Browsing by Subject "Schizosaccharomyces japonicus"

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    Quorum sensing and stress-activated MAPK signaling repress yeast to hypha transition in the fission yeast Schizosaccharomyces japonicus
    (Public Library of Science, 2019-05) Gómez-Gil, Elisa; Franco Sánchez, Alejandro; Madrid, Marisa; Vázquea-Marín, Beatriz; Gacto, Mariano; Fenández-Breis, Jesualdo; Vicente-Soler, Jero; Soto, Teresa; Cansado Vizoso, José; Genética y Microbiología
    Quorum sensing (QS), a mechanism of microbial communication dependent on cell density, governs developmental decisions in many bacteria and in some pathogenic and non-pathogenic fungi including yeasts. In these simple eukaryotes this response is mediated by the release into the growth medium of quorum-sensing molecules (QSMs) whose concentration increases proportionally to the population density. To date the occurrence of QS is restricted to a few yeast species. We show that a QS mediated by the aromatic alcohols phenylethanol and tryptophol represses the dimorphic yeast to hypha differentiation in the fission yeast S. japonicus in response to an increased population density. In addition, the stress activated MAPK pathway (SAPK), which controls cell cycle progression and adaptation to environmental changes in this organism, constitutively represses yeast to hypha differentiation both at transcriptional and post-translational levels. Moreover, deletion of its main effectors Sty1 MAPK and Atf1 transcription factor partially suppressed the QS-dependent block of hyphal development under inducing conditions. RNAseq analysis showed that the expression of nrg1+, which encodes a putative ortholog of the transcription factor Nrg1 that represses yeast to hypha dimorphism in C. albicans, is downregulated both by QS and the SAPK pathway. Remarkably, Nrg1 may act in S. japonicus as an activator of hyphal differentiation instead of being a repressor. S. japonicus emerges as an attractive and amenable model organism to explore the QS mechanisms that regulate cellular differentiation in fungi.
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    Specific functional features of the cell integrity MAP Kinase pathway in the dimorphic fission yeast Schizosaccharomyces japonicus
    (MDPI, 2021-06-14) Gómez Gil, Elisa; Franco Sánchez, Alejandro; Vázquez Marín, Beatriz; Prieto Ruiz, Francisco; Pérez Díaz, Armando Jesús; Vicente Soler, Jerónima; Madrid Mateo, María Isabel; Soto Pino, Teresa; Cansado Vizoso, José; Genética y Microbiología; Facultades de la UMU::Facultad de Biología
    Mitogen activated protein kinase (MAPK) signaling pathways execute essential functions in eu-karyotic organisms by transducing extracellular stimuli into adaptive cellular responses. In the fis-sion yeast model Schizosaccharomyces pombe the cell integrity pathway (CIP) and its core effector, MAPK Pmk1, play a key role during regulation of cell integrity, cytokinesis, and ionic homeostasis. Schizosaccharomyces japonicus, another fission yeast species, shows remarkable differences with re-spect to S. pombe, including a robust yeast to hyphae dimorphism in response to environmental changes. We show that the CIP MAPK module architecture and its upstream regulators, PKC orthologs Pck1 and Pck2, are conserved in both fission yeast species. However, some of S. pombe’s CIP-related functions, such as cytokinetic control and response to glucose availability, are regulated differently in S. japonicus. Moreover, Pck1 and Pck2 antagonistically regulate S. japonicus hyphal differentiation through fine-tuning of Pmk1 activity. Chimeric MAPK-swapping experiments re-vealed that S. japonicus Pmk1 is fully functional in S. pombe, whereas S. pombe Pmk1 shows a limited ability to execute CIP functions and promote S. japonicus mycelial development. Our findings also suggest that a modified N-lobe domain secondary structure within S. japonicus Pmk1 has a major influence on the CIP signaling features of this evolutionarily diverged fission yeast.2021