Project description:This SuperSeries is composed of the following subset Series: GSE32550: A conserved transcriptional regulator governs fungal morphology in widely diverged species [expression data] GSE32557: A conserved transcriptional regulator governs fungal morphology in widely diverged species [ChIP-chip, Transcriptional regulation by Mit1 and orthologs] Refer to individual Series
Project description:A conserved transcriptional regulator governs fungal morphology in widely diverged species [ChIP-chip, Transcriptional regulation by Mit1 and orthologs]
Project description:In this paper, we examine orthologs of a transcriptional regulator in three fungal species, Saccharomyces cerevisiae, Candida albicans, and Histoplasma capsulatum. We show that, despite an estimated 600 million years since those species diverged from a common ancestor, Wor1 in C. albicans, Ryp1 in H. capsulatum, and Mit1 in S. cerevisiae recognize the same DNA motif. Previous work established that Wor1 regulates white-opaque switching in C. albicans and that its ortholog Ryp1 regulates the yeast to mycelial transition in H. capsulatum. Here we show that the ortholog Mit1 in S. cerevisiae also regulates a morphological transition, in this case pseudohyphal growth. Full genome chromatin immunoprecipitation experiments show that Mit1 binds to the control regions of approximately 94 genes including the previously known regulators of pseudohyphal growth. Through a comparison of full genome chromatin immunoprecipitation experiments for Mit1 in S. cerevisiae, Wor1 in C. albicans, and Wor1 ectopically expressed in S. cerevisiae, we conclude that genes controlled by the orthologous regulators overlap only slightly between these two species. We suggest that the ancestral Wor1/Mit1/Ryp1 protein controlled aspects of cell morphology and that evolutionary movement of genes in and out of the Wor1/Mit1/Ryp1 regulon is responsible, in part, for the differences of morphological forms among these species. Consistent with this idea, ectopic expression of C. albicans Wor1 or H. capsulatum Ryp1 can drive the pseudohyphal growth program in S. cerevisiae. IP strains were compared to untagged or deletion control strains
Project description:In this paper, we examine orthologs of a transcriptional regulator in three fungal species, Saccharomyces cerevisiae, Candida albicans, and Histoplasma capsulatum. We show that, despite an estimated 600 million years since those species diverged from a common ancestor, Wor1 in C. albicans, Ryp1 in H. capsulatum, and Mit1 in S. cerevisiae recognize the same DNA motif. Previous work established that Wor1 regulates white-opaque switching in C. albicans and that its ortholog Ryp1 regulates the yeast to mycelial transition in H. capsulatum. Here we show that the ortholog Mit1 in S. cerevisiae also regulates a morphological transition, in this case pseudohyphal growth. Full genome chromatin immunoprecipitation experiments show that Mit1 binds to the control regions of approximately 94 genes including the previously known regulators of pseudohyphal growth. Through a comparison of full genome chromatin immunoprecipitation experiments for Mit1 in S. cerevisiae, Wor1 in C. albicans, and Wor1 ectopically expressed in S. cerevisiae, we conclude that genes controlled by the orthologous regulators overlap only slightly between these two species. We suggest that the ancestral Wor1/Mit1/Ryp1 protein controlled aspects of cell morphology and that evolutionary movement of genes in and out of the Wor1/Mit1/Ryp1 regulon is responsible, in part, for the differences of morphological forms among these species. Consistent with this idea, ectopic expression of C. albicans Wor1 or H. capsulatum Ryp1 can drive the pseudohyphal growth program in S. cerevisiae.
Project description:In this paper, we examine orthologs of a transcriptional regulator in three fungal species, Saccharomyces cerevisiae, Candida albicans, and Histoplasma capsulatum. We show that, despite an estimated 600 million years since those species diverged from a common ancestor, Wor1 in C. albicans, Ryp1 in H. capsulatum, and Mit1 in S. cerevisiae recognize the same DNA motif. Previous work established that Wor1 regulates white-opaque switching in C. albicans and that its ortholog Ryp1 regulates the yeast to mycelial transition in H. capsulatum. Here we show that the ortholog Mit1 in S. cerevisiae also regulates a morphological transition, in this case pseudohyphal growth. Full genome chromatin immunoprecipitation experiments show that Mit1 binds to the control regions of approximately 94 genes including the previously known regulators of pseudohyphal growth. Through a comparison of full genome chromatin immunoprecipitation experiments for Mit1 in S. cerevisiae, Wor1 in C. albicans, and Wor1 ectopically expressed in S. cerevisiae, we conclude that genes controlled by the orthologous regulators overlap only slightly between these two species. We suggest that the ancestral Wor1/Mit1/Ryp1 protein controlled aspects of cell morphology and that evolutionary movement of genes in and out of the Wor1/Mit1/Ryp1 regulon is responsible, in part, for the differences of morphological forms among these species. Consistent with this idea, ectopic expression of C. albicans Wor1 or H. capsulatum Ryp1 can drive the pseudohyphal growth program in S. cerevisiae. Replicate experiments for each of four strains compared with reference sample - WT, a Mit1 deletion haploid A strain, a Yhr177w deletion haploid A strain, and a double deletion haploid A strain. All were in the sigma 2000 background.
Project description:Asexual development is fundamental to the ecology and lifestyle of filamentous fungi and can facilitate both plant and human infection. In the filamentous fungal genus Aspergillus, the production of asexual spores is primarily governed by the BrlA-AbaA-WetA central regulatory cascade. The final step in this cascade, which is controlled by the WetA protein, not only governs cellular development (i.e., the morphological differentiation of spores) but also ensures its coupling with chemical development (i.e., the coordinated production and deposition of diverse secondary metabolites, such as aflatoxins, into spores). While the wetA gene is conserved across the genus Aspergillus, the structure and degree of conservation of the BrlA-AbaA-WetA regulatory cascade and the broader wetA gene regulatory network (GRN) remain largely unknown. We carried out comparative transcriptome analyses between wetA null mutant and wild type (WT) asexual spores in three representative species spanning the diversity of the genus Aspergillus: the genetic model A. nidulans, the agricultural pest A. flavus, and the human pathogen A. fumigatus. We discovered that WetA regulates asexual sporulation in all three species via a negative feedback loop that represses BrlA, the cascade’s first step. Furthermore, ChIP-seq experiments in A. nidulans asexual spores suggest that WetA is a DNA-binding protein that interacts with a novel regulatory element, which we term the WetA Response Element (WRE). Interestingly, the WRE is found completely conserved in the non-coding region upstream of the wetA translation start site of many diverse Aspergillus genomes. In contrast, several global transcriptional regulators, most notably those in the velvet complex (veA, velB, and laeA) known to regulate the coupling between asexual development and production of secondary metabolites, show species-specific regulatory patterns. These results suggest that the BrlA-AbaA-WetA cascade’s regulatory role in cellular and chemical development of asexual spores is functionally conserved, but that the WetA-associated GRN has diverged during Aspergillus evolution. This entry is for the ChIP-seq data.
Project description:Mediator is an essential, evolutionarily conserved co-regulator of RNA polymerase II. Studies in model yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe showed remarkably conserved roles for Mediator despite high species divergence, and thus whether Mediator contributed to establishment of species-specific gene expression programs within related fungal species remains an open question. Here we show that in the fungal pathogen Candida albicans, the Mediator middle domain subunit Med31 has a conserved role with non-pathogenic model yeasts in regulation of Ace2-dependent cytokinesis genes and stress responses, but also additional roles in the transcription of genes associated with virulence traits: genes related to filamentous growth and gene families expanded in pathogenic vs non-pathogenic yeasts, such as the ALS adhesins and the FGR6 family of filamentous growth regulators. Consistently, Med31 is required for two key virulence attributes of C. albicans: filamentous growth and biofilm formation. Unlike our data in C. albicans, no role for Med31 in adhesin expression has been reported in model yeasts. To show biological relevance for the control over adhesin gene expression, we demonstrate that ALS1 is a relevant Med31 target for development of biofilms. Collectively, our data supports a role for Med31 in shaping species-specific gene expression in related fungal species. Two-color experimental design comparing cells with a ?med31 mutation with a control strain in which the MED31 gene was reintroduced. RNA from each replicate came from independent cultures.
Project description:Skn7 is a conserved fungal heat shock factor-type transcriptional regulator. It participates in maintaining cell wall integrity and regulates the osmotic/oxidative stress response (OSR) in S. cerevisiae, where it is part of a two-component signal transduction system. Here, we comprehensively address the function of Skn7 in the human fungal pathogen Candida albicans. We provide evidence reinforcing functional divergence, with loss of the cell wall/osmotic stress-protective roles and acquisition of the ability to regulate morphogenesis on solid medium. Mapping of the Skn7 transcriptional circuitry, through combination of genome-wide expression and location technologies, pointed to a dual regulatory role encompassing OSR and filamentous growth. Genetic interaction analyses revealed close functional interactions between Skn7 and master regulators of morphogenesis, including Efg1, Cph1 and Ume6. Intracellular biochemical assays revealed that Skn7 is crucial for limiting the accumulation of reactive oxygen species (ROS) during filamentous growth on solid medium. Interestingly, functional domain mapping using site-directed mutagenesis allowed decoupling of Skn7 function in morphogenesis from protection against intracellular ROS. Our work identifies Skn7 as an integral part of the transcriptional circuitry controlling C. albicans filamentous growth and illuminates how C. albicans relies on an evolutionarily-conserved regulator to protect itself from intracellular ROS during morphological development.
Project description:In this paper, we examine orthologs of a transcriptional regulator in three fungal species, Saccharomyces cerevisiae, Candida albicans, and Histoplasma capsulatum. We show that, despite an estimated 600 million years since those species diverged from a common ancestor, Wor1 in C. albicans, Ryp1 in H. capsulatum, and Mit1 in S. cerevisiae recognize the same DNA motif. Previous work established that Wor1 regulates white-opaque switching in C. albicans and that its ortholog Ryp1 regulates the yeast to mycelial transition in H. capsulatum. Here we show that the ortholog Mit1 in S. cerevisiae also regulates a morphological transition, in this case pseudohyphal growth. Full genome chromatin immunoprecipitation experiments show that Mit1 binds to the control regions of approximately 94 genes including the previously known regulators of pseudohyphal growth. Through a comparison of full genome chromatin immunoprecipitation experiments for Mit1 in S. cerevisiae, Wor1 in C. albicans, and Wor1 ectopically expressed in S. cerevisiae, we conclude that genes controlled by the orthologous regulators overlap only slightly between these two species. We suggest that the ancestral Wor1/Mit1/Ryp1 protein controlled aspects of cell morphology and that evolutionary movement of genes in and out of the Wor1/Mit1/Ryp1 regulon is responsible, in part, for the differences of morphological forms among these species. Consistent with this idea, ectopic expression of C. albicans Wor1 or H. capsulatum Ryp1 can drive the pseudohyphal growth program in S. cerevisiae.