2 plays a critical role in this adaptation by binding and promoting the degradation of multiple mRNAs that contain AU-rich elements (AREs). Here, we demonstrate that Cth2 also functions as a translational repressor of its target mRNAs.

The elemental role of iron in DNA synthesis and repair.

Iron is an essential redox element that functions as a cofactor in many metabolic pathways. Critical enzymes in DNA metabolism, including multiple DNA repair enzymes (helicases, nucleases, glycosylases, demethylases) and ribonucleotide reductase, use iron as an indispensable cofactor to function. Recent striking results have revealed that the catalytic subunit of DNA polymerases also contains conserved cysteine-rich motifs that bind iron-sulfur (Fe/S) clusters that are essential for the formation of stable and active complexes.

Correlation between Low Temperature Adaptation and Oxidative Stress in Saccharomyces cerevisiae.

Many factors, such as must composition, juice clarification, fermentation temperature, or inoculated yeast strain, strongly affect the alcoholic fermentation and aromatic profile of wine. As fermentation temperature is effectively controlled by the wine industry, low-temperature fermentation (10-15°C) is becoming more prevalent in order to produce white and "rosé" wines with more pronounced aromatic profiles. Elucidating the response to cold in Saccharomyces cerevisiae is of paramount importance for the selection or genetic improvement of wine strains.

Genome-wide identification of genes involved in growth and fermentation activity at low temperature in Saccharomyces cerevisiae.

Fermentation at low temperatures is one of the most popular current winemaking practices because of its reported positive impact on the aromatic profile of wines. However, low temperature is an additional hurdle to develop Saccharomyces cerevisiae wine yeasts, which are already stressed by high osmotic pressure, low pH and poor availability of nitrogen sources in grape must. Understanding the mechanisms of adaptation of S.