Phosphoric Monoester Hydrolases (Total 57401 Papers Found)

Interaction with the multi-PDZ protein GRIP is required for the synaptic targeting of AMPA receptors, but the underlying mechanism is unknown. We show that GRIP binds to the liprin-alpha/SYD2 family of proteins that interact with LAR receptor protein tyrosine phosphatases (LAR-RPTPs) and that are implicated in presynaptic development. In neurons, liprin-alpha and LAR-RPTP are enriched at synapses and coimmunoprecipitate with GRIP and AMPA receptors. Dominant-negative constructs that interfere wi ...
The accumulation of free lysine in tobacco seed triggers the stimulation of lysine-ketoglutarate reductase, an enzyme that acts in lysine catabolism. The mechanism of lysine-ketoglutarate reductase stimulation was studied in two different systems: (1) developing seeds of wild-type plants in which the low basal lysine-ketoglutarate reductase activity can be stimulated by the exogenous addition of lysine; and (2) developing seeds of transgenic tobacco plants expressing a bacterial dihydrodipicolin ...
One of the earliest responses to a DNA double-strand break (DSB) is the carboxy-terminal phosphorylation of budding yeast H2A (metazoan histone H2AX) to create gammaH2A (or gammaH2AX). This chromatin modification stretches more than tens of kilobases around the DSB and has been proposed to play numerous roles in break recognition and repair, although it may not be the primary signal for many of these events. Studies suggest that gammaH2A(X) has 2 more direct roles: (i) to recruit cohesin around ...
Accumulating evidence suggests that protein tyrosine phosphorylation-based signaling pathways are under the regulation of reactive oxygen species. Although protein tyrosine phosphatases are directly regulated by reversible oxidation, it is not clear whether protein tyrosine kinases (PTKs) are also directly regulated by reduction/oxidation (redox). In this study we report a mechanism of direct oxidative inactivation specific for the PTKs in the Src and fibroblast growth factor receptor (FGFR) fam ...
Brain reperfusion causes prompt, severe, and prolonged protein synthesis suppression and increased phosphorylation of eukaryotic initiation factor 2alpha [eIF2alpha(P)] in hippocampal CA1 and hilar neurons. The authors hypothesized that eIF2alpha(P) dephosphorylation would lead to recovery of protein synthesis. Here the effects of insulin, which activates phosphatases, were examined by immunostaining for eIF2alpha(P) and autoradiography of in vivo 35S amino acid incorporation. Rats resuscitated ...
Protein tyrosine phosphatases (PTPs) tightly regulate tyrosine phosphorylation essential for cell growth, adhesion, migration, and survival. We performed a mutational analysis of the PTP gene family in cutaneous metastatic melanoma and identified 23 phosphatase genes harboring somatic mutations. Among these, receptor-type tyrosine-protein phosphatase delta (PTPRD) was one of the most highly mutated genes, harboring 17 somatic mutations in 79 samples, a prevalence of 21.5%. Functional evaluation ...
Microcystin-LR (MCYST-LR), a cyclic peptide hepatotoxin, associates with high-molecular-weight, liver cytosolic components. Repetitive cycles of heat denaturation and pronase digestion released 80 +/- 6% of the bound radiolabel from these components, parent toxin (22%), and two biotransformation products, with high-performance liquid chromatography (HPLC) retention times of 6.7 (52%) and 5.6 (13%) min. Both parent and the biotransformed (6.7 min) toxin appeared to be covalently bound to a monome ...
Oocytes from eight inbred strains of mice were screened for the timing of germinal vesicle breakdown (GVB) in vitro. This characteristic varied between strains, reaching most extreme values in oocytes from AKR and BALB/c mice (3.1 and 1.6 h after release from dibutyryl cAMP block, respectively; p < 0.0001). The difference between AKR and BALB/c mice was confirmed in experiments in which GVB was induced in vivo by stimulation with exogenous gonadotrophins. Analysis of the rate of GVB in hybrid ...
Structure of Fly RPTPs As with PTKs, PTPs come in two flavors, cytoplasmic Max-Planck-Institut fü r Entwicklungsbiologie Abteilung Physikalische Biologie and receptor-like, and share the greatest sequence similarity in their phosphatase domains. Cytoplasmic PTPs 72076 Tü bingen Federal Republic of Germany comprise a single phosphatase domain and one or more protein-binding domains, while RPTPs comprise a cyto-In the long-standing mystery of who steers the growth plasmic region containing one o ...
Polyethylene wear debris induces progressive osteolysis by increasing bone degradation and suppressing bone formation. Polyethylene particles inhibit the function of mature osteoblasts, but whether polyethylene particles also interfere with the proliferation and differentiation of osteoprogenitor cells is unknown. In this study, we investigated the effects of ultrahigh molecular weight polyethylene (UHMWPE) particles on the osteogenic activity of primary murine bone marrow osteoprogenitors and M ...
BACKGROUND To determine whether proapoptotic proteins were associated with clinicopathologic heterogeneity and influenced survival in patients with diffuse large B-cell lymphoma (DLBCL), we evaluated patterns of expression of the BCL-2 family member BAD, PP1alpha (the catalytic subunit of PP1 involved in activation of BAD), and apoptosis-inducing factor (AIF). PATIENTS AND METHODS We retrospectively analyzed 46 patients all treated with standard chemotherapy ([CHOP] cyclophosphamide/doxorubici ...
In cultured XD6S tobacco cells, xylanase from Trichoderma viride (TvX) induced the expression of a luciferase reporter gene that was under the control of a GCC box, which is an 11 bp sequence (TAAGAGCCGCC) that is found in the 5'-upstream region of pathogen-responsive defence genes that include genes for class I basic chitinase. TvX-induced biosynthesis of ethylene was not required for the TvX-activated transcription. The TvX-induced, GCC box-mediated transcription of the reporter gene was compl ...
BACKGROUND Infant dura mater plays a critical role in calvarial development. This investigation examines the expression of nitric oxide synthase isoforms in the craniofacial skeleton and the influence of nitric oxide signaling on the growth and differentiation of fetal dural and calvarial bone cells. METHODS Sections of fetal and adult calvaria were evaluated for endothelial and inducible nitric oxide synthase expression by immunohistochemistry. Primary fetal (E18) murine dural cell and calvar ...
Studies suggest that not only is insecticide resistance conferred via multiple gene up-regulation, but it is mediated through the interaction of regulatory factors. However, no regulatory factors in insecticide resistance have yet been identified, and there has been no examination of the regulatory interaction of resistance genes. Our current study generated the first reference transcriptome from the adult house fly and conducted a whole transcriptome analysis for the multiple insecticide resist ...
More than twenty different genetic diseases have been described that are caused by mutations in phosphoinositide metabolizing enzymes, mostly in phosphoinositide phosphatases. Although generally ubiquitously expressed, mutations in these enzymes, which are mainly loss-of-function, result in tissue-restricted clinical manifestations through mechanisms that are not completely understood. Here we analyze selected disorders of phosphoinositide metabolism grouped according to the principle tissue aff ...
Protein phosphatases are the vital regulatory components of various signal transduction pathways in eukaryotes. Signaling pathways triggered during stress and development have been regulated by different classes of protein phosphatases in plants. Recently, genome-wide expressional analysis in Arabidopsis and crop plant such as rice revealed differential expression pattern for several protein phosphatases under different abiotic stresses, in various tissues and at different developmental stages. ...
In protein tyrosine phosphatase 1B (PTP1B), the flexible WPD loop adopts a closed conformation (WPDclosed ) in the active state of PTP1B, bringing the catalytic Asp181 close to the active site pocket, while WPD loop is in an open conformation (WPDopen ) in the inactive state. Previous studies showed that Asp181 may be protonated at physiological pH, and ordered water molecules exist in the active site. In the current study, molecular dynamics simulations are employed at different Asp181 protonat ...
During their differentiation, osteoblasts sequentially express type I collagen, alkaline phosphatase (ALP), and osteocalcin, and then undergo mineral deposition. Among dihydropyridine-type calcium channel blockers, only benidipine stimulated ALP activity of osteoblastic cells derived from neonatal mouse calvaria. To identify the molecular target of benidipine and elucidate the mechanism of action of the drug in osteoblasts, the mouse osteoblastic cell line MC3T3-E1 was used. Benidipine prompted ...
Reversible protein phosphorylation is an important and versatile mechanism by which cells transduce external signals into biological responses. Cellular levels of protein phosphorylation are determined by the balanced actions of both protein kinases and protein phosphatases (PPases). Compared with protein kinases, however, serine/threonine PPases have received less attention. In the present study, the effects of certain insulin secretagogues and intracellular second messengers, known to stimulat ...
Semantic Scholar extracted view of "cDNA cloning of serine/threonine phosphatase catalytic subunits and reversion of the malignant phenotype to the normal phenotype by okadaic acid, a protein phosphatase inhibitor." by M. Nagao et al. ...
Serum total, different isoforms of both alkaline and acid phosphatases, liver function enzymes, calcium, inorganic phosphate, heamatocrit, white blood cells and platelet counts were determined in 50 female patients suffering from breast cancer. The serum total alkaline and total acid phosphatases within the breast cancer group were variable with significant elevation of both enzymes compared with the corresponding control values. The activities of alanine and aspartate transferases were higher t ...
A comparative study of immunohistochemical staining for neuron-specific enolase (NSE), protein-gene product 9.5 (PGP 9.5) and S-100 was made in 71 undifferentiated round cell tumours from 65 children using formalin-fixed tissues and a standard alkaline phosphatase-anti-alkaline phosphatase method. All of 29 neuroblastomas marked for NSE and 27 for PGP 9.5; staining was diffuse and usually strong in all tumour elements, irrespective of the degree of differentiation. Patterns of staining remained ...
AIMS The mammalian soluble epoxide hydrolase (sEH) has both an epoxide hydrolase and a phosphatase domain. The role of sEH hydrolase activity in the metabolism of epoxyeicosatrienoic acids (EETs) and the activation of endothelial nitric oxide synthase (eNOS) in endothelial cells (ECs) has been well defined. However, far less is known about the role of sEH phosphatase activity in eNOS activation. In the present study, we investigated whether the phosphatase domain of sEH was involved in the eNOS ...
We describe a simple, reproducible, discontinuous system for polyacrylamide disc gel-electrophoresis, with which the alkaline phosphatase isoenzymes in human serum can be fractionated. No sample preparation is needed. The isoenzymes are classified according to their electrophoretic mobilities (R-F values) and quantitated by peak area measurements from spectrophotometric scans. The four alkaline phosphatase isoenzymes usually present in normal sera, in order of descending mobilities (and designat ...
The effect of polymer on the retention and the thermal stability of bioactive enzymatic papers was measured using a colorimetric technique quantifying the intensity of the enzyme-substrate product complex. Alkaline phosphatase (ALP) was used as model enzyme. Three water soluble polymers: a cationic polyacrylamide (CPAM), an anionic polyacrylic acid (PAA) and a neutral polyethylene oxide (PEO) were selected as retention aids. The model polymers increased the enzyme adsorption on paper by around 5 ...
For many types of cells, an increase in cell density leads to characteristic changes in intracellular signalling and cell function. It is unknown, however, whether cell density affects the function of T lymphocytes. It is presented here that aggregation of Jurkat T cells, murine thymocytes or human peripheral blood T cells, results in gradual modification of the Lck tyrosine kinase. Within one hour of aggregation, Lck in the detergent-insoluble lipid raft fraction is dephosphorylated mainly at t ...
Vanadium oxoanions are known to have a variety of physiological effects including insulin-like activity, inhibition of phosphotyrosine phosphatases, as well as direct interactions with a variety of cellular proteins, such as microtubules. In this study, vanadate was found to form insoluble complexes with histones, as well as other positively charged proteins, in a concentration dependent fashion. This interaction occurred over a 0.5-10 mM range which corresponds to the concentration range requir ...
BACKGROUND AND PURPOSE Cyclical phosphorylation and dephosphorylation of a key residue within the C-terminal domain of the activated type 5 metabotropic glutamate (mGlu₅) receptor is believed to cause the synchronous, oscillatory changes in inositol 1,4,5-trisphosphate and Ca²⁺ levels observed in a variety of cell types. Here, we have attempted to better define the kinase and phosphatase enzymes involved in this modulation. EXPERIMENTAL APPROACH Ca²⁺ and [³H]inositol phosphate ([³H]I ...
Extracellular signal-regulated kinases (ERKs) have been shown to be activated by opioids and functionally linked to addiction. Morphine-associated changes in ERK activity seem to be the characteristic features of opioid action. In this study, we observed a rapid and severe increase in ERK1/2 activity after a 5 min morphine treatment of HEK-MOR cells (transfected with the rat mu-opioid receptor MOR1) expressing mu-opioid receptor. Cellular adaptations to chronic (72 h) morphine treatment were man ...
Serum alkaline phosphatase (ALP) is detected in soluble-form as a result of translocation from the membrane site by cleavage at the glycosyl-phosphatidylinositol moiety (GPI anchor). It is known that membrane-bound ALP (mALP) can be detected in serum in certain pathological and physiological conditions, and that it can be solubilized in vitro to soluble-ALP (sALP) by phosphatidylinositol-specific phospholipase C (PIPLC), phospholipase D, bile salt, detergent, etc. We observed a marked increase i ...
In immature rat microvessels, endothelial cells and glioma cells, exposure to lead results in an increase in the level of protein kinase C in membranes. In this paper we have extended these studies to human erythrocytes and, in addition, studied the phosphorylation of membrane proteins. A significant increase in the phosphorylation of membrane cytoskeletal proteins of molecular mass 120, 80, 52 and 45 kDa was observed in human erythrocytes treated for 60 min with lead acetate at concentrations g ...
Cdc25 dual specificity phosphatases positively regulate the cell cycle by activating cyclin-dependent kinase/cyclin complexes. Of the three mammalian Cdc25 isoforms, Cdc25A is phosphorylated by genotoxic stress-activated Chk1 or Chk2, which triggers its SCFbeta-TrCP-mediated degradation. However, the roles of Cdc25B and Cdc25C in cell stress checkpoints remain inconclusive. We herein report that c-Jun NH2-terminal kinase (JNK) induces the degradation of Cdc25B. Nongenotoxic stress induced by ani ...
Typical ex vivo bone morphogenetic protein-2 (BMP-2) gene therapy for localized bone formation usually utilizes bone marrow stromal cells as gene delivering cells. Skin fibroblasts, which are abundant and easily obtained, have potential advantages for autologous transplantation, but this application has not been adequately investigated. The purpose of this study was to determine the osteogenetic potential of fibroblasts delivering human BMP-2 (hBMP-2) gene by a retroviral system. The phenotypes ...
The crystal structure of a cold-active alkaline phosphatase from a psychrophile, Shewanella sp. (SCAP), was solved at 2.2 A. A refined model showed a homodimer with six metal-ligand sites. The arrangement of the catalytic residues resembled those of alkaline phosphatases (APs), suggesting that the reaction mechanism of SCAP was fundamentally identical to those of other APs. SCAP had two distinct structural features: (i) a loop with Arg122 that bound to the phosphate moiety of the substrate suffe ...
We have demonstrated that the alpha 2,3 sialyltransferase (alpha 2,3 ST) from C6 cultured glioma cells was inhibited in vivo by W-7 and related Ca2+/Calmodulin (Ca/CaM) antagonists while protein kinase C effectors had no effect. Dephosphorylation of alpha 2,3 ST by the wide specificity alkaline phosphatase led to inactivation indicating that the enzyme is phosphorylated. The serine/threonine protein phosphatase inhibitors okadaic acid and Calyculin A led also to an inhibition of alpha 2,3 ST act ...
We reported previously that in mouse testis calmodulin-dependent protein phosphatase (calcineurin) is localised in the nuclei of round and elongating spermatids (Cell Tissue Res. 1995; 281: 273-81). In this study, we studied the immunohistochemical localisation of calcium/calmodulin-dependent protein kinase (CaM kinase II) using antibodies against CaM kinase IIgamma from chicken gizzard and specific antibodies raised against the amino acid sequence Ileu480-Ala493 of this enzyme, and compared it ...
More than any other organ, the heart is particularly sensitive to gene expression deregulation, often leading in the long run to impaired contractile performances and excessive fibrosis deposition progressing to heart failure. Recent investigations provide evidences that the protein phosphatases (PPs), as their counterpart protein kinases, are important regulators of cardiac physiology and development. Two main groups, the protein serine/threonine phosphatases and the protein tyrosine phosphatas ...
he Cajal body (CB, formerly coiled body) is a prominent nuclear structure, yet its function remains obscure. Now, speculate that the CB is where small nuclear RNAs go for modification. Last year, Kiss's team identified a small guide RNA, U85, that directs both 2'-O-methylation and pseudouridylation of the spliceosomal component U5 snRNA. This year, they've identified six more RNAs, Novel guide RNAs localize to CBs. U87-U92, dubbed small Cajal body–specific RNAs, or scaRNAs. The new scaRNAs res ...
MENK, the endogenous neuropeptide, is suggested to be involved in the regulatory loop between the immune and neuroendocrine systems, with modulation of various functions of cells related to both the innate and adaptive immune systems. Our present research findings show that MENK serves as an immune modulator to the pathway between DCs and CD4+T cells. We studied changes of DCs in key surface molecules, the activity of acid phosphatases (ACPs), the production of IL-12, and the effects on murine C ...
PhosphoSite is a curated, web-based bioinformatics resource dedicated to physiologic sites of protein phosphorylation in human and mouse. PhosphoSite is populated with information derived from published literature as well as high-throughput discovery programs. PhosphoSite provides information about the phosphorylated residue and its surrounding sequence, orthologous sites in other species, location of the site within known domains and motifs, and relevant literature references. Links are also pr ...
The regulation of protein phosphorylation requires coordinated interaction between protein kinases and protein phosphatases (PPs). Recent evidence has shown that the Galphaq-protein-coupled metabotropic glutamate receptor (mGluR) 5 up-regulates phosphorylation of MAPK/ERK1/2. However, signaling mechanisms linking mGluR5 to ERK are poorly understood. In this study, roles of a major serine/threonine PP, PP2A, in this event were evaluated in cultured neurons. We found that the PP1/2A inhibitors oka ...
Vegetative desiccation tolerance is common in bryophytes, although this character has been lost in most vascular plants. The moss Physcomitrella patens survives complete desiccation if treated with abscisic acid (ABA). Group A protein phosphatases type 2C (PP2C) are negative regulators of abscisic acid signalling. Here we show that the elimination of Group A PP2C is sufficient to ensure P. patens survival to full desiccation, without ABA treatment, although its growth is severely hindered. Micro ...
Isocitrate dehydrogenase (IDH) of Escherichia coli is regulated by phosphorylation and dephosphorylation. This phosphorylation cycle controls the flow of isocitrate through the glyoxylate bypass, a pathway which bypasses the CO2 evolving steps of the Krebs' cycle. IDH is phosphorylated at a single serine which resides in its active site. Phosphorylation blocks isocitrate binding, thereby inactivating IDH. The IDH phosphorylation cycle is catalyzed by a bifunctional protein kinase/phosphatase. Th ...
The occurrence and nature of heat-stable placental-type alkaline phosphatase (Pl-ALP) in extracts from a variety of non-malignant human tissues has been investigated using monoclonal antibodies in a sensitive solid-phase enzyme immunoassay. The presence of Pl-ALP was confirmed in testicular, cervical and lung tissue extracts, and trace amounts were also detected in extracts from mammary and ovarian tissue. Evidence is presented that normal testis contains at least two forms of Pl-ALP, the major ...
Protein phosphatase 5 (PP5) is a unique member of the PPP family of serine/threonine phosphatases based on the presence of tetratricopeptide repeat (TPR) domains within its structure. Since its discovery, PP5 has been implicated in wide ranging cellular processes, including MAPK-mediated growth and differentiation, cell cycle arrest and DNA damage repair via the p53 and ATM/ATR pathways, regulation of ion channels via the membrane receptor for atrial natriuretic peptide, the cellular heat shock ...
Two new substrate chromogens for alkaline phosphatase (ALP) detection have been recently synthesized for use in molecular biology research, salmon and magenta phosphate. We show here that these two chromogens have advantageous characteristics for immunocytochemistry as well. Their relatively delicate pink- and magenta-colored products do not mask the colors produced by other staining procedures. In addition, the reaction products of these substrates are insoluble in water, ethanol, and xylene, p ...
Much of the enzymic machinery required for the assembly of cell surface carbohydrates is located in the endoplasmic reticulum (ER) of eukaryotic cells. Structural information on these proteins is limited and the identity of the active polypeptide(s) is generally unknown. This paper describes the synthesis and characteristics of a photoaffinity reagent that can be used to identify and analyse members of the ER glycan assembly apparatus, specifically those glycosyltransferases, nucleotide phosphat ...