The TOR pathway plays pleiotropic roles in growth and stress responses of the fungal pathogen Cryptococcus neoformans
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PROVIDER: PRJNA530555 | ENA |
REPOSITORIES: ENA
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Project description:The target of rapamycin (TOR) pathway is an evolutionarily conserved signal transduction system that is activated by varying nutrient and environmental signals and governs a plethora of eukaryotic biological processes, but its role in Cryptococcus neoformans remains elusive. In this study, we investigated the TOR pathway by functionally characterizing two Tor-like kinases, Tor1 and Tlk1, in C. neoformans. We successfully deleted TLK1, but not TOR1. TLK1 deletion did not result in any evident in vitro phenotypes, suggesting that Tlk1 is mainly dispensable for the growth of C. neoformans. We further demonstrated that Tor1, but not Tlk1, is essential and the target of rapamycin by constructing and analyzing conditionally regulated strains and sporulation analysis of heterozygous mutants in the diploid strain background. To analyze the functions of Tor1 in more detail, we constructed constitutive TOR1 overexpression strains. Tor1 negatively regulated thermotolerance and the DNA damage response, which are two important virulence factors of C. neoformans. We also found that TOR1 overexpression reduced Mpk1 phosphorylation, which is required for cell wall integrity and thermoresistance, and Rad53 phosphorylation, which governs the DNA damage response pathway. Tor1 is localized to the cytoplasm but enriched in the vacuole membrane. Phosphoproteomics and transcriptomics revealed that Tor1 regulates a variety of biological processes, including metabolic processes, cytoskeleton organization, ribosome biogenesis, autophagy, and stress response. TOR inhibition by rapamycin caused actin depolarization in a Tor1-dependent manner. Finally, screening rapamycin-sensitive and -resistant kinase and transcription factor mutants revealed that the TOR pathway may crosstalk with a number of signaling pathways, including the Hog1 pathway. In conclusion, our study demonstrates that a single Tor1 kinase plays a variety of roles in the fungal meningitis pathogen C. neoformans.
2019-04-03 | GSE129227 | GEO
Project description:Cryptococcus spp. are environmental fungi that first must adapt to the host environment before they can cause life-threatening meningitis in immunocompromised patients. Host CO2 concentrations are 100-fold higher than the external environment and strains unable to grow at host CO2 concentrations are not pathogenic. Using a genetic screening and transcriptional profiling approach, we found that the TOR pathway is critical for C. neoformans adaptation to host CO2 partly through Ypk1-dependent remodeling of phosphatidylserine asymmetry at the plasma membrane. We also identified a C. neoformans ABC/PDR transporter (PDR9) that is highly expressed in CO2-sensitive environmental strains, suppresses CO2-induced phosphatidylserine remodeling, and increases susceptibility to host concentrations of CO2. Interestingly, regulation of plasma membrane lipid asymmetry by the TOR-Ypk1 axis is distinct in C. neoformans compared to S. cerevisiae. Finally, host CO2 concentrations suppress the C. neoformans pathways that respond to host temperature (Mpk1) and pH (Rim101), indicating that host adaptation requires a stringent balance among distinct stress responses.
2023-10-24 | GSE241788 | GEO
Project description:The target of rapamycin (TOR) pathway is an evolutionarily conserved signal transduction system that governs a plethora of eukaryotic biological processes, but its role in Cryptococcus neoformans remains elusive. In this study, we investigated the TOR pathway by functionally characterizing two Tor-like kinases, Tor1 and Tlk1, in C. neoformans We successfully deleted TLK1, but not TOR1TLK1 deletion did not result in any evident in vitro phenotypes, suggesting that Tlk1 is dispensable for the growth of C. neoformans We demonstrated that Tor1, but not Tlk1, is essential and the target of rapamycin by constructing and analyzing conditionally regulated strains and sporulation analysis of heterozygous mutants in the diploid strain background. To further analyze the Tor1 function, we constructed constitutive TOR1 overexpression strains. Tor1 negatively regulated thermotolerance and the DNA damage response, which are two important virulence factors of C. neoformansTOR1 overexpression reduced Mpk1 phosphorylation, which is required for cell wall integrity and thermoresistance, and Rad53 phosphorylation, which governs the DNA damage response pathway. Tor1 is localized to the cytoplasm, but enriched in the vacuole membrane. Phosphoproteomics and transcriptomics revealed that Tor1 regulates a variety of biological processes, including metabolic processes, cytoskeleton organization, ribosome biogenesis, and stress response. TOR inhibition by rapamycin caused actin depolarization in a Tor1-dependent manner. Finally, screening rapamycin-sensitive and -resistant kinase and transcription factor mutants revealed that the TOR pathway may crosstalk with a number of stress signaling pathways. In conclusion, our study demonstrates that a single Tor1 kinase plays pleiotropic roles in C. neoformans.
| S-EPMC6707454 | biostudies-literature
Project description:A family of APSES transcription factor is known to be fungal-specific transcriptional regulators and play important roles in governing growth, differentiation, and virulence of diverse fungal pathogens. Yet none of APSES-like transcription factors have been identified and investigated in a basidiomycetous fungal pathogen, Cryptococcus neoformans. In the present study we discovered an APSES-like transcription factor, mbs1 (Mbp1/Swi4-like APSES protein 1), as one of novel flucytosine-responsive genes (total 194 genes) identified through comparative transcriptome analysis of C. neoformans hybrid sensor kinase mutants, tco1 and tco2 mutants, which displayed differential flucytosine-susceptibility. Supporting the microarray data, Northern blot and quantitative RT-PCR analysis confirmed that expression of mbs1 is rapidly induced in response to flucytosine in the wild-type strain, but not in the tco1 and tco2 mutants. Furthermore, C. neoformans with deletion of the mbs1 gene exhibited increased susceptibility to flucytosine. Intriguingly, mbs1 plays pleiotropic roles in diverse cellular process of C. neoformans. mbs1 positively regulates ergosterol biosynthesis and thereby its inhibition confers increased susceptibility and resistance to amphotericin B and azole drugs, respectively. mbs1 is also involved in DNA damage repair counteracting genotoxic stresses. During sexual differentiation mbs1 represses pheromone production, but promotes cell-cell fusion. Furthermore mbs1 is required for production of antioxidant melanin pigment and full virulence of C. neoformans. Finally we also performed DNA microarrray analysis to identify mbs1-regulated genes in C. neoformans. A majority of them were found to be involved in cell cycle regulation and DNA repair. Therefore, this study provides a novel antifungal therapeutic method for treatment of cryptococcosis.
2011-06-23 | GSE30156 | GEO
Project description:WD40 motif-containing Msi1-like (MSIL) proteins play pleiotropic cellular functions as a negative regulator of the Ras/cAMP-pathways and a component of chromatin assembly factor-I (CAF-I), and yet have not been studied in fungal pathogens. Here we identified and characterized an MSIL protein, Msl1, in Cryptococcus neoformans, which can cause fatal meningoencephalitis in humans. Notably, Msl1 was not a functional ortholog for the yeast Msi1 but played pleiotropic roles in C. neoformans in both cAMP-dependent and -independent manners but mainly Ras-independently. Msl1 negatively controlled antioxidant melanin production and sexual differentiation, which can be repressed by inhibiting the cAMP-signaling pathways. In contrast, Msl1 controlled thermotolerance, diverse stress responses, and antifungal drugs resistance in Ras/cAMP-independent manners. Cac2, which is the second CAF-I component, appeared to play both redundant and distinct function with Msl1. Msl1 is required for full virulence of C. neoformans. Transcriptome and proteomic analysis identified a group of Msl1-regulated genes or -interacting proteins, respectively, which mostly include stress-related genes, including HSP12, HSP78, SSA1, SSA4, and STM1. Furthermore, we identified the third putative component of CAF-1, Rlf2, in C. neoformans. In conclusion, this study demonstrated the pleiotropic roles of Msl1 in human fungal pathogen C. neoformans, providing a novel antifungal therapeutic target. There is more than 95% genome homology between JEC21 and H99. Therefore, 6 slides of JEC21 (Cryptococcus neoformans var. neoformans serotype D) 70-mer oligos are used in this analysis. Total RNAs are extracted from 2 strains from H99 (H99 wild-type strain (Cryptococcus neoformans var. grubii serotype A), msl1M-NM-^T). 3 biological replicate experiments are performed for each strain. We use the mix of all total RNAs from this experiment as the control RNA. We use Cy3 as the test sample dye and Cy5 as the control dye.
2012-08-23 | E-GEOD-40303 | biostudies-arrayexpress
Project description:WD40 motif-containing Msi1-like (MSIL) proteins play pleiotropic cellular functions as a negative regulator of the Ras/cAMP-pathways and a component of chromatin assembly factor-I (CAF-I), and yet have not been studied in fungal pathogens. Here we identified and characterized an MSIL protein, Msl1, in Cryptococcus neoformans, which can cause fatal meningoencephalitis in humans. Notably, Msl1 was not a functional ortholog for the yeast Msi1 but played pleiotropic roles in C. neoformans in both cAMP-dependent and -independent manners but mainly Ras-independently. Msl1 negatively controlled antioxidant melanin production and sexual differentiation, which can be repressed by inhibiting the cAMP-signaling pathways. In contrast, Msl1 controlled thermotolerance, diverse stress responses, and antifungal drugs resistance in Ras/cAMP-independent manners. Cac2, which is the second CAF-I component, appeared to play both redundant and distinct function with Msl1. Msl1 is required for full virulence of C. neoformans. Transcriptome and proteomic analysis identified a group of Msl1-regulated genes or -interacting proteins, respectively, which mostly include stress-related genes, including HSP12, HSP78, SSA1, SSA4, and STM1. Furthermore, we identified the third putative component of CAF-1, Rlf2, in C. neoformans. In conclusion, this study demonstrated the pleiotropic roles of Msl1 in human fungal pathogen C. neoformans, providing a novel antifungal therapeutic target.
2012-08-23 | GSE40303 | GEO
Project description:AtDXO1 possesses deNADding and exonuclease activities and plays pleiotropic roles in gene regulation
| PRJNA548351 | ENA
Project description:To investigate the pleiotropic roles of Lkh1 in stress response and virulence, we constructed lkh1∆ mutant strains. In this study, we found that Tor1 was an upstream regulator of Lkh1 in C. neoformans. We then performed gene expression profiling analysis to elucidate signaling circuitry downstream of CnLkh1 in the TOR1-Lkh1 pathway using data obtained from RNA seq of 2 different strains (WT of lkh1∆ mutant) with or without rapamycin treatment.
2023-12-31 | GSE233612 | GEO
Project description:gnp_blan06_torpten - rnai tor time course - The impact of the TOR pathway on growth and stress responses. Modification of translational and transcriptional profiles in Tor-inducible RNAi mutants and identification of TOR targets.
2011-01-07 | GSE25701 | GEO
Project description:ra03-07_tor - tor - Study of 2 TOR mutants (7817 Strong, 7846 weak) - Mutant vs wild type on different nitrogen conditions (10mM=control and 100uM) Keywords: treated vs untreated comparison,wt vs mutant comparison
2007-06-20 | GSE7987 | GEO