Project description:Gene expression was quantified in crz1 delete S. cerevisae cells over a time course following calcineurin activation by CaCl2. Cells were pretreated with buffer or the calcineurin inhibitor FK506 to allow the identification of calcineurin-regulated genes. A strain with a calcineurin-resistant mutation in the transcription factor Hcm1 was also examined. We show that calcineurin activation leads to downregulation of a many clusters of cell cycle-regulated genes, including those expressed at the G1/S and G2/M transitions.
Project description:Gene expression was quantified in crz1 hog1 delete S. cerevisae cells over a time course following calcineurin activation by CaCl2. Cells were pretreated with buffer or the calcineurin inhibitor FK506 to allow the identification of calcineurin-regulated genes. We show that calcineurin-dependent downregulation of G1/S genes is partly dependent on the osmostress-activated kinase Hog1.
Project description:In Saccharomyces cerevisiae, the Ca2+/calmodulin-dependent protein phosphatase, calcineurin, is activated by specific environmental conditions, including exposure to Ca2+ and Na+, and induces gene expression by regulating the Crz1p/Tcn1p transcription factor. We used DNA microarrays to perform a comprehensive analysis of calcineurin/Crz1p-dependent gene expression following addition of Ca2+ (200 mM) or Na+ (0.8 M) to yeast. 163 genes exhibited increased expression that was reduced 50% or more by calcineurin inhibition. These calcineurin dependent genes function in signaling pathways, ion/small molecule transport, cell wall maintenance, vesicular transport, and include many open reading frames of heretofore-unknown function. Three distinct gene classes were defined: 28 genes displayed calcineurin-dependent induction in response to Ca2+ and Na+, 125 showed calcineurin-dependent expression following Ca2+ but not Na+ addition, and 10 were regulated by calcineurin in response to Na+ but not Ca2+. Analysis of crz1D cells established Crz1p as the major effecter of calcineurin-regulated gene expression in yeast. We identified the Crz1p binding site as 5-GNGGC(G/T)CA-3 by in vitro site selection. A similar sequence, 5-GAGGCTG-3, was identified as a common sequence motif in the upstream regions of calcineurin/Crz1p-dependent genes. This finding is consistent with direct regulation of these genes by Crz1p. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
Project description:Calcineurin is a highly conserved Ca2+/calmodulin-dependent serine/threonine-specific protein phosphatase that orchestrates cellular Ca2+ signaling responses. In Cryptococcus neoformans, calcineurin is activated by multiple stresses including high temperature, and is essential for stress adaptation and virulence. The transcription factor Crz1 is a major calcineurin effector in Saccharomyces cerevisiae and other fungi. Calcineurin dephosphorylates Crz1, thereby enabling Crz1 nuclear translocation and transcription of target genes. Here we show that Crz1 is dephosphorylated by calcineurin, and crz1Δ mutants display phenotypes intermediate between wild-type and calcineurin mutants. RNA-sequencing revealed 102 genes that are regulated in a calcineurin/Crz1-dependent manner at 37°C. 99 genes were down-regulated in cna1Δ and crz1Δ mutants, indicating these genes are normally activated by the calcineurin/Crz1 pathway at high temperature. About 58% of calcineurin-Crz1 target genes have unknown functions, while genes with known or predicted functions are involved in cell wall remodeling, calcium transport, and pheromone production. Surprisingly, only five genes have orthologs known to be calcineurin/Crz1-dependent in S. cerevisiae. 393 genes are independently regulated by calcineurin, and Crz1 regulates 59 genes independently of calcineurin. Taken together, these results indicate that the calcineurin/Crz1-dependent pathway controls a transcriptional circuit that has been extensively rewired in C. neoformans compared to S. cerevisiae. Given the intermediate crz1Δ mutant phenotype, and our recent evidence for a calcineurin regulatory network impacting mRNA in P-bodies and stress granules independently of Crz1, calcineurin likely acts on factors beyond Crz1 that govern mRNA expression/stability to operate a branched transcriptional/post-transcriptional stress response network necessary for fungal virulence. Taken together, our findings reveal the core calcineurin-Crz1 stress response cascade is maintained from ascomycetes to a pathogenic basidiomycete fungus, but its output has been extensively rewired to promote fungal virulence.
Project description:In Saccharomyces cerevisiae, the Ca2+/calmodulin-dependent protein phosphatase, calcineurin, is activated by specific environmental conditions, including exposure to Ca2+ and Na+, and induces gene expression by regulating the Crz1p/Tcn1p transcription factor. We used DNA microarrays to perform a comprehensive analysis of calcineurin/Crz1p-dependent gene expression following addition of Ca2+ (200 mM) or Na+ (0.8 M) to yeast. 163 genes exhibited increased expression that was reduced 50% or more by calcineurin inhibition. These calcineurin dependent genes function in signaling pathways, ion/small molecule transport, cell wall maintenance, vesicular transport, and include many open reading frames of heretofore-unknown function. Three distinct gene classes were defined: 28 genes displayed calcineurin-dependent induction in response to Ca2+ and Na+, 125 showed calcineurin-dependent expression following Ca2+ but not Na+ addition, and 10 were regulated by calcineurin in response to Na+ but not Ca2+. Analysis of crz1D cells established Crz1p as the major effecter of calcineurin-regulated gene expression in yeast. We identified the Crz1p binding site as 5-GNGGC(G/T)CA-3 by in vitro site selection. A similar sequence, 5-GAGGCTG-3, was identified as a common sequence motif in the upstream regions of calcineurin/Crz1p-dependent genes. This finding is consistent with direct regulation of these genes by Crz1p. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
Project description:The Ca2+/calcineurin signaling pathway is a central conduit regulating growth, development, and virulence of fungal pathogens infecting plants and human. We have analyzed global gene expression profiles during Ca2+ treatment in the rice blast fungus, Magnaporthe oryzae. An immunosuppressive drug, FK506, and the knock-out mutant of a transcription factor, MoCRZ1, were included to analyze calcineurin- and/or CRZ1-dependent gene expression, respectively. About 1,400 genes were up or down regulated by Ca2+ treatment, while about 200 genes seemed to be up-regulated in a calcineurin/CRZ1-dependent manner.
Project description:Self-renewal and pluripotency are hallmarks of embryonic stem cells (ESCs). However, signaling pathways triggering their transition from self-renewal to differentiation are not well defined. Here, we report that the calcineurin-NFAT signaling pathway is both necessary and sufficient to switch ESCs from an undifferentiated state to early differentiation.To gain an insight into the function of calcinerin-NFAT signaling in ESC lineage commitment, we examined the repertoire of genes changed after LIF withdrawal alone, LIF withdrawal in the presence of cyclosporine A (CsA), a specific inhibitor of calcinerin and forced expression of active forms of calcineurin (deltaCnA) in the presence of LIF,and identified distinct classes of up and down regulated genes by calcineurin-NFAT signaling in mouse embryonic stem cells.