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T Katada

Publications and source records attributed to T Katada.

At least 73 records · Page 4Linked to original sources
PubMed1996

Induction of CD38/NADase and its monoclonal antibody-induced tyrosine phosphorylation in human leukemia cell lines.

We previously reported that CD38 characterized as an ecto-enzyme of NAD+ glycohydrolase (NADase) was specifically induced by retinoic acid (RA) in human promyelocytic leukemia HL-60 cells and that anti-CD38 monoclonal antibody (mAb) induced tyrosine phosphorylation of cellular proteins in the RA-differentiated cells. In the present study, we found that CD38/NADase was induced in human monocytic leukemia THP-1 cells not only by RA but also by dibutyryl cAMP, which had no effect on the induction of CD38 in HL-60 cells. Similarly in the RA-differentiated HL-60 cells, tyrosine phosphorylation by anti-CD38 mAb was also observed in the CD38-expressing THP-1 cells, regardless of whether CD38 was induced by RA or dibutyryl cAMP. Such tyrosine phosphorylation was, however, not observed in human lymphoblastic leukemia Jurkat cells which had been treated by RA to produce CD38. Thus, the induction of CD38/NADase appeared to be not limited for RA-dependent differentiation and not always linked to protein-tyrosine phosphorylation in human leukemic cell lines.

ADP-ribosyl Cyclase↗
PubMed1996

Focal adhesion kinase (p125FAK) and paxillin are substrates for sphingomyelinase-induced tyrosine phosphorylation in Swiss 3T3 fibroblasts.

We examined the effect of sphingomyelinase on tyrosine phosphorylation of intracellular proteins in mouse Swiss 3T3 fibroblasts. Incubation of the cells with bacterial sphingomyelinase resulted in the elevation of tyrosine phosphorylation of multiple cellular proteins of 190, 130, 120, 97 and 70 kDa within minutes. The 120 and 70 kDa tyrosine-phosphorylated peptides were identified as p125 focal adhesion kinase (p125FAK) and paxillin respectively by the use of specific antibodies against the proteins. Tyrosine kinase activity associated with anti-p125FAK immunoprecipitate was stimulated by incubation of cells with sphingomyelinase. Cytochalasin D, which selectively disrupts the network of actin filaments, inhibited sphingomyelinase-induced tyrosine phosphorylation of p125FAK and elevation of tyrosine kinase activity in the anti-p125FAK immunoprecipitates. Sphingomyelinase-induced phosphorylation of p125FAK was not inhibited by wortmannin, an inhibitor of phosphatidylinositol 3-kinase. This was in sharp contrast with a wortmannin-sensitive phosphorylation of p125FAK observed in platelet-derived growth factor (PGDF)-stimulated cells. Thus hydrolysis of sphingomyelin is considered to regulate the tyrosine kinase cascade including p125FAK and paxillin by a mechanism distinct from PDGF.

3T3 Cells↗
PubMed1996

Inositol 1,4,5-trisphosphate-gated calcium transport through plasma membranes in nerve terminals.

We developed new biochemical approaches to demonstrate the presence of inositol 1,4,5-triphosphate (InsP3)-gated calcium channels in presynaptic plasma membranes (SPM) and their involvement in the presynaptic receptor-mediated Ca2+ influx into nerve terminals. In perfusion experiments using SPM vesicles preloaded with 45Ca2+, InsP3 elicited the release of 45CA2+ into perfusates in a saturable manner. The InsP3- evoked 45Ca2+ release from resealed SPM vesicles was more potent than that from resealed vesicles using any other subcellular fractions. Here we also report the involvement of InsP3-gated mechanisms in the presynaptic receptor-mediated Ca2+ influx into synaptosomes (nerve terminals) by use of such resealed vesicles reconstituted with purified Gi1.

Adenosine Triphosphate↗
PubMed1996

Activation of phosphatidylinositol 3-kinase by concanavalin A through dual signaling pathways, G-protein-coupled and phosphotyrosine-related, and an essential role of the G-protein-coupled signals for the lectin-induced respiratory burst in human monocytic THP-1 cells.

Stimulation of monocytic THP-1 cells by a lectin, concanavalin A (Con A), resulted in protein-tyrosine phosphorylation and association of some of the thus phosphorylated proteins with the 85 kDa regulatory subunit of PtdIns 3-kinase. Both actions of Con A were not inhibited by wortmannin, a PtdIns 3-kinase inhibitor, or by prior exposure of cells to pertussis toxin which uncouples certain G-proteins from receptors. The binding of PtdIns 3-kinase to the tyrosine-phosphorylated proteins increased upon Con A stimulation; there was a marked increase in the enzymic activity in the anti-phosphotyrosine immuno-precipitates from Con A-treated cells. The increase was abolished by wortmannin but not affected by pertussis toxin. The incorporation of 32P into PtdInsP3 also increased during incubation of [32P]P(i)-prelabelled cells with Con A, reflecting activation of whole-cell PtdIns 3-kinase which could not be accounted for solely by the increase in the phosphotyrosine-bound enzyme activity from the following aspects: (1) different concentration dependencies for Con A; and (2) almost total susceptibility of the incorporation to pertussis toxin. This notion appears to be supported by different time courses between increases in PtdInsP3 production and the phosphotyrosine-bound activity. The susceptibility to the toxin may reflect involvement of the toxin-sensitive G-proteins. In contrast, insulin-induced increases in PtdInsP3 production, as well as increases in phosphotyrosine-bound PtdIns 3-kinase activity, were blocked by wortmannin, but never affected by prior exposure of cells to pertussis toxin, excluding a possible involvement of G-proteins in the insulin-induced activation. Con-A-induced O2- production was almost inhibited by either pertussis toxin or wortmannin. These results suggest that oligomerization of cell-surface glycoproteins with Con A gives rise to activation of G-protein(s) and certain tyrosine kinase(s), both of which were responsible for PtdIns 3-kinase activation; the G-protein-mediated activation led to the respiratory burst.

Amino Acid Sequence↗
PubMed1996

Specific association of phosphatidylinositol 3-kinase with the protooncogene product Cbl in Fc gamma receptor signaling.

A tyrosine-phosphorylated protein with a molecular mass of 115 kDa was reported to be tightly associated with the p85 regulatory subunit of phosphatidylinositol (PI) 3-kinase, when the enzyme was essentially activated upon ligand engagement of Fc gamma receptors (Fc gamma R) leading to engulfment of IgG-coated erythrocytes by phagocytes [Ninomiya et al. (1994) J. Biol. Chem. 269, 22732-22737]. Here, the 115-kDa protein is identified as the product of human c-cbl protooncogene. Cross-linking of Fc gamma RII on the surface of THP-1 cells triggered (a) prominent tyrosine phosphorylation of Cbl, (b) activation of PI 3-kinase that was immunoprecipitated with the anti-Cbl or the anti-phosphotyrosine antibody, and (c) specific association of Cbl with p85. Thus, Cbl functions in phagocytes as a result of its association with PI 3-kinase in response to Fc gamma R ligation.

Antibodies, Monoclonal↗
PubMed1996

Augmentation by calmodulin of ADP-ribosylation factor-stimulated phospholipase D activity in permeabilized rabbit peritoneal neutrophils.

Activation of the membrane-bound phospholipase D (PLD) requires cytosolic factor(s), and ADP-ribosylation factor (ARF) has been identified as a cytosolic PLD activator. In the present study, we demonstrate that calmodulin (CaM) and ARF are both involved in PLD activation in rabbit peritoneal neutrophils. The PLD activity of streptolysin O-permeabilized, cytosol-depleted rabbit neutrophils was significantly enhanced when the permeabilized cells were reconstituted with bovine brain cytosol in the presence of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S), whereas there was little activation of the enzyme in the absence of cytosol. The GTP gamma S-stimulated PLD activity in the presence of cytosol was augmented on increasing the concentration of free Ca2+. The PLD activity stimulated by GTP gamma S and Ca2+ in this system was inhibited by the calmodulin inhibitor W-7. These findings suggest that CaM plays a role as a cytosolic PLD activator. Moreover, highly purified CaM alone, as well as partially purified ARF alone, promoted a slight stimulation of the PLD activity in permeabilized neutrophils. Interestingly, ARF-stimulated PLD activity was augmented by CaM in the presence of GTP gamma S and Ca2+. This augmentation was again inhibited by W-7, as well as by the structurally unrelated CaM inhibitor trifluoperazine. These data imply that CaM stimulates the PLD activity of rabbit neutrophils in concert with ARF.

ADP-Ribosylation Factors↗
PubMed1996

Tyrosine phosphorylation of the c-cbl proto-oncogene product mediated by cell surface antigen CD38 in HL-60 cells.

The human cell surface antigen CD38 is a 46-kDa type II transmembrane glycoprotein with a short N-terminal cytoplasmic domain and a long Cys-rich C-terminal extracellular one. We demonstrated previously that the extracellular domain of CD38 has NAD+ glycohydrolase (NADase) activity and that the ecto-form NADase activity induced in HL-60 cells during cell differentiation by retinoic acid is due to CD38. In the present study, we investigated the intracellular signaling mediated by CD38 in retinoic acid-differentiated HL-60 cells with an anti-CD38 monoclonal antibody. The addition of anti-CD38 monoclonal antibody to the cells induced rapid tyrosine phosphorylation of the cellular proteins with molecular weights of 120,000, 87,000, and 77,000. An increase in tyrosine kinase activity in the anti-phosphotyrosine immunoprecipitates of the cells was also observed after the addition of anti-CD38 monoclonal antibody. Moreover, one of the prominent tyrosine-phosphorylated proteins stimulated by the anti-CD38 monoclonal antibody was identified as the c-cbl proto-oncogene product, p120c-cbl. These results indicated that tyrosine phosphorylation of cellular proteins, including p120c-cbl, is possibly involved in transmembrane signaling mediated by CD38.

ADP-ribosyl Cyclase↗
PubMed1996

GTP-binding protein activation underlies LTP induction by mast cell degranulating peptide.

Mast cell degranulating peptide (MCD) induces long-term potentiation (LTP) in the CA1 region of the hippocampus. MCD has been shown to bind to a voltage-dependent A-type potassium channel with high-affinity (less than 1 nM). However, the concentration necessary to induce LTP is more than 500 nM, suggesting that some other functions of MCD are also fundamental to LTP induction. The concentration of MCD required for LTP induction was greatly reduced by preactivating G proteins. This fact suggests that G protein activation by MCD also plays an important role in LTP induction. MCD-binding proteins were purified from rat brain. G proteins were found to exist in a non-denatured state in this affinity-purified fraction. When reconstituted into a planar lipid bilayer membrane, a potassium-selective and voltage-dependent current could be observed. This channel was blocked by MCD at a high concentration equal to the effective concentration for G protein activation. Addition of GTP-gamma-S significantly blocked the reconstituted current. Thus, we identified a pathway for LTP induction by MCD in which high concentrations of MCD activate G protein which in turns leads to blocking of a potassium channel.

Adenosine Diphosphate Ribose↗
PubMed1996

A subtype of kappa-opioid receptor mediates inhibition of high-affinity GTPase inherent in Gi1 in guinea pig cerebellar membranes.

The kappa-opioid receptor agonists including U-50,488H and dynorphin A (1-17) in ranges of 0.1-100 nM inhibited the hydrolysis of GTP to GDP (P(i) release) inherent in GTP-binding proteins (G proteins) in guinea pig cerebellar membranes. U-50,488H inhibited only high-affinity GTPase activity, not low-affinity activity. The action of this agonist was found to be biphasic, and there was no inhibition at concentrations > 1 microM. The inhibition was abolished by pretreatment with preactivated pertussis toxin (PTX) at concentrations > 1 micrograms/ml but not with preactivated cholera toxin (30 micrograms/ml). Similar blockade of kappa-receptor-mediated inhibition was also observed when membranes were pretreated with a low concentration (8 microM) of N-ethylmaleimide (NEM) at low temperature (4 degrees C), which alkylates the cysteine residue to be ADP-ribosylated by PTX; but this treatment caused no significant change in kappa-agonist binding. When purified Gi1, but not G(o), was reconstituted into membranes pretreated with NEM, the kappa-receptor-mediated inhibition was recovered. These findings suggest that a subtype of kappa-opioid receptor is coupled to inhibition of intrinsic activity of Gi1.

Animals↗
PubMed1996

Partially purified RhoA-stimulated phospholipase D activity specifically binds to phosphatidylinositol 4,5-bisphosphate.

Phosphatidylinositol 4,5-bisphosphate (PIP2) is absolutely required for the ADP-ribosylation factor-stimulated phospholipase D (PLD) activity. In the present study, partially purified rat brain PLD was found to be activated by another PLD activator, RhoA, when PIP2, but not other acidic phospholipids, was included in vesicles comprising phosphatidylethanolamine (PE) and the PLD substrate phosphatidyicholine (PC) (PE/PC vesicles), demonstrating the absolute requirement of PIP2 for the RhoA-stimulated PLD activation, too. It is interesting that the RhoA-dependent PLD activity in the partially purified preparation was drastically decreased after the preparation was incubated with and separated from PE/PC vesicles containing PIP2. The PLD activity was extracted by higher concentrations of NaCl from the vesicles containing PIP2 that were incubated with and then separated from the partially purified PLD preparation. These results demonstrate that RhoA-dependent PLD binds to PE/PC vesicles with PIP2. The degree of binding of the RhoA-dependent PLD activity to the vesicles was totally dependent on the amount of PIP2 in the vesicles and correlated well with the extent of the enzyme activation. Further-more, it was found that a recombinant peptide of the pleckstrin homology domain of beta-adrenergic receptor kinase fused to glutathione S-transferase, which specifically binds to PIP2, inhibited the PIP2-stimulated, RhoA-dependent PLD activity in a concentration-dependent manner. From these results, it is concluded that in vitro rat brain PLD translocates to the vesicles containing PIP2, owing to its specific interaction with PIP2, to access its substrate PC, thereby catalyzing the hydrolysis of PC. PLD appears to localize exclusively on plasma membranes of cells and tissues. An aminoglycoside, neomycin, that has high affinity for PIP2 effectively extracted the RhoA-dependent PLD activity from rat brain membranes. This indicates that PIP2 serves as an anchor to localize PLD on plasma membranes in vivo.

ADP-Ribosylation Factors↗
PubMed1996

[The evaluation of three dimensional image distortion of helical scanning CT].

We developed a computer algorithm to simulate distortion in the three-dimensional (3D) displays obtained by helical scanning. The algorithm constitutes calculation of the image profile in the longitudinal direction, which is assumed to be a convolution of the object function with the slice sensitivity profile (SSP) of helical scanning. Experiments were performed to examine the algorithm for its validity with the use of a K2HPO4 phantom. Simulated results and measurements was in a good agreement. The distortion was investigated by the computer simulation. The model simulated was a high density object (Ol) surrounded by low density tissue (Os). The helical interpolation used was 360-degree linear interpolation. Two parameters were defined: delta Lz, which is the difference in length between the 3D image and the actual object Ol in the longitudinal direction, and the cut level index (CLI), which is defined as CLI = (Cut Level CT Number-CT Number of Os)/(CT Number of OI-CT Number of Os). We found that magnitude of delta Lz increased depending on the table feed distance per 360-degree scan (Dt). When Ol was twice as long as Dt, delta Lz directly depended on CLI, but was independent of Ol length. When Ol length was longer than Dt, delta Lz was shown to be 0 at CLI not equal to 0.5 at every Dt. When Ol was shorter than Dt, delta Lz decreased remarkably depending on the length of Ol in higher CLI. The simulations, with the use of a newly developed algorithm, were demonstrated to be useful for evaluating the amount of distortion and for better understanding the characteristics of 3D displays of helical scanning.

Algorithms↗
PubMed1995

Radiolabeling of catalytic subunits of PI 3-kinases with 17 beta-hydroxy-16 alpha(-)[125I]iodowortmannin: identification of the G beta gamma-sensitive isoform as a complex composed of 46-kDa and 100-kDa subunits.

A fungal metabolite, wortmannin, is a potent inhibitor of phosphatidylinositol (PI) 3-kinases. In the present study, we prepared a radiolabeled derivative of wortmannin, 17 beta-hydroxy-16 alpha(-)[125I]iodowortmannin. The compound bound tightly to a 110-kDa subunit in the previously identified isoform of PI 3-kinase (p85/p110), and also to a 100-kDa peptide in a partially purified preparation of another isoform of PI 3-kinase whose activity was markedly stimulated by the beta gamma subunits of GTP-binding proteins (G beta gamma). The binding to both peptides was inhibited by non-radiolabeled wortmannin and also by LY294002, another inhibitor of PI 3-kinases. An antibody against p85 recognized a 46-kDa peptide in the G beta gamma-sensitive isozyme and precipitated the 100-kDa peptide specifically labeled with 17 beta-hydroxy-16 alpha(-)[125I]iodowortmannin. These results suggested that the newly found isozyme was a complex composed of 46-kDa and 100-kDa peptides.

Androstadienes↗
PubMed1995

Permissive effect of ceramide on growth factor-induced cell proliferation.

Addition of bacterial sphingomyelinase to quiescent Swiss 3T3 cells effectively potentiated the platelet-derived growth factor (PDGF)-stimulated cell proliferation, though the enzyme by itself had little effect on the cell proliferation. Such potentiation of the cell growth could also be observed by the addition of ceramide, a product of the sphingomyelinase-catalysed reaction. In contrast, phosphocholine, another product of the enzyme reaction, had no synergistic effect on the action of PDGF. Treatment of the cells with sphingomyelinase or ceramide increased the cellular activity of mitogen-activated protein kinases (MAP kinases), which have been implicated in the regulation of cell proliferation. However, the synergistic effect of sphingomyelinase on the PDGF-induced cell growth could still be observed even when the cellular MAP kinase activity was fully activated by the growth factor alone. These results indicate that a ceramide-mediated cellular event(s) other than the MAP kinase activation is potentially involved in the regulation of cell growth.

3T3 Cells↗
PubMed1995

Neuronal localization of CD38 antigen in the human brain.

CD38 is a lymphocyte differentiation antigen which is involved in the cyclic ADP-ribose-mediated second messenger system. We provide immunochemical and immunohistochemical evidence for the expression of CD38 in the adult human brain. We used six polyclonal antibodies against synthetic CD38 polypeptides, in addition to four monoclonal antibodies already available. Brain CD38 was detectable by Western blotting after immunoaffinity purification of the brain extracts. Immunoperoxidase staining localized CD38 immunoreactivity to the perikarya and dendrites of many neurons, such as the cerebellar Purkinje cells, implying that CD38 is involved in the signal transduction within the central nervous system neurons.

ADP-ribosyl Cyclase↗
PubMed1995

Synergistic activation of rat brain phospholipase D by ADP-ribosylation factor and rhoA p21, and its inhibition by Clostridium botulinum C3 exoenzyme.

An activator of rat brain phospholipase D (PLD) that is distinct from the already identified PLD activator, ADP-ribosylation factor (ARF), was partially purified from bovine brain cytosol by a series of chromatographic steps. The partially purified preparation contained a 22-kDa substrate for Clostridium botulinum C3 exoenzyme ADP-ribosyltransferase, which strongly reacted with anti-rhoA p21 antibody, but not with anti-rac1 p21 or anti-cdc42Hs p21 antibody. Treatment of the partially purified PLD-activating factor with both C3 exoenzyme and NAD significantly inhibited the PLD-stimulating activity. These results suggest that rhoA p21 is, at least in part, responsible for the PLD-stimulating activity in the preparation. Recombinant isoprenylated rhoA p21 expressed in and purified from Sf9 cells activated rat brain PLD in a concentration- and GTP gamma S (guanosine 5'-O-(3-thiotriphosphate))-dependent manner. In contrast, recombinant non-isoprenylated rhoA p21 (fused to glutathione S-transferase) expressed in Escherichia coli failed to activate the PLD. This difference cannot be explained by a lower affinity of non-isoprenylated rhoA p21 for GTP gamma S, as the rates of [35S]GTP gamma S binding were very similar for both recombinant preparations and the GTP gamma S-bound form of non-isoprenylated rhoA p21 did not induce PLD activation. Interestingly, recombinant isoprenylated rhoA p21 and ARF synergistically activated rat brain PLD; a similar pattern was seen with the partially purified PLD-activating factor. The synergistic activation was inhibited by C3 exoenzyme-catalyzed ADP-ribosylation of recombinant isoprenylated rhoA p21 in a NAD-dependent manner. Inhibition correlated with the extent of ADP-ribosylation. These findings suggest that rhoA p21 regulates rat brain PLD in concert with ARF, and that isoprenylation of rhoA p21 is essential for PLD regulation in vitro.

ADP Ribose Transferases↗
PubMed1995

Cyclic AMP-increasing agents interfere with chemoattractant-induced respiratory burst in neutrophils as a result of the inhibition of phosphatidylinositol 3-kinase rather than receptor-operated Ca2+ influx.

Superoxide anion and arachidonic acid were produced in guinea pig neutrophils in response to a chemotactic peptide formyl-methionyl-leucyl-phenylalanine (fMLP). Both responses were markedly, but the former response to a phorbol ester was not at all, inhibited when the cellular cAMP level was raised by prostaglandin E1 combined with a cAMP phosphodiesterase inhibitor. Increasing cAMP was also inhibitory to fMLP-induced activation of phosphatidylinositol (PI) 3-kinase and Ca2+ influx without any effect on the cation mobilization from intracellular stores. The fMLP-induced respiratory burst was abolished when PI 3-kinase was inhibited by wortmannin or LY294002, but was not affected when Ca2+ influx was inhibited. On the contrary, fMLP released arachidonic acid from the cells treated with the PI 3-kinase inhibitors as well as from non-treated cells, but it did not so when cellular Ca2+ uptake was prevented. The chemotactic peptide activated PI 3-kinase even in cells in which the receptor-mediated intracellular Ca2+ mobilization and respiratory burst were both abolished by exposure of the cells to a permeable Ca(2+)-chelating agent. Thus, stimulation of fMLP receptors gave rise to dual effects, activation of PI 3-kinase and intracellular Ca2+ mobilization; both effects were necessary for the fMLP-induced respiratory burst. Increasing cellular cAMP inhibited the respiratory burst and arachidonic acid release as a result of the inhibitions of PI 3-kinase and Ca2+ influx, respectively, in fMLP-treated neutrophils.

1-Methyl-3-isobutylxanthine↗
PubMed1995

NAD(+)-dependent ADP-ribosylation of T lymphocyte alloantigen RT6.1 reversibly proceeding in intact rat lymphocytes.

Rat T lymphocyte alloantigen 6.1 (RT6.1), which was synthesized as the fusion protein with a maltose-binding protein in Escherichia coli, displayed NAD(+)-dependent auto-ADP-ribosylation in addition to an enzyme activity of NAD+ glycohydrolase. Such ADP-ribosylation of RT6.1 was also observed in lymphocytes isolated from rat tissues as follows. When intact rat lymphocytes expressing RT6.1 mRNA were incubated with [alpha-32P]NAD+, its radioactivity was incorporated into a cell surface protein with the M(r) of 31,000. The radiolabeled 31-kDa protein was released from the cell surface by treatment of the cells with phosphatidylinositol-specific phospholipase C and immunoprecipitated with anti-RT6.1 antiserum. The radioactivity incorporated into the 31-kDa protein was recovered as 5'-[32P]AMP upon incubation with snake venom phosphodiesterase and also removed by NH2OH treatment. These results suggested that the NAD(+)-dependent modification of the 31-kDa protein was due to ADP-ribosylation of glycosylphosphatidylinositol-anchored RT6.1 at an arginine residue. When intact lymphocytes, in which RT6.1 had been once modified by [32P]ADP-ribosylation, were further incubated in the absence of NAD+, there was reduction of the radioactivity in the [32P]ADP-ribosylated RT6.1. The reduced radioactivity was recovered from the incubation medium as [32P]ADP-ribose. This reduction was effectively inhibited by the addition of ADP-ribose to the reaction mixture. Moreover, readdition of NAD+ caused the ADP-ribosylation of RT6.1 again. Thus, the ADP-ribosylation of RT6.1 appeared to proceed reversibly in intact rat lymphocytes.

ADP Ribose Transferases↗