The S–M checkpoint delays mitosis until DNA replication is complete; cells defective in this lose viability when inhibited. This inviability can be suppressed fission yeast by overexpression of Cid1 or the related protein Cid13. Fission contain six cid1/cid13 -like genes, whereas budding has just two, TRF4 and TRF5 . Trf4 Trf5 were recently reported to comprise an essential polymerase activity required for establishment sister chromatid cohesion. In contrast, we find that not a but instead...

Fission yeast Cid14, a component of the TRAMP (Cid14/Trf4-Air1-Mtr4 polyadenylation) complex, polyadenylates nuclear RNA and stimulates degradation by exosome for quality control. Here, we analyze patterns global gene expression in cells lacking Cid14 or Dis3/Rpr44 subunit exosome. We found that transcripts from many genes induced during meiosis, including key regulators, accumulated absence Dis3. Moreover, our data suggest additional substrates include involved heterochromatin assembly....

Polyadenylation in eukaryotes is conventionally associated with increased nuclear export, translation, and stability of mRNAs. In contrast, recent studies suggest that the Trf4 Trf5 proteins, members a widespread family noncanonical poly(A) polymerases, share an essential function Saccharomyces cerevisiae involves polyadenylation RNAs as part pathway exosome-mediated RNA turnover. Substrates for this include aberrantly modified tRNAs precursors snoRNAs rRNAs. Here we show Cid14 Trf4/5...

Abstract Sister chromatid cohesion is mediated by a conserved multiprotein complex called cohesin. The loading of cohesin onto chromosomes involves the RSC (remodels structure chromatin) chromatin remodeling complex. Here, we demonstrate that fission yeast Phi1, palmitoyl hydrolase inactive protein 1, serves to bridge interaction between and Phi1 interacts with Rad21 in Snf21, ATPase, promote chromosome identified characteristic features are human homologues Apt1 Apt2, which interact Brg1,...

AbstractThe S-M checkpoint is an intracellular signaling pathway that ensures mitosis not initiated in cells undergoing DNA replication. We identified cid1, a novel fission yeast gene, through its ability when overexpressed to confer specific resistance combination of hydroxyurea, which inhibits replication, and caffeine, overrides the checkpoint. Cid1 overexpression also partially suppressed hydroxyurea sensitivity characteristic polymerase δ mutants defective “checkpoint Rad” pathway....

Stress granules (SGs) are cytoplasmic aggregates of RNA and proteins in eukaryotic cells that rapidly induced response to environmental stress, but not seen growing under favorable conditions. SGs have been primarily studied mammalian cells. The existence the fission yeast distantly related budding was demonstrated only recently. In both species, they contain many orthologs SGs. this study, we characterized these determined their involvement assembly SGs, particular, homolog human G3BP...

Sister chromatid cohesion, which is established during the S phase of eukaryotic cell cycle and persists until onset anaphase, essential for maintenance genomic integrity. Cohesion requires multi-protein complex cohesin, as well a number accessory proteins including Pds5/BIMD/Spo76. In budding yeast Saccharomyces cerevisiae Pds5 an protein that localises to chromosomes in cohesin-dependent manner. Here we describe characterisation fission Schizosaccharomyces pombe pds5+, novel,non-essential...

P bodies are cytoplasmic RNA granules containing the Dcp1-Dcp2 decapping enzymes where mRNA decay can occur. Here, we describe characterization of in fission yeast Schizosaccharomyces pombe. Most information on property and function stems from studies distantly related budding Saccharomyces cerevisiae, Edc3 was identified as a scaffold protein required for P-body assembly. However, found that, unlike S. dispensable formation. Pdc1, novel partner enzyme, with limited similarity to plant...

ABSTRACT The replication checkpoint (or ‘S-M checkpoint’) control prevents progression into mitosis when DNA is incomplete. Caffeine has been known for some time to have the capacity override S-M in animal cells. We show here that caffeine also disrupts fission yeast Schizosaccharomyces pombe. By contrast, no comparable effects of on S. pombe damage were seen. cells arrested early S phase and then exposed lost viability rapidly as they attempted enter mitosis, which was accompanied by...

How γ-tubulin ring complex (γ-TuRC), a master template for microtubule nucleation, is spatially and temporally regulated the assembly of new arrays remains unclear. Here, we report that an evolutionarily conserved microprotein, Mozart1 (Mzt1), regulates subcellular targeting formation activity γ-TuRC at different cell cycle stages. Crystal structures protein complexes demonstrate Mzt1 promiscuously interacts with N-terminal domains multiple subunits in via intercalative binding mode....

Faithful chromosome segregation is fundamentally important for the maintenance of genome integrity and ploidy. By isolating conditional mutants defective in fission yeast Schizosaccharomyces pombe, we identified a role essential gene pfs2 dynamics. In absence functional Pfs2, chromosomal attachment to mitotic spindle was defective, with consequent missegregation. Under these circumstances, multiple intracellular foci checkpoint proteins Bub1 Mad2 were seen, deletion bub1 exacerbated defects...

Stress granules (SGs) are cytoplasmic aggregates formed upon stress when untranslated messenger ribonucleoproteins accumulate in the cells. In a green fluorescent protein library screening of fission yeast SG proteins, Puf2 PUF family RNA-binding proteins was identified that is required for formation after deprivation glucose. Accordingly, puf2 mutant defective recovery from glucose starvation with much longer lag to reenter cell cycle. keeping these results, contains several low-complexity...

Fission yeast Cid12 is a member of the Cid1 family specialized poly(A) polymerases.Like cells lacking cid1, cid12⌬ mutants were shown to have checkpoint defects when DNA replication was inhibited.Here, we show that also required for faithful chromosome segregation and mutation amino acid residues predicted be essential polymerase activity resulted in loss function vivo.Cells had an increased failure rate due precocious sister chromatid cohesion at centromere but not along arms.In keeping...

In Schizosaccharomyces pombe, topoisomerase III is encoded by a single gene, top3(+), which essential for cell viability and proper chromosome segregation. Deletion of rqh1(+), encodes the sole RecQ family helicase in S. suppresses lethality caused loss top3. Here, we provide evidence suggesting that top3 mutants due to accumulation aberrant DNA structures arise during S phase, as judged pulsed-field gel electrophoresis. Using shut-off strain, show here depletion Top3 activates damage...

In this study we identified Pdc2, the fission yeast ortholog of human Pat1b protein, which forms a complex with Lsm1-7 and plays role in coupling deadenylation decapping. The involvement Pdc2 RNA degradation P-body function was also determined. We found that interacts Dcp2 is required for decapping vivo. Although not absolutely essential assembly, overexpression enhanced formation even absence Pdc1, functional homolog Edc4 indicating formation. Intriguingly, Lsm1 to accumulate nucleus,...

Posttranslational protein S-palmitoylation regulates the localization and function of its target proteins involved in diverse cellular processes including meiosis. In this study, we demonstrate that mediated by Erf2-Erf4 Akr1 palmitoylacyltransferases is required at multiple meiotic stages fission yeast Schizosaccharomyces pombe . We find for Ras1 cell periphery to enrich conjugation site mating pheromone response. absence Erf2 or Erf4, mutant cells are sterile. A role S-palmitoylating...

Schizosaccharomyces pombeRqh1 is a member of the RecQ DNA helicase family.Members this protein family are mutated in cancer predisposition diseases, causing Bloom's, Werner, and Rothmund-Thomson syndromes.Rqh1 forms complex with topoisomerase III proposed to process or disrupt aberrant recombination structures that arise during S phase allow proper chromosome segregation mitosis.Intriguingly, absence Rqh1, processing these appears be dependent on Rad3 (human ATR) manner distinct from its...

Pin1 is a peptidyl-prolyl isomerase that regulates the structure and function of eukaryotic RNA polymerase II (Pol II) through interaction with C-terminal domain (CTD) Rpb1, largest subunit Pol II. We demonstrated this important for cellular response to oxidative stress in fission yeast Schizosaccharomyces pombe. In stress, Atf1 transcription factor targets Sty1, mitogen-activated protein kinase (MAPK), specific stress-responsive promoters. Anchored Sty1 recruits direct association Rpb1-CTD...

Alanyl-tRNA synthetase retains a conserved prototype structure throughout its biology. Nevertheless, C-terminal domain (C-Ala) is highly diverged and has been shown to play role in either tRNA or DNA binding. Interestingly, we discovered that Caenorhabditis elegans cytoplasmic C-Ala (Ce-C-Alac) robustly binds both ligands. How Ce-C-Alac targets cognate whether similar feature mitochondrial counterpart remain elusive. We show the N- subdomains of are responsible for binding, respectively....