Publications by authors named "Barbara Sivakova"

Protein phosphorylation is a dynamic, reversible posttranslational modification that plays an important role in the regulation of cell signaling. Recently, label-free quantitative (LFQ) phosphoproteomics has become a powerful tool to analyze the phosphorylation of proteins within complex samples. In this chapter, we describe how to apply LFQ phosphoproteomics that is based on Fe-IMAC phosphopeptide enrichment followed by strong anion exchange (SAX) and porous graphitic carbon (PGC) fractionation strategies for identification and quantification of changes in the phosphoproteome in the fission yeast Schizosaccharomyces pombe.

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Ksg1 is an essential protein kinase of the fission yeast S. pombe that belongs to the AGC kinase family and is homologous to the mammalian PDPK1 kinase. Previous studies have shown that Ksg1 functions in the nutrient-sensing TOR signaling pathway and is involved in the phosphorylation and activation of other AGC kinases, thereby affecting various downstream targets related to metabolism, cell division, stress response, and gene expression.

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In eukaryotes, chromosomal DNA is equally distributed to daughter cells during mitosis, whereas the number of chromosomes is halved during meiosis. Despite considerable progress in understanding the molecular mechanisms that regulate mitosis, there is currently a lack of complete understanding of the molecular mechanisms regulating meiosis. Here, we took advantage of the fission yeast Schizosaccharomyces pombe, for which highly synchronous meiosis can be induced, and performed quantitative proteomics and phosphoproteomics analyses to track changes in protein expression and phosphorylation during meiotic divisions.

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Article Synopsis
  • Ribosomes are essential ribonucleoprotein complexes present in all life forms, with size variations in ribosomal RNAs (rRNAs) due to specific regions called expansion segments (ESs).
  • The study focuses on yeasts from the Magnusiomyces/Saprochaete clade, revealing they lack significant portions of rRNAs compared to typical ones found in Saccharomyces cerevisiae, particularly in the expansion segments.
  • Despite the reduced size of rRNAs, the overall composition of ribosomal proteins remains largely unchanged, and similar reductions in rRNA size are observed across other lineages in the Saccharomycotina subphylum.
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Galactan polymer is a prominent component of the mycobacterial cell wall core. Its biogenesis starts at the cytoplasmic side of the plasma membrane by a build-up of the linker disaccharide [rhamnosyl (Rha) - N-acetyl-glucosaminyl (GlcNAc) phosphate] on the decaprenyl-phosphate carrier. This decaprenyl-P-P-GlcNAc-Rha intermediate is extended by two bifunctional galactosyl transferases, GlfT1 and GlfT2, and then it is translocated to the periplasmic space by an ABC transporter Wzm-Wzt.

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Cohesin, a multi-subunit protein complex, plays important roles in sister chromatid cohesion, DNA replication, chromatin organization, gene expression, transcription regulation, and the recombination or repair of DNA damage. Recently, several studies suggested that the functions of cohesin rely not only on cohesin-related protein-protein interactions, their post-translational modifications or specific DNA modifications, but that some RNA processing factors also play an important role in the regulation of cohesin functions. Therefore, the mutations and changes in the expression of cohesin subunits or alterations in the interactions between cohesin and RNA processing factors have been shown to have an impact on cohesion, the fidelity of chromosome segregation and, ultimately, on genome stability.

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Many fungal species utilize hydroxyderivatives of benzene and benzoic acid as carbon sources. The yeast Candida parapsilosis metabolizes these compounds via the 3-oxoadipate and gentisate pathways, whose components are encoded by two metabolic gene clusters. In this study, we determine the chromosome level assembly of the C.

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Acylation modifications, such as the succinylation of lysine, are post-translational modifications and a powerful means of regulating protein activity. Some acylations occur nonenzymatically, driven by an increase in the concentration of acyl group donors. Lysine succinylation has a profound effect on the corresponding site within the protein, as it dramatically changes the charge of the residue.

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Congenital disorder of glycosylation type Ig (ALG12-CDG) is a rare inherited metabolic disease caused by a defect in alpha-mannosyltransferase 8, encoded by the ALG12 gene (22q13.33). To date, only 15 patients have been diagnosed with ALG12-CDG globally.

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Pre-mRNA splicing is a key process in the regulation of gene expression. In the fission yeast , Nrl1 regulates splicing and expression of several genes and non-coding RNAs, and also suppresses the accumulation of R-loops. Here, we report analysis of interactions between Nrl1 and selected RNA-processing proteins and regulation of Nrl1 function by phosphorylation.

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The 3-oxoacyl-CoA thiolases catalyze the last step of the fatty acid β-oxidation pathway. In yeasts and plants, this pathway takes place exclusively in peroxisomes, whereas in animals it occurs in both peroxisomes and mitochondria. In contrast to baker's yeast Saccharomyces cerevisiae, yeast species from the Debaryomycetaceae family also encode a thiolase with predicted mitochondrial localization.

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The phosphorylation of proteins modulates various functions of proteins and plays an important role in the regulation of cell signaling. In recent years, label-free quantitative (LFQ) phosphoproteomics has become a powerful tool to analyze the phosphorylation of proteins within complex samples. Despite the great progress, the studies of protein phosphorylation are still limited in throughput, robustness, and reproducibility, hampering analyses that involve multiple perturbations, such as those needed to follow the dynamics of phosphoproteomes.

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Protein kinases are important enzymes involved in the regulation of various cellular processes. To function properly, each protein kinase phosphorylates only a limited number of proteins among the thousands present in the cell. This provides a rapid and dynamic regulatory mechanism that controls biological functions of the proteins.

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