TRAIL deficiency and PP2A activation with salmeterol ameliorates egg allergen-driven eosinophilic esophagitis

2016 ◽  
Vol 311 (6) ◽  
pp. G998-G1008 ◽  
Author(s):  
Leon A. Sokulsky ◽  
Adam M. Collison ◽  
Scott Nightingale ◽  
Anna Le Fevre ◽  
Elizabeth Percival ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Eosinophilic Esophagitis ◽  
Protein Phosphatase ◽  
Eosinophilic Inflammation ◽  
Wild Type ◽  
Food Antigen ◽  
Food Antigens ◽  
Phosphatase 2A ◽  
Pp2a Activation

Food antigens are common inflammatory triggers in pediatric eosinophilic esophagitis (EoE). TNF-related apoptosis-inducing ligand (TRAIL) promotes eosinophilic inflammation through the upregulation of the E3 ubiquitin ligase Midline (MID)-1 and subsequent downregulation of protein phosphatase 2A (PP2A), but the role of this pathway in EoE that is experimentally induced by repeated food antigen challenges has not been investigated. Esophageal mucosal biopsies were collected from children with EoE and controls and assessed for TRAIL and MID-1 protein and mRNA transcript levels. Wild-type and TRAIL-deficient (Tnfsf10−/−) mice were administered subcutaneous ovalbumin (OVA) followed by oral OVA challenges. In separate experiments, OVA-challenged mice were intraperitoneally administered salmeterol or dexamethasone. Esophageal biopsies from children with EoE revealed increased levels of TRAIL and MID-1 and reduced PP2A activation compared with controls. Tnfsf10−/− mice were largely protected from esophageal fibrosis, eosinophilic inflammation, and the upregulation of TSLP, IL-5, IL-13, and CCL11 when compared with wild-type mice. Salmeterol administration to wild-type mice with experimental EoE restored PP2A activity and also prevented esophageal eosinophilia, inflammatory cytokine expression, and remodeling, which was comparable to the treatment effect of dexamethasone. TRAIL and PP2A regulate inflammation and fibrosis in experimental EoE, which can be therapeutically modulated by salmeterol.

scholarly journals Protein Phosphatase 2A Activation Dependent Down Regulation of PGC1-Alpha and FOXO1 Phosphorylation with OSU-2S in Human Lymphoma Cells

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3977-3977
Author(s):  
Sohaila Mohamed Khalil ◽  
Swagata Goswami ◽  
Xiaokui Mo ◽  
Natarajan Muthusamy
Keyword(s):  
Protein Expression ◽  
Cell Lines ◽  
Mitochondrial Biogenesis ◽  
Protein Phosphatase ◽  
Lymphoma Cell ◽  
Canine Lymphoma ◽  
Phosphatase 2A ◽  
Human Lymphoma ◽  
Pp2a Activation

Metabolic reprogramming has been recognized to provide survival advantage in cancer cells. Protein phosphatase 2A (PP2A) is a serine/threonine phosphatase that is involved in regulation of multiple cellular pathways including metabolic events. OSU-2S, is a novel PP2A activator that exhibited potent anti-cancerous properties against human and canine lymphoma cell lines and primary human and canine lymphoma patient samples. It has been shown to activate PP2A in Ramos human lymphoma cell line leading to cytotoxicity that is prevented by inhibition of PP2A with okadaic acid (OA). Peroxisome proliferative activated receptor-gamma co-activator 1 (PPARGC1, also known as PGC1a), is a transcriptional co-activator that serves as a positive regulator of mitochondrial biogenesis and respiration, gluconeogenesis as well as many other metabolic processes such as lipid and energy metabolism. FOXO1 is a transcription factor that directly binds to the promoters of PGC1a and gluconeogenic genes involved in activation of gluconeogenesis. Activated PP2A has been shown to directly interact with FOXO1 and dephosphorylate it, leading to its delayed nuclear translocation. Given the role of PP2A in dephosphorylation of pFOX01, a regulator of PGC1a gene transcription, we hypothesized that PP2A activator OSU-2S, will down regulate PGC-1a expression through PP2A dependent FOXO1 regulation. Consistent with this hypothesis OSU-2S treatment inhibited PGC1a mRNA and protein expression in Jeko, OCI-ly18 and OCI-ly19 and raji lymphoma cell lines 24 hours post treatment. OSU-2S mediated downregulation of PGC1a and mitochondria biogenesis genes (NRF1, ERR alpha and TFAM) are dependent on PP2A activation as concentrations of OA that inhibited PP2A activation abrogated OSU-2S which induced up regulation of PGC1a and mitochondria biogenesis genes . To determine if the OSU-2S mediated inhibition of PGC1a expression is associated with its PP2A dependent modulation of phosphoFOXO1(pFOXO1), we tested the effect of OSU-2S on pFOXO1. Treatment of lymphoma cells with OSU-2S induced 60-70% decrease in pFOXO1 compared to vehicle control P =0.0001)], that is correlated with the decrease in PGC1a protein expression. Importantly OA mediated inhibition of PP2A, prevented OSU-2S-induced FOXO1 dephosphorylation. These studies suggest a role of OSU-2S induced modulation of metabolic regulator PGC1a via PP2A dependent dephosphorylation of FOXO1. Importantly, OSU-2S-induced PGC1a reduction resulted in decreased mitochondrial biogenesis as evidenced by ~43 % decrease in mitochondrial mass and ATP generation that led to reduced energy production as determined by Nonyl Acridine Orange dye staining followed by flow cytometry analysis. Interestingly, OSU-2S decreased expression of genes involved in mitochondrial biogenesis including NRF1a, ERR1a and TFAM by 75, 65 and 60% respectively P<0.0001. Ongoing mechanistic studies are aimed to define the molecular basis of OSU-2S induced transcriptional regulation of PGC1a and other genes involved in mitochondrial biogenesis in human lymphoma cell lines and primary cells. (This work was supported by NIH-R01 CA197844-02. SMK is a recipient of Egyptian Cultural and Educational Bureau (ECEB) Award). SG is a recipient of Pelotonia Graduate Fellowship) Keywords: PGC1- alpha, OSU-2S, PP2A, FOXO1, metabolism, lymphoma Disclosures Muthusamy: Ohio State University: Patents & Royalties: OSU-2S.

scholarly journals The Role of Arg13 in Protein Phosphatase M tPphA from Thermosynechococcus elongatus

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jiyong Su ◽  
Karl Forchhammer
Keyword(s):  
Amino Acid ◽  
Protein Phosphatase ◽  
Arginine Residue ◽  
Side Chain ◽  
Wild Type ◽  
Catalytic Center ◽  
Nitrophenyl Phosphate ◽  
Reduced Activity ◽  
Amino Acid Variants

A highly conserved arginine residue is close to the catalytic center of PPM/PP2C-type protein phosphatases. Different crystal structures of PPM/PP2C homologues revealed that the guanidinium side chain of this arginine residue can adopt variable conformations and may bind ligands, suggesting an important role of this residue during catalysis. In this paper, we randomly mutated Arginine 13 of tPphA, a PPM/PP2C-type phosphatase from Thermosynechococcus elongatus, and obtained 18 different amino acid variants. The generated variants were tested towards p-nitrophenyl phosphate and various phosphopeptides. Towards p-nitrophenyl phosphate as substrate, twelve variants showed 3–7 times higher Km values than wild-type tPphA and four variants (R13D, R13F, R13L, and R13W) completely lost activity. Strikingly, these variants were still able to dephosphorylate phosphopeptides, although with strongly reduced activity. The specific inability of some Arg-13 variants to hydrolyze p-nitrophenyl phosphate highlights the importance of additional substrate interactions apart from the substrate phosphate for catalysis. The properties of the R13 variants indicate that this residue assists in substrate binding.

scholarly journals Loss of a Protein Phosphatase 2A Regulatory Subunit (Cdc55p) Elicits Improper Regulation of Swe1p Degradation

2000 ◽  
Vol 20 (21) ◽  
pp. 8143-8156 ◽  
Author(s):  
Haifeng Yang ◽  
Wei Jiang ◽  
Matthew Gentry ◽  
Richard L. Hallberg
Keyword(s):  
Phosphatase Activity ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Cell Types ◽  
Regulatory Subunit ◽  
Cyclin Dependent Kinase ◽  
Wild Type ◽  
Phosphatase 2A

ABSTRACT CDC55 encodes a Saccharomyces cerevisiaeprotein phosphatase 2A (PP2A) regulatory subunit.cdc55-null cells growing at low temperature exhibit a failure of cytokinesis and produce abnormally elongated buds, butcdc55-null cells producing the cyclin-dependent kinase Cdc28-Y19F, which is unable to be inhibited by Y19 phosphorylation, show a loss of the abnormal morphology. Furthermore,cdc55-null cells exhibit a hyperphosphorylation of Y19. For these reasons, we have examined in wild-type and cdc55-null cells the levels and activities of the kinase (Swe1p) and phosphatase (Mih1p) that normally regulate the extent of Cdc28 Y19 phosphorylation. We find that Mih1p levels are comparable in the two strains, and an estimate of the in vivo and in vitro phosphatase activity of this enzyme in the two cell types indicates no marked differences. By contrast, while Swe1p levels are similar in unsynchronized and S-phase-arrested wild-type and cdc55-null cells, Swe1 kinase is found at elevated levels in mitosis-arrestedcdc55-null cells. This excess Swe1p incdc55-null cells is the result of ectopic stabilization of this protein during G2 and M, thereby accounting for the accumulation of Swe1p in mitosis-arrested cells. We also present evidence indicating that, in cdc55-null cells, misregulated PP2A phosphatase activity is the cause of both the ectopic stabilization of Swe1p and the production of the morphologically abnormal phenotype.

2214 Role of protein phosphatase 2A in hippocampal long-term potentiation

1997 ◽  
Vol 28 ◽  
pp. S254
Author(s):  
Kohji Fukunaga ◽  
Dominique Muller ◽  
Masao Ohmitsu ◽  
Eishichi Miyamoto
Keyword(s):  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Long Term Potentiation ◽  
Term Potentiation ◽  
Phosphatase 2A

scholarly journals Role of Protein Phosphatase 2A in Regulating the Visual Signaling in Drosophila

2008 ◽  
Vol 28 (6) ◽  
pp. 1444-1451 ◽  
Author(s):  
N. Wang ◽  
H.-T. Leung ◽  
W. L. Pak ◽  
Y. T. Carl ◽  
B. E. Wadzinski ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Visual Signaling ◽  
Phosphatase 2A

scholarly journals Protein Phosphatase 2A Stabilizes Human Securin, Whose Phosphorylated Forms Are Degraded via the SCF Ubiquitin Ligase

2006 ◽  
Vol 26 (11) ◽  
pp. 4017-4027 ◽  
Author(s):  
Ana M. Gil-Bernabé ◽  
Francisco Romero ◽  
M. Cristina Limón-Mortés ◽  
María Tortolero
Keyword(s):  
Ubiquitin Ligase ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Anaphase Promoting Complex ◽  
Anaphase Onset ◽  
Chromatid Segregation ◽  
Phosphatase 2A ◽  
F Box Protein

ABSTRACT Sister chromatid segregation is triggered at the metaphase-to-anaphase transition by the activation of the protease separase. For most of the cell cycle, separase activity is kept in check by its association with the inhibitory chaperone securin. Activation of separase occurs at anaphase onset, when securin is targeted for destruction by the anaphase-promoting complex or cyclosome E3 ubiquitin protein ligase. This results in the release of the cohesins from chromosomes, which in turn allows the segregation of sister chromatids to opposite spindle poles. Here we show that human securin (hSecurin) forms a complex with enzymatically active protein phosphatase 2A (PP2A) and that it is a substrate of the phosphatase, both in vitro and in vivo. Treatment of cells with okadaic acid, a potent inhibitor of PP2A, results in various hyperphosphorylated forms of hSecurin which are extremely unstable, due to the action of the Skp1/Cul1/F-box protein complex ubiquitin ligase. We propose that PP2A regulates hSecurin levels by counteracting its phosphorylation, which promotes its degradation. Misregulation of this process may lead to the formation of tumors, in which overproduction of hSecurin is often observed.

scholarly journals Role of Protein Phosphatase 2A in mGluR5-regulated MEK/ERK Phosphorylation in Neurons

2005 ◽  
Vol 280 (13) ◽  
pp. 12602-12610 ◽  
Author(s):  
Limin Mao ◽  
Lu Yang ◽  
Anish Arora ◽  
Eun Sang Choe ◽  
Guochi Zhang ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Erk Phosphorylation ◽  
Phosphatase 2A

The role of subunit B’ of protein phosphatase 2A in pathogenesis of Heterodera schachtii on Arabidopsis thaliana roots

2016 ◽  
Vol 33 ◽  
pp. S157
Author(s):  
Dominik Kanigowski ◽  
Mateusz Matuszkiewicz ◽  
Joanna Dąbrowska ◽  
Anna Barczak ◽  
Marcin Filipecki
Keyword(s):  
Arabidopsis Thaliana ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Heterodera Schachtii ◽  
Phosphatase 2A ◽  
Subunit B
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