S. pombe

Telomeric repeat-binding factor 1 (Tbf1) has a similar architecture as the TRF family of telomeric proteins and plays important roles in both telomere homeostasis and ribosome regulation. However, the molecular basis of why Tbf1 has such different functions compared to other TRFs remains unclear. Here, we present the crystal structures of the TRF homology (TRFH) and Myb-L domains from Schizosaccharomyces pombe Tbf1 (spTbf1). TRFH-mediated homodimerization is essential for spTbf1 stability. Importantly, spTbf1TRFH lacks the conserved docking motif for interactions with telomeric proteins, explaining why spTbf1 does not participate in the assembly of the shelterin complex...

(1) Background: The identification of microorganisms includes traditional biochemical methods, molecular biology methods evaluating the conserved regions of rRNA, and the molecular biology of proteins (proteomics), such as MALDI-TOF MS mass spectrometry. This work aimed to identify the biodiversity of yeasts associated with stingless bee species' honey and pollen, Melipona scutellaris , Nannotrigona testaceicornes , and Tetragonisca angustula , from the region of São Gonçalo dos Campos-Bahia (BA) state, Brazil...

Pre-mRNA splicing plays a key role in the regulation of gene expression. Recent discoveries suggest that defects in pre-mRNA splicing, resulting from the dysfunction of certain splicing factors, can impact the expression of genes crucial for genome surveillance mechanisms, including those involved in cellular response to DNA damage. In this study, we analyzed how cells with a non-functional spliceosome-associated Gpl1-Gih35-Wdr83 complex respond to DNA damage. Additionally, we investigated the role of this complex in regulating the splicing of factors involved in DNA damage repair...

Schizosaccharomyces pombe is a commonly utilized model organism for studying various aspects of eukaryotic cell physiology. One reason for its widespread use as an experimental system is the ease of genetic manipulations, leveraging the natural homology-targeted repair mechanism to accurately modify the genome. We conducted a study to assess the feasibility and efficiency of directly introducing exogenous genes into the fission yeast S. pombe using Polymerase Chain Reaction (PCR) with short-homology flanking sequences...

KAT5 (S. pombe Mst1, human TIP60) is a MYST family histone acetyltransferase conserved from yeast to humans that is involved in multiple cellular activities. This family is characterized in part by containing a chromodomain, a motif associated with binding methylated histones. We show that a chromodomain mutation in the S. pombe Kat5, mst1-W66R, has defects in pericentromere silencing. mst1-W66R is sensitive to camptothecin (CPT) but only at an increased temperature of 36°C, although it is proficient for growth at this temperature...

UNLABELLED: Due to fungal diseases that threaten immunocompromised patients, along with the limited availability of antifungal agents, there is an urgent need for new antifungal compounds to treat fungal infections. Here, we aimed to identify potential antifungal drugs from natural products using the fission yeast Schizosaccharomyces pombe as a model organism since it shares many features with some pathogenic fungi. Here, we identified tubeimoside I (TBMS1), an extract from Chinese herbal medicine, that showed strong antifungal activity against S...

Glycosyl-phosphatidylinositol (GPI) anchored proteins are implicated in remodeling of the yeast cell wall during growth and division. Schizosaccharomyces pombe proteins, Psu1 , Dfg501 , and Dfg502 are predicted GPI anchored proteins with likely cell wall modifying activity. Here, we isolated and characterized null and temperature-sensitive alleles that will allow further analysis of the function of these proteins and S. pombe cell wall formation. Our data confirm that Psu1 is necessary for cell separation, maintaining proper cell shape, and viability...

Phosphatidylserine (PS) is important for maintaining growth, cytoskeleton, and various functions in yeast; however, its role in stress responses is poorly understood. In Schizosaccharomyces pombe, the PS synthase deletion (pps1∆) mutant shows defects in growth, morphology, cytokinesis, actin cytoskeleton, and cell wall integrity, and these phenotypes are rescued by ethanolamine supplementation. Here, we evaluated the role of Pps1 in the salt stress response in S. pombe. We found that pps1∆ cells are sensitive to salt stresses such as KCl and CaCl2 even in the presence of ethanolamine...

A critical feature of the cellular antioxidant response is the induction of gene expression by redox-sensitive transcription factors. In many cells, activating these transcription factors is a dynamic process involving multiple redox steps, but it is unclear how these dynamics should be measured. Here, we show how the dynamic profile of the Schizosaccharomyces pombe Pap1 transcription factor is quantifiable by three parameters: signal amplitude, signal time and signal duration. In response to increasing hydrogen peroxide concentrations, the Pap1 amplitude decreased while the signal time and duration showed saturable increases...

BACKGROUND: Mitogen-activated protein kinases (MAPKs) preserve cell homeostasis by transducing physicochemical fluctuations of the environment into multiple adaptive responses. These responses involve transcriptional rewiring and the regulation of cell cycle transitions, among others. However, how stress conditions impinge mitotic progression is largely unknown. The mitotic checkpoint is a surveillance mechanism that inhibits mitotic exit in situations of defective chromosome capture, thus preventing the generation of aneuploidies...

RNA polymerase II transcription elongation directs an intricate pattern of histone modifications. This pattern includes a regulatory cascade initiated by the elongation factor Rtf1, leading to monoubiquitylation of histone H2B, and subsequent methylation of histone H3 on lysine 4. Previous studies have defined the molecular basis for these regulatory relationships, but it remains unclear how they regulate gene expression. To address this question, we investigated a drug resistance phenotype that characterizes defects in this axis in the model eukaryote Schizosaccharomyces pombe (fission yeast)...

The Schizosaccharomyces pombe Gas family of β-1,3-glucanosyltransferases modify the cell wall by elongating β-1,3-glucan chains. While gas1Δ cells are inviable under standard laboratory growth conditions, they are viable in the presence of an osmotic stabilizer. Even under these conditions however, gas1Δ cells are slow-growing and display cell separation and morphology defects. Here, we isolated and characterized two gas1 temperature-sensitive alleles. Our data support that Gas1 is the primary S...

Pentatricopeptide repeat proteins are involved in mitochondrial both transcriptional and posttranscriptional regulation. Schizosaccharomyces pombe Ppr2 is a general mitochondrial translation factor that plays a critical role in the synthesis of all mitochondrial DNA-encoded oxidative phosphorylation subunits, which are essential for mitochondrial respiration. Our previous analysis showed that ppr2 deletion resulted in increased expression of iron uptake genes and caused ferroptosis-like cell death in S. pombe...

For most Eukaryotic species the requirements of cilia formation dictate the structure of microtubule organizing centers (MTOCs). In this study we find that loss of cilia corresponds to loss of evolutionary stability for fungal MTOCs. We used iterative search algorithms to identify proteins homologous to those found in saccharomyces cerevisiae, and schizosaccharomyces pombe MTOCs, and calculated site-specific rates of change for those proteins that were broadly phylogenetically distributed. Our results indicate that both the protein composition of MTOCs as well as the sequence of MTOC proteins are poorly conserved throughout the fungal kingdom...

Glucose, which plays an essential role in carbon and energy metabolism in eukaryotes, is vital in directing various energy-consuming cellular processes. In S. cerevisiae, transcription factors involved in regulating hexose transporters and their mechanisms of action under different carbon sources were revealed in detail. However, there is limited information on these processes in S. pombe. In this study, the effect of SPCC320.03 (named SpRgt1), the ortholog of ScRgt1 whose molecular mechanism is known in detail in S...

Schizosaccharomyces japonicus belongs to the single-genus class Schizosaccharomycetes, otherwise known as "fission yeasts." As part of a composite model system with its widely studied S. pombe sister species, S. japonicus has provided critical insights into the workings and the evolution of cell biological mechanisms. Furthermore, its divergent biology makes S. japonicus a valuable model organism in its own right. However, the currently available genome assembly contains gaps and has been unable to resolve centromeres and other repeat-rich chromosomal regions...

The fission yeast Schizosaccharomyces pombe is an excellent model organism to explore cellular events owing to rich tools in genetics, molecular biology, cellular biology, and biochemistry. S. pombe proliferates continuously when nutrients are abundant, but arrests in G1 phase upon depletion of nutrients such as nitrogen and glucose. When cells of opposite mating types are present, cells conjugate, fuse, undergo meiosis, and finally form four spores. This sexual differentiation process in S. pombe has been studied extensively...

Arp2/3 complex nucleates branched actin filaments for cell and organelle movements. Here we report a 2.7 Å resolution cryo-EM structure of the mature branch junction formed by S. pombe Arp2/3 complex that provides details about interactions with both mother and daughter filaments. We determine a second structure at 3.2 Å resolution with the phosphate analog BeFx bound with ADP to Arp3 and ATP bound to Arp2. In this ADP-BeFx transition state the outer domain of Arp3 is rotated 2° toward the mother filament compared with the ADP state and makes slightly broader contacts with actin in both the mother and daughter filaments...

The ura4 gene of the fission yeast Schizosaccharomyces pombe supports both positive and negative selection; consequently, this gene is widely employed as a powerful tool to study diverse biological processes. Here we report the DNA sequences of two functionally null alleles, ura4-595 and ura4-294 . The ura4-595 allele has a four bp duplication of bp +63 to +66 (5'-CAAG-3') within the ORF and the ura4-294 allele has a nonsynonymous substitution (G to A) at bp +679. We infer that these alleles arose, respectively, by DNA polymerase template slipping and by nucleotide misincorporation (likely via cytosine deamination)...

Effects not related with the inhibition of complex I of the mitochondrial electron transport chain are studied in S. pombe, which lacks it. This study aims: First, the use of a strategy with S. pombe strains to investigate the toxicity, mechanisms of action, interactions and detoxication by efflux pumps. Second, to investigate the mechanisms of toxic action of rotenone. In the dose-response assessment, the yeast presented a good correlation with the toxicity in Daphnia magna for 15 chemicals. In the mechanistic study, the mph1Δ strain presented marked specificity to the interaction with microtubules by carbendazim...