Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.13 (protein kinase C)
 49,245 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The DNA hypomethylating agent 5-azacytidine greatly increased the reactivation of alphaherpesvirus saimiri-1 (alpha HVS) from latently infected rabbit dorsal root ganglia, although it inhibited the virus yield and plaque formation efficiency of alpha HVS in Vero cells. 12-O-Tetradecanoylphorbol 13-acetate (a protein kinase C activator) and sodium n-butyrate both had a stimulating action on replication in Vero cells but did not affect the release of alpha HVS from latently infected rabbit dorsal root ganglia.
J Gen Virol 1989 Sep
PMID:The effects of 5-azacytidine, 12-O-tetradecanoylphorbol 13-acetate and sodium n-butyrate on reactivation of alphaherpesvirus saimiri from explant cultures of latently infected rabbit dorsal root ganglia. 247 29

We investigated membrane currents activated by intracellular divalent cations in two types of molluscan pacemaker neurons. A fast and quantitative pressure injection technique was used to apply Ca2+ and other divalent cations. Ca2+ was most effective in activating a nonspecific cation current and two types of K+ currents found in these cells. One type of outward current was quickly activated following injections with increasing effectiveness for divalent cations of ionic radii that were closer to the radius of Ca2+ (Ca2+ greater than Cd2+ greater than Hg2+ greater than Mn2+ greater than Zn2+ greater than Co2+ greater than Ni2+ greater than Pb2+ greater than Sr2+ greater than Mg2+ greater than Ba2+). The other type of outward current was activated with a delay by Ca2+ greater than Sr2+ greater than Hg2+ greater than Pb2+. Mg2+, Ba2+, Zn2+, Cd2+, Mn2+, Co2+, and Ni2+ were ineffective in concentrations up to 5 mM. Comparison with properties of Ca2(+)-sensitive proteins related to the binding of divalent cations suggests that a Ca2(+)-binding protein of the calmodulin/troponin C type is involved in Ca2(+)-dependent activation of the fast-activated type of K+ current. Th sequence obtained for the slowly activated type is compatible with the effectiveness of different divalent cations in activating protein kinase C. The nonspecific cation current was activated by Ca2+ greater than Hg2+ greater than Ba2+ greater than Pb2+ greater than Sr2+, a sequence unlike sequences for known Ca2(+)-binding proteins.
J Gen Physiol 1989 Dec
PMID:Activation of three types of membrane currents by various divalent cations in identified molluscan pacemaker neurons. 255 42

1. 1-(5-isoquinoline sulfonyl)-2-methylpiperazine (H-7), a protein kinase C inhibitor, was found to inhibit con A stimulated [3H]thymidine incorporation and cytosolic protein kinase C (PKC) activation in T-lymphocytes of mouse spleen. 2. The inhibitory effect of H-7 was both concentration and time-dependent. 3. H-7 exerted no inhibition when T-lymphocytes have been preincubated with con A for 10 hours or longer. 4. These results support the notion that PKC is an important element of the con A mitogenic signal transduction mechanism and the PKC signal is completed within the first 10 hr of con A incubation.
Gen Pharmacol 1989
PMID:The protein kinase C inhibitor H-7 inhibits concanavalin A induced T-lymphocyte activation. 260 26

A 1.4 kb region downstream of the DNA polymerase gene of Autographa californica nuclear polyhedrosis virus was sequenced. Two open reading frames (ORFs) were identified of 927 and 474 bases in length. The 927 base ORF encodes a 34.8K protein as determined by in vitro translation of both hybrid-selected RNA and RNA synthesized in vitro from a 927 base ORF template. The predicted amino acid sequence of the 34.8K polypeptide (p34.8) reveals a hydrophobic N terminus, two potential N-glycosylation sites, and potential sites for phosphorylation by casein kinase I and protein kinase C. The p34.8 gene has a strong codon usage bias which is strikingly different from that of the polyhedrin gene. The two 5' ends of the 927 base ORF transcripts initiate from an ATAAG sequence and a GTAAG sequence 11 and 87 bases upstream of the ATG codon respectively. A short upstream reading frame is present in the leader sequence of the longer RNA. The transcripts have multiple 3' ends; the most proximal endpoint correlates with a polyadenylation signal overlapping the translational termination codon of the 927 base ORF. Transcripts of the latter were not observed early in the infection cycle but appeared 6 h after infection and were maximally expressed at 12 to 24 h post-infection. The late nature of these transcripts was confirmed by their sensitivity to aphidicolin and cycloheximide, inhibitors of DNA replication and protein synthesis respectively. Attempts to construct viral mutants carrying a deletion of the p34.8 gene and fusion with the beta-galactosidase gene suggest that the former gene is essential for viral replication.
J Gen Virol 1989 Sep
PMID:Sequence, transcription and translation of a late gene of the Autographa californica nuclear polyhedrosis virus encoding a 34.8K polypeptide. 267 27

Gonadotropin (taGTH) secretion from perifused fragments of tilapia pituitaries was stimulated in a dose-dependent manner by an analog of gonadotropin-releasing hormone ([D-Ala6] des Gly10 ethylamide LHRH; GnRHa) in a dose range of 1.28 to 128 pM. The baseline secretion rate and taGTH secretion in response to GnRHa were both reduced when the perifusion medium lacked Ca2+. Calcium ionophore (A23187; 0.1 mM) mimicked the effect of GnRHa but only in the presence of Ca2+. The addition of cobalt chloride to the medium at 0.6 mM initially caused an increase in taGTH secretion which was followed by its decrease. At a CoCl2 concentration of 1.3 mM, the baseline secretion rate remained low and the effect of GnRHa on taGTH secretion was attenuated. Withdrawal of CoCl2 from the medium was followed by an elevated basal secretion rate. Five-minute pulses of the protein kinase C activator, 1 oleyl-2-acetyl-rac-glycerol (OAG; 0.25 to 10.4 mM) stimulated taGTH secretion in the presence of Ca2+. With the reservation that the experiments were performed on fragments containing more than one pituitary cell type, the results indicate that the stimulation of GTH secretion in this fish is dependent, as in mammals, on extracellular Ca2+ and probably involves the activation of protein kinase C. However, the fact that taGTH may be stimulated to some extent in the absence of extracellular calcium or in the presence of 1.3 mM Co2+ may point to the possibility that Ca2+ is mobilized from intracellular stores as a result of GnRH stimulation or to the involvement of an additional mechanism of GnRH action in fish independent of calcium.
Gen Comp Endocrinol 1989 Aug
PMID:Gonadotropin secretion from perifused tilapia pituitary in relation to gonadotropin-releasing hormone, extracellular calcium, and activation of protein kinase C. 268 Jul 51

An analysis of the nucleoprotein (NP) of 29 different influenza A viruses by phosphopeptide fingerprinting revealed three prototype patterns. The first, which was a complex pattern consisting of six to seven phosphopeptides, another which was relatively simple consisted of two or three phosphopeptides, and a third one which was complex but was missing the main phosphopeptide shared by the two other patterns. Phosphoserine was the only labelled phosphamino acid detected. A tentative deduction of two of the phosphate attachment sites (serine residues at positions 3 and 473) could be made by comparison of the known amino acid sequences of the NPs of 25 strains. No correlation was found between species specificity or subtype or year of isolation of the strains. During the infectious cycle the fingerprint underwent significant changes, indicating subtle phosphorylation and dephosphorylation of the NP at various stages during viral multiplication. Most of the phosphopeptides were metabolically stable; however one major phosphopeptide, which was not found in the NP of mature virions, exhibited a high turnover (presumably serine at position 3). The phosphopeptide fingerprint could be significantly influenced in vivo by the specific stimulation of cellular protein kinase C by the phorbol ester 12-O-tetradecanoylphorbol 13-acetate or by its inhibition with the isoquinoline sulphonamide H7.H7 specifically inhibited the replication of influenza A viruses by deregulation of viral protein synthesis without interfering with the multiplication of a parainfluenza virus (Newcastle disease virus), an alphavirus (Semliki Forest virus) or a flavivirus (West Nile). Therefore the correct phosphorylation of the NP of influenza viruses appears to be essential for influenza virus replication.
J Gen Virol 1989 Sep
PMID:Differential phosphorylation of the nucleoprotein of influenza A viruses. 277 38

The present study investigated the effects of 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17,20 B-P) on (1) ovulation of isolated perch follicles in which the extrafollicular (EF) ovarian tissue had been removed; (2) prostaglandin F (PGF) and prostaglandin E (PGE) synthesis in EF tissue and intact (= follicles attached to EF tissue) and isolated follicles by radioimmunoassay and [14C]arachidonic acid incorporation; and (3) proteolysis in EF tissue and intact and isolated follicles by substrate sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In addition, the ovulatory and proteolytic effects of the phorbol ester, phorbol-12-myristate-13-acetate (PMA), and the calcium ionophore A23187 on 17,20B-P-stimulated follicles were also studied in the presence/absence of indomethacin (IM) and nordihydroguaiaretic acid (NDGA). Ultrastructural analyses revealed that the preparation of isolated follicles also removed the surface epithelium of the follicle. While 17,20B-P stimulated ovulation and an increase in PGF and PGE in incubates of intact perch follicles, it did not in incubates of isolated follicles. In contrast, PMA, A23187, and a combination of PMA and A23187 stimulated ovulation of these isolated follicles. PMA/A23187-induced ovulation could be blocked by NDGA but not IM, and two hydroxyeicosatetraenoic acids (11- and 15-HETEs) were capable of partially reversing the NDGA block. Incorporations with [14C]arachidonic acid revealed that the EF tissue had a significant potential to produce PGF; however, 17,20B-P did not stimulate an increase in PGF or PGE (measured by RIA) in incubates of EF tissue alone. In addition, neither ovulation nor an increase in prostaglandins was observed in cocultures of isolated follicles and EF tissue. One major protease (66 kDa) was observed in the medium during incubation of intact and isolated perch follicles. No protease activity was present in incubates of EF tissue alone. Protease activity in 17,20B-P-stimulated incubates of intact tissue was significantly higher than in steroid-stimulated incubates of isolated follicles. Protease activity increased in the medium during incubation with PMA or a combination of PMA and A23187. This activity was blocked by NDGA but not IM. The NDGA block was partially reversed by 11-HETE. The combined results suggest that there is an interaction of EF tissue and follicle that is necessary, particularly for the stimulation of ovulation and prostaglandin production. Further, the results with phorbol esters and NDGA suggest that the follicular control of ovulation in perch may involve protein kinase C acting through the production of a lipoxygenase product.
Gen Comp Endocrinol 1989 Sep
PMID:In vitro ovulation, prostaglandin synthesis, and proteolysis in isolated ovarian components of yellow perch (Perca flavescens): effects of 17 alpha,20 beta-dihydroxy-4-pregnen-3-one and phorbol ester. 279 31

Interactions between the different signaling roles of myo-inositol 1,4,5-trisphosphate and 1,2-diacylglycerol, the products of agonist-stimulated phosphatidylinositol 4,5-bisphosphate breakdown, are assessed in isolated rat hepatocytes. Measurements of the kinetics of accumulation of individual [3H]inositol phosphates after the addition of different Ca2+-mobilizing agonists in general support the role of inositol 1,4,5-trisphosphate as the second messenger responsible for release of sequestered intracellular Ca2+. Various agonists, when added at maximal concentrations, however, produce qualitatively and quantitatively different responses, which reflect varying abilities of the agonists to activate phospholipase C. Qualitative differences are revealed by a pronounced biphasic pattern to the Ins(1,4,5)P3 accumulation after vasopressin and phenylephrine stimulation, which is indicative of negative feedback. It is suggested that this effect is mediated by a partial diacylglycerol activation of protein kinase C, which in vitro causes an activation of inositol phosphate 5-phosphatase and hence promotes removal of Ins(1,4,5)P3 to Ins(1,4)P2. An alternative mechanism proposed by Biden and Wollheim (1986) of a secondary Ca2+ activation of Ins(1,4,5)P3 3-kinase is considered less likely as a general mechanism, since highly purified kinase prepared from rat brain shows only an inhibition by Ca2+. Glucagon, 8-Br-cAMP, and EGF induce small increases of Ins(1,4,5)P3 in hepatocytes, together with slower and smaller increases of cytosolic free Ca2+ than those produced by vasopressin or phenylephrine, with Ca2+ being mobilized from the same intracellular pools with each of the agonists. The Ca2+-mobilizing effect of glucagon, therefore, may be entirely due to a cAMP-dependent process, although a direct receptor-mediated activation of phospholipase C, as suggested by Wakelam et al. (1986), remains a possibility. The EGF receptor appears to be coupled to phospholipase C, presumably via a G-protein. It is speculated that the mechanism by which cAMP increases Ins(1,4,5)P3 levels in hepatocytes could either be by phosphorylation and inhibition of inositol phosphate 5-phosphatase or by phosphorylation and facilitation of the coupling between the G-protein and phospholipase C. When protein kinase C is maximally activated by pretreatment of hepatocytes with PMA, the stimulatory effects of phenylephrine, glucagon, 8-Br-cAMP, and EGF on the accumulation of inositol phosphates and increase of cytosolic free Ca2+ are largely inhibited.(ABSTRACT TRUNCATED AT 400 WORDS)
Soc Gen Physiol Ser 1987
PMID:Mechanisms involved in receptor-mediated changes of intracellular Ca2+ in liver. 285 Jun 13

K influx into resealed human red cell ghosts increases when the ghosts are swollen. The influx demonstrates properties similar to volume-sensitive K fluxes present in other cells. The influx is, for the most part, insensitive to the nature of the major intracellular cation and therefore is not a K-K exchange. The influx is much greater when the major anion is Cl than when the major anion is NO3; Cl stimulates the flux and, at constant Cl, NO3 inhibits it. Increase in the influx rate is rapid when shrunken ghosts are swollen or when NO3 is replaced by Cl. The volume-sensitive K influx requires intracellular MgATP at low concentrations, and ATP cannot be replaced by nonhydrolyzable ATP analogues. The volume-sensitive influx is inhibited by Mg2+ and by high concentrations of vanadate, but is stimulated by low concentrations of vanadate. It is not modified by cAMP, the removal of Ca2+ by EGTA, substances that activate protein kinase C, or by inhibition of phosphatidylinositol kinase. The influx is inhibited by neomycin and by trifluoperazine.
J Gen Physiol 1988 Nov
PMID:Volume-sensitive K influx in human red cell ghosts. 285 1

The polypeptide hormones that govern the proliferation and differentiation of the mature immune system and hematopoiesis are collectively referred to as lymphokines. We have examined a number of biochemical and molecular events stimulated by several unique lymphokines that exhibit proliferative activity on lymphoid and myeloid cell lines. IL-2 and several members of the colony-stimulating factors (multi-CSF, G-CSF, and GM-CSF) stimulate a similar pattern of cellular phosphorylation, including the prominent phosphorylation of a 68-kD substrate present in numerous distinct lineage cell lines. The 68-kD substrate is phosphorylated by protein kinase C on threonine residues and is primarily cytosolic. Another kinase system activated by either physiological ligand or synthetic diacylglycerol phosphorylated the 40S ribosomal S6 protein in a dose-dependent manner. The increased phosphorylation of S6 protein was associated with enhanced chain elongation in vitro. The kinase responsible for the in situ phosphorylation, however, was not protein kinase C but another physicochemically distinct Mg++-dependent enzyme (termed S6 kinase). These studies suggested that although protein kinase C was activated by diacylglycerol, another kinase, S6 kinase, was the effector enzyme involved in the phosphorylation of the 40S protein. IL-2 and all other lymphokines tested stimulated the transcription of the nuclear protooncogenes c-fos, c-myc, and c-myb, as well as a member of the heat shock family of proteins, HSP 70. Phorbol esters also stimulated similar gene expression; however, cAMP analogue inhibited phorbol ester- or ligand-induced c-myc expression. cAMP agonists are antiproliferative to all the growth factors tested.
Soc Gen Physiol Ser 1988
PMID:Biochemical and molecular events controlled by lymphokine growth factors. 307 55


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