Deletion of conserved protein phosphatases reverses defects associated with mitochondrial DNA damage in Saccharomyces cerevisiae
Ontology highlight
ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
SUBMITTER: Cory Dunn
PROVIDER: E-GEOD-52242 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Mitochondrial biogenesis is regulated by signaling pathways sensitive to extracellular conditions and to the internal environment of the cell. We found that deletion of protein phosphatase 2A (PP2A) or of protein phosphatase 6 (PP6) diminishes the nuclear transcriptional response associated with mtDNA damage.
2013-12-23 | GSE52242 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE38565: The yeast PP2A-CDC55 phosphatase regulates the transcriptional response to hyperosmolarity stress by regulating Msn2 and Msn4 [Time course 1] GSE42033: The yeast PP2A-CDC55 phosphatase regulates the transcriptional response to hyperosmolarity stress by regulating Msn2 and Msn4 [Time course 2] Refer to individual Series
2012-11-06 | E-GEOD-42034 | biostudies-arrayexpress
Project description:Damage to the mitochondrial genome (mtDNA) severely affects the cell and causes disease. Mutations to mtDNA also accumulate throughout the lifespan of many organisms and may be a proximal cause of aging. There is no effective treatment for ailments caused by mtDNA mutation. Since mitochondrial function and biogenesis are controlled by the nutrient environment of the cell, it is possible that perturbation of conserved, nutrient-sensing pathways may successfully treat mitochondrial disease. Experiments using the tractable eukaryote Saccharomyces cerevisiae allow us to investigate the connection between nutrient-sensing and mitochondrial function. We have focused our current studies on the protein kinase A (PKA) pathway, which controls S. cerevisiae behavior according to glucose availability. We found that reduced PKA signaling can lead, in a background-dependent manner, to improved fitness after mtDNA loss. Specifically, over-expression of the cyclic AMP phosphodiesterase Pde2p, removal of PKA isoform Tpk3p, or ablation of other proteins promoting PKA activity leads to improved proliferation of cells deleted of the mitochondrial genome. Over-expression of Pde2p also suppresses the inviability of several mutants that normally cannot survive mtDNA loss. Moreover, Pde2p over-expression diminishes the nuclear transcriptional response to mtDNA damage, further supporting the idea that glucose sensation is harmful for cells lacking the mitochondrial genome. These findings are heavily dependent upon yeast genetic background. Interestingly, robust import of mitochondrial polytopic membrane proteins may be required in order for cells with no mtDNA to receive the full benefits of PKA reduction. Our findings support the idea that perturbation of nutrient-sensing pathways, and specifically the sensation of glucose, may benefit cells with dysfunctional mitochondria. Four experimental conditions were used: BY4743 (WT) cells containing empty pRS426 vector and containing mtDNA because EtBr was not used, BY4743 (WT) cells containing empty pRS426 vector and lacking mtDNA after 24 hours of treatment with 25 µg/ml ethidium bromide, BY4743 (WT) cells overexpressing TIP41 from plasmid pRS426 and lacking mtDNA after 24 hours of treatment with 25 µg/ml ethidium bromide, and BY4743 (WT) cells overexpressing PDE2 from plasmid pRS426 and lacking mtDNA after 24 hours of treatment with 25 µg/ml ethidium bromide. Two replicates were performed for each sample type.
2015-08-07 | E-GEOD-71252 | biostudies-arrayexpress
Project description:Phosphatase PP2A expression level is positively correlated to the clinical severity of systemic lupus erythematosus (SLE) and IL17A cytokine overproduction, indicating a potential role of PP2A in controlling TH17 differentiation and inflammation. By generating a mouse strain with the ablation of the catalytic subunit α of PP2A in peripheral mature T cells (PP2A cKO), we provide evidence here that PP2A complex is essential in TH17 differentiation. Hence, PP2A cKO mice exhibited a selective reduction of TH17 cell numbers and an attenuated disease severity in an experimental autoimmune encephalomyelitis (EAE) model. Importantly, PP2A deficiency ablated c-terminal phosphorylation of SMAD2 whereas increased c-terminal phosphorylation of SMAD3. Through direct binding to and regulating the activity of RORγt, the phosphorylational changes of these R-SMADs subsequently reduced Il17a transcription. Finally, PP2A inhibitors recapitulated the phenotype of PP2A cKO mice, i.e., inhibiting TH17 differentiation and protecting mice from EAE. Together, the current study proves that phosphatase PP2A is essential for TH17 differentiation, and inhibition of PP2A could be a possible therapeutic approach for the controlling of TH17-driven autoimmune diseases.
2018-09-13 | GSE119836 | GEO
Project description:Studying whether removal of base-excision repair from mitochondria will result into increase in mitochondrial DNA (mtDNA) mutation load. The endogenous genes of OGG1 and MUTYH DNA glycosylases were modified to lack the genomic region encoding for the predicted mitochondrial targeting sequence. The mouse lines used: A mouse line that lacks the region encoding for the mitochondrial targeting sequence (L2 to W23) of OGG1 (Ogg1 dMTS mice). A mouse line that lacks the region encoding the mitochondrial targeting sequence (K2 to P33) of MUTYH (Mutyh dMTS mice). To accumulate mutations to the mitochondrial DNA these mice were bred double homozygous Mutyh dMTS x Ogg1 dMTS mice as a maternal lineage for five consecutive generations and mitochondrial DNA from liver was extracted from the offspring and sequenced with Illumina. OGG1 and MUTYH are involved in repair of 8-oxo-dG from DNA. 8-oxo-dG can be a mutagenic lesion because some DNA repair polymerases are known to erroneously incorporate adenosine opposite to 8-oxo-dG during replication leading to GC>TA transversion mutations.
2018-07-13 | E-MTAB-6532 | biostudies-arrayexpress
Project description:To study whether increase in mitochondrial oxidative stress (SOD2 removal) and decrease in mitochondrial DNA repair (Ogg1 dMTS) results into increase in mitochondrial DNA mutation load. Oxidative stress has been suggested to induce mutations in mtDNA. To verify this, we extracted and sequenced (Illumina) mitochondrial DNA from heart Sod2 knockout animals that were also deficient for mitochondrial base-excision repair. The repair deficiency was induced by removing the genomic region encoding for the predicted mitochondrial targeting sequence from endogenous OGG1 (L2 to W23) called Ogg1 dMTS mice, thus excluding the protein from mitochondria. OGG1 is a DNA glycosylase that recognizes and repairs 8-oxo-dG damage from DNA. Oxidative stress can induce 8-oxo-dG lesions, thus we removed the mitochondrial matrix localized superoxide dismutase (SOD2) from these mice to increase the level of oxidative stress. 8-oxo-dG lesion can be mutagenic because some DNA repair polymerases are known to erroneously incorporate adenosine opposite to 8-oxo-dG during replication leading to GC>TA transversion mutations.
2018-07-13 | E-MTAB-6533 | biostudies-arrayexpress
Project description:The yeast PP2A-Cdc55 Serine/Threonine phosphatase regulates transcription under certain conditions. It is required for full activation of the environmental stress response mediated by the transcription factors Msn2 and Msn4. PP2A-Cdc55 contributes to sustained nuclear accumulation of Msn2 and Msn4 and extended chromatin recruitment under stress conditions such as hyperosmolarity stress. Transcript profiles of Msn2 and Msn4 double mutants are similar to cdc55 and the corresponding triple mutants. This argues for a Msn2/4 specific function of PP2A-Cdc55. Time course of 10 20 and 30 minutes hyperosmolarity treated yeast cells of wild type (W303), msn2msn4, cdc55, msn2msn5cdc55 genetic background.
2012-06-07 | E-GEOD-38565 | biostudies-arrayexpress
Project description:As a serine/threonine phosphatase, protein phosphatase 2A (PP2A) is essential in numerous physiological processes. Our previously study confirmed PP2A dysfunction can cause azoospermia by generating catalytic subunit of PP2A (Ppp2ca) conditional knockout (CKO) in C57BL/6J mice. Here, we further explored the possible mechanisms by focusing on meiosis initiation and spermatogenesis. The deficiency of Ppp2ca in germ cells conspicuously disturbed spermatogonial differentiation and lead to pachytene arrest, accompanied by defects in programmed double-strand break (DSB) repair and meiotic sex chromosome inactivation (MSCI). Furthermore, Ppp2ca-deficient spermatocytes exhibited abnormal agglutination and cohesion complex degradation of chromosome, probably contributing to pachytene arrest. Our study demonstrates the irreplaceable role of PP2A in spermatogenesis and provide more evidences on azoospermia etiology.
2021-12-01 | GSE181132 | GEO
Project description:Protein phosphatase 2A (PP2A), a serine/threonine phosphatase, has been shown to control T cell function. We found that in vitro activated B cells and B cells from various lupus-prone mice and patients with systemic lupus erythematosus display increased PP2A activity. To understand the contribution of PP2A to B cell function, we generated a Cd19CrePpp2r1aflox/flox (flox/flox) mouse which lacks functional PP2A only in B cells. Flox/flox mice displayed reduced spontaneous germinal center formation and decreased responses to T-dependent and T-independent antigens while their B cells responded poorly in vitro to stimulation with an anti-CD40 antibody or CpG in the presence of IL-4. Transcriptome and metabolome studies revealed altered NAD and purine/pyrimidine metabolism and increased expression of purine nucleoside phosphorylase in PP2A-deficient B cells. Our results demonstrate that PP2A is required for optimal B cell function and may contribute to increased B cell activity in systemic autoimmunity.
2020-02-04 | GSE144700 | GEO
Project description:We evaluated the effects of suppressing MAP4K4 on transcriptome and YAP1 pathway based on the observation that partial suppression of MAP4K4 leads to transformation through activation of YAP1. Mutations and deletions involving subunits of the serine-threonine phosphatase PP2A occur in a broad range of human cancers, and partial loss of PP2A function contributes to cell transformation. In particular, displacement of regulatory B subunits by the viral oncoprotein SV40 small-t antigen (ST) or mutation or deletion of PP2A subunits alters the abundance and types of PP2A complexes in cells and induces cell transformation in human cells. Here we show that ST not only displaces common PP2A B subunits but also promotes PP2A A-C subunit interactions with a set of alternative B subunits (B’’’, striatins) that are components of the Striatin-interacting phosphatase and kinase (STRIPAK) complex. We found that members of the STRIPAK complex are required for ST-PP2A induced cell transformation. PP2A interacts with and dephosphorylates the STRIPAK-associated kinase MAP4K4, which induces cell transformation in part through the regulation of the Hippo pathway effector YAP1. These observations identify an unanticipated role of MAP4K4 in transformation and show that the STRIPAK complex plays a key role in defining PP2A specificity and activity.
2019-12-01 | GSE118272 | GEO