Pseudohyphal differentiation in Komagataella phaffii: investigating the FLO gene family (FAIRE-seq)
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ABSTRACT:
ORGANISM(S): Komagataella phaffii
PROVIDER: GSE131290 | GEO | 2020/08/19
REPOSITORIES: GEO
Similar Datasets
Project description:The protein production host Komagataella phaffii has possess the ability to differentiate into pseudohyphal form when cultivated at slow growth rates (µ=0.05 h-1) in glucose-limited chemostats. In this study, we investigated the K. phaffii FLO gene family in the context of pseudohyphae formation. Transcriptional analysis helped us identify 3 possible responsible genes, FLO11, FLO400 and FLO5-1, all of which are under control of Flo8, a transcription factor whose disruption prevents pseudohyphae formation. Knocking out FLO11 revealed that this is not the sole protein responsible for this phenotype. Strikingly, the expression of FLO400 and FLO5-1 was negatively correlated with pseudohyphae formation, and shown to be under epigenetic control by FAIRE-Seq analysis. Knock outs of these two genes completely inhibited the appearance of pseudohyphal cells and prevented the expression of FLO11. Even though the mechanism is unclear at present, we propose that in K. phaffii Flo400 and/or Flo5-1 act as upstream signals that lead to the induction of FLO11 expression upon severe glucose limitation in chemostats at slow growth rate, and that the expression of FLO400 and FLO5-1 is controlled by epigenetic silencing, which acts independently from the general activation of FLO gene expression by the transcriptional regulator Flo8.
2020-08-19 | GSE131106 | GEO
Project description:Effect of either FLO8 or MSS11 deletion and -overexpression on yeast transcript profiles compared to wild type in laboratory yeast strains Σ1278b and S288c - also the effect of FLO11 (MUC1) overexpression in the Σ1278b genetic background The aim of this study was to (1) perform a repeat analysis (to improve statistical analysis of these data sets) similar to data submitted previously (GSE17716) and also (2) study the effect of FLO11 over-expression on the transcriptome. Background: The outer cell wall of the yeast Saccharomyces cerevisiae serves as the interface with the surrounding environment and defines cell-cell and cell-surface interactions. Many of these interactions are facilitated by specific adhesins that belong to the Flo protein family. This family of mannoproteins has been implicated in phenotypes such as flocculation and substrate adhesion as well as pseudohyphal growth. Genetic data strongly suggest that individual Flo proteins are responsible for many specific cellular adhesion phenotypes. However, it remains unclear whether such phenotypes are determined solely by the nature of the expressed FLO genes or rather the result of a combination of FLO gene expression and other cell wall properties and cell wall proteins. Mss11p has been shown to be a central element of FLO1 and FLO11 gene regulation and acts together with the cAMP-PKA-dependent transcription factor Flo8p. We use genome wide transcript analysis to identify genes that are direct ly or indirectly regulated by Mss11p in the genetic backgrounds: Sigma1278b and S288c. Sigma 1278b is the strain historically used for the study of pseudohyphae (FLO11 expression) but we also included S288c as this strain is widely used in the research community and was used to determine the first full genome sequence (Thus correspond with SGD information). We also compare this data with transcriptome data from Sigma 1278b yeast over-expressing FLO8 to compare similarities/differences between these two signalling factors. Finally the effect of FLO11 over-expression in Sigma1278b on global transcription is studied so that we can differentiate between "direct" gene targets of Flo8p or Mss11p, and those regulated as a result by the "indirect" effect caused by modified cell wall Flo11p levels. We used two laboratory yeast strains that behave different with regard to adhesion phenotypes. By comparing yeast deleted in either FLO8 or MSS11 to wild type, or yeast overexpressing these genes, in both genetic backgrounds, we investigate the role of Flo8p and Mss11p on yeast transcription. In addition the effect of the over-expression of the adhesin gene FLO11 was studied in Sigma 1278b. By using similar growth conditions to what we use for adhesion phenotype determination we aim to correlate transcription profile changes to yeast behaviour (phenotypes).
2011-09-20 | E-GEOD-29371 | biostudies-arrayexpress
Project description:Effect of either FLO8 or MSS11 deletion and -overexpression on yeast transcript profiles compared to wild type in laboratory yeast strains Σ1278b and S288c - also the effect of FLO11 (MUC1) overexpression in the Σ1278b genetic background The aim of this study was to (1) perform a repeat analysis (to improve statistical analysis of these data sets) similar to data submitted previously (GSE17716) and also (2) study the effect of FLO11 over-expression on the transcriptome. Background: The outer cell wall of the yeast Saccharomyces cerevisiae serves as the interface with the surrounding environment and defines cell-cell and cell-surface interactions. Many of these interactions are facilitated by specific adhesins that belong to the Flo protein family. This family of mannoproteins has been implicated in phenotypes such as flocculation and substrate adhesion as well as pseudohyphal growth. Genetic data strongly suggest that individual Flo proteins are responsible for many specific cellular adhesion phenotypes. However, it remains unclear whether such phenotypes are determined solely by the nature of the expressed FLO genes or rather the result of a combination of FLO gene expression and other cell wall properties and cell wall proteins. Mss11p has been shown to be a central element of FLO1 and FLO11 gene regulation and acts together with the cAMP-PKA-dependent transcription factor Flo8p. We use genome wide transcript analysis to identify genes that are direct ly or indirectly regulated by Mss11p in the genetic backgrounds: Sigma1278b and S288c. Sigma 1278b is the strain historically used for the study of pseudohyphae (FLO11 expression) but we also included S288c as this strain is widely used in the research community and was used to determine the first full genome sequence (Thus correspond with SGD information). We also compare this data with transcriptome data from Sigma 1278b yeast over-expressing FLO8 to compare similarities/differences between these two signalling factors. Finally the effect of FLO11 over-expression in Sigma1278b on global transcription is studied so that we can differentiate between "direct" gene targets of Flo8p or Mss11p, and those regulated as a result by the "indirect" effect caused by modified cell wall Flo11p levels.
2011-09-21 | GSE29371 | GEO
Project description:Pseudohyphal differentiation in Komagataella phaffii: investigating the FLO gene family
| PRJNA542662 | ENA
Project description:Pseudohyphal differentiation in Komagataella phaffii: investigating the FLO gene family (FAIRE-seq)
| PRJNA543126 | ENA
Project description:Pseudohyphal growth is a developmental pathway seen in some strains of yeast, in which cells elongate and form multicellular filaments in response to environmental stresses. Regulation of this process is complex and involves multiple signaling pathways and a large number of transcription factors (TFs). We used multiplexed transposon M-bM-^@M-^\Calling CardsM-bM-^@M-^] to simultaneously record the genome-wide binding patterns of 28 TFs in nitrogen-starved yeast. We were able to identify TF targets relevant for pseudohyphal growth, producing a detailed map of the regulatory network that governs this process. Using tools from graph theory, we identified 8 transcription factors that lie at the center of this network, including Flo8, Mss11, and Mfg1, which bind as a complex. Surprisingly, the DNA binding preferences for these key transcription factors were not known. Using Calling Card data, we predicted the in vivo DNA binding motif for the Flo8-Mss11-Mfg1 complex and validated it using a reporter assay. We found that this complex binds several important targets, including FLO11, at both their promoter and termination sequences. We demonstrated that this binding pattern is the result of DNA-looping, which regulates the transcription of these targets and is stabilized by an interaction with the nuclear pore complex. This looping provides yeast cells with a transcriptional memory, enabling them to more rapidly execute the filamentous growth program when nitrogen-starved if they have been previously exposed to this condition. These data contain mapped insertion sites from Ty5 transposon "Calling Cards" in M-NM-#1278b yeast sequenced using an Illumina Hiseq. Other sequencing data present are RNA-seq reads.
2014-02-11 | E-GEOD-54831 | biostudies-arrayexpress
Project description:Pseudohyphal growth is a developmental pathway seen in some strains of yeast, in which cells elongate and form multicellular filaments in response to environmental stresses. Regulation of this process is complex and involves multiple signaling pathways and a large number of transcription factors (TFs). We used multiplexed transposon “Calling Cards” to simultaneously record the genome-wide binding patterns of 28 TFs in nitrogen-starved yeast. We were able to identify TF targets relevant for pseudohyphal growth, producing a detailed map of the regulatory network that governs this process. Using tools from graph theory, we identified 8 transcription factors that lie at the center of this network, including Flo8, Mss11, and Mfg1, which bind as a complex. Surprisingly, the DNA binding preferences for these key transcription factors were not known. Using Calling Card data, we predicted the in vivo DNA binding motif for the Flo8-Mss11-Mfg1 complex and validated it using a reporter assay. We found that this complex binds several important targets, including FLO11, at both their promoter and termination sequences. We demonstrated that this binding pattern is the result of DNA-looping, which regulates the transcription of these targets and is stabilized by an interaction with the nuclear pore complex. This looping provides yeast cells with a transcriptional memory, enabling them to more rapidly execute the filamentous growth program when nitrogen-starved if they have been previously exposed to this condition.
2014-02-11 | GSE54831 | GEO
Project description:When grown on solid substrates, different microorganisms often form colonies with very specific morphologies. Whereas the pioneers of microbiology often used colony morphology to discriminate between species and strains, the phenomenon has not received much recent attention. In this study, we use a genome-wide assay in the model yeast Saccharomyces cerevisiae to identify all genes that affect colony morphology. We show that several major signaling cascades, including the MAPK, TORC, SNF1 and RIM101 pathways play a role, indicating that morphological changes are a reaction to changing environments. Other genes that affect colony morphology are involved in protein sorting and epigenetic regulation. Interestingly, the screen reveals only few genes that are likely to play a direct role in establishing colony morphology, one notable exception being FLO11, a gene encoding a cell-surface adhesin that has already been implicated in colony morphology, biofilm formation, and invasive and pseudohyphal growth. Using a series of modified promoters to tune FLO11 expression, we confirm the central role of Flo11 and show that differences in FLO11 expression result in distinct colony morphologies. Together, our results provide a first comprehensive looks at the complex genetic network that underlies the diversity in the morphologies of yeast colonies. Microarrays were used to measure gene expression between WT and FLO11 mutants in both liquid and solid medium to assess which genes induce altered colony morphology through FLO11.
2012-04-27 | E-GEOD-36151 | biostudies-arrayexpress
Project description:Candida albicans, the most common cause of human fungal infections, undergoes a reversible morphological transition from yeast to pseudohyphal and hyphal filaments, which is required for virulence. For many years, the relationship between global gene expression patterns associated with determination of specific C. albicans morphologies has remained obscure. Using a strain that can be genetically manipulated to sequentially transition from yeast to pseudohyphae to hyphae in the absence of complex environmental cues and upstream signaling pathways, we demonstrate by whole-genome transcriptional profiling that genes associated with pseudohyphae represent a subset of those associated hyphae and are generally expressed at lower levels; interestingly, no genes appeared to be expressed exclusively in pseudohyphae. Our results also strongly suggest that in addition to dosage, extended duration of filament-specific gene expression is sufficient to drive the C. albicans yeast-pseudohyphal-hyphal transition. Finally, we describe the first transcriptional profile of the C. albicans reverse hyphal-pseudohyphal-yeast transition and demonstrate that this transition not only involves down-regulation of known hyphal-specific genes but also differential expression of additional genes which have not previously been associated with the forward transition, including many involved in protein synthesis. These findings provide new insight into genome-wide mechanisms important for determining fungal morphology and suggest that in addition to similarities, there are also fundamental differences in global gene expression as pathogenic filamentous fungi undergo forward and reverse morphological transitions.
2012-12-12 | GSE39677 | GEO
Project description:When grown on solid substrates, different microorganisms often form colonies with very specific morphologies. Whereas the pioneers of microbiology often used colony morphology to discriminate between species and strains, the phenomenon has not received much recent attention. In this study, we use a genome-wide assay in the model yeast Saccharomyces cerevisiae to identify all genes that affect colony morphology. We show that several major signaling cascades, including the MAPK, TORC, SNF1 and RIM101 pathways play a role, indicating that morphological changes are a reaction to changing environments. Other genes that affect colony morphology are involved in protein sorting and epigenetic regulation. Interestingly, the screen reveals only few genes that are likely to play a direct role in establishing colony morphology, one notable exception being FLO11, a gene encoding a cell-surface adhesin that has already been implicated in colony morphology, biofilm formation, and invasive and pseudohyphal growth. Using a series of modified promoters to tune FLO11 expression, we confirm the central role of Flo11 and show that differences in FLO11 expression result in distinct colony morphologies. Together, our results provide a first comprehensive looks at the complex genetic network that underlies the diversity in the morphologies of yeast colonies.
2012-04-28 | GSE36151 | GEO