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Query: EC:2.7.11.1 (
protein kinase
)
81,284
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The appearance of a recently described
protein kinase
activity (virus-induced
protein kinase
, ViPK) has been studied during infection of hamster fibroblasts with pseudorabies virus or with herpes simplex virus type 1 (HSV-1). An enzyme activity with comparable catalytic properties was induced in both cases, and had broadly similar kinetics of appearance to that of the viral
DNA polymerase
. The amount of active ViPK detected depended on the multiplicity of infection, and no ViPK was induced after the viruses had been subjected to irradiation with u.v. light. When cells were infected with the tsK mutant of HSV-1, ViPK was induced at the permissive but not at the restrictive temperature. The ViPK preparations obtained from cells infected with each virus differed in chromatographic properties on anion-exchange and gel-permeation resins. These results indicate that expression of the viral genome is required for induction of ViPK. They suggest that the enzyme may be encoded by the viral genome, but do not provide proof of this.
...
PMID:Characteristics of the induction of a new protein kinase in cells infected with herpesviruses. 301 70
After a single injection of oestradiol benzoate (1.5 mg/kg) to oestrogen-withdrawn chickens, there was an increase in magnum wet weight, DNA polymerase alpha activity, adenosine-3',5'-monophosphate-dependent protein-kinase activity and estrogen-receptor concentration, as measured over 36 h. Besides these intracellular proteins, the secretory proteins ovalbumin and conalbumin were also augmented, and detailed time-course studies were performed. Early induction kinetics for ovalbumin and conalbumin synthesis, which differed for each protein, were independent of the dose of oestradiol benzoate injected if it exceeded 0.1 mg/kg. After 6 h for ovalbumin and 2 h for conalbumin, the induction curves diverged according to the dose of hormone administered and in correlation with the persistence of elevated nuclear oestrogen-receptor concentrations, a result confirmed with 11 beta-methoxy-17 alpha-ethynyloestradiol (R 2858), a powerful synthetic oestrogen. When oestradiol benzoate (1 mg/kg) and progesterone (3 mg/kg) were injected simultaneously, the rate of conalbumin sythesis, during the first 6-8 h, was lower than that observed in animals injected with oestradiol benzoate alone. However at later times conalbumin synthesis was greater in animals receiving both hormones than with oestradiol alone. In contrast, the rate of ovalbumin synthesis after the combined injection was higher than that induced by either hormone alone throughout the entire experimental period. In order to study further the synergistic and antagonistic activities of these two hormones, a single injection of progesterone (3 mg/kg) was administered 6, 12 or 18 h after 1.5 mg/kg oestradiol benzoate. Progesterone administration resulted in a reduction in cytoplasmic, nuclear and total oestrogen receptor concentration for at least 6 h when compared with the values in birds treated with oestrogen alone.
DNA polymerase
and
protein kinase
activities were also reduced during this period. Subsequently, all parameters increased, and by 18-24 h after progesterone treatment, reached values higher than those observed in animals receiving oestrogen alone.
...
PMID:Steroid receptors and effects of oestradiol and progesterone on chick oviduct proteins. 624 83
Human cytomegalovirus (HCMV), purified exclusively from the extracellular media, contained a
DNA polymerase
activity in addition to a
protein kinase
activity. The
DNA polymerase
expressed its maximum activity in the presence of 5 to 10 mM-MgCl2. The enzyme was able to use effectively activated calf thymus DNA, poly(dA).oligo(dT)12--18 and poly(dC).oligo(dG)12--18 as the template primers. The DNA polymerizing activity was eluted with 0.18 to 0.2 M-KCl from a phosphocellulose column. It was relatively resistant to phosphonoacetic acid inhibition even at a high concentration of 100 micrograms/ml with activated calf thymus DNA as the template primer, but the
DNA polymerase
activity was totally suppressed at this concentration when poly(dA).oligo(dT)12--18 was used as the template primer. The enzyme activity was inhibited by ammonium sulphate at 0.01 to 0.3 M with either activated calf thymus DNA or poly(dA).oligo(dT)12--18 as the template primer. The
protein kinase
has maximum activity in the presence of 10 to 20 mM-MgCl2, and preferred virion proteins as phospho-acceptor to protamine sulphate. Histone, caesin and bovine serum albumin (BSA) were found to be poor substrates. The phosphorylated protein pattern of the in vivo [32P]orthophosphate-labelled virions was not identical to that of the in vitro phosphorylated Nonidet P40-dissociated virions, although seven phosphorylated polypeptides did co-migrate in SDS--polyacrylamide gel electrophoresis (SDS--PAGE). Procedures known to solubilize virions showed that the
DNA polymerase
and
protein kinase
were internal components of the virion.
...
PMID:Human cytomegalovirus-associated DNA polymerase and protein kinase activities. 627 14
The recently described
protein kinase
activity in hepatitis B virus core antigen particles (Albin and Robinson, J. Virol. 34:297-302, 1980) has been demonstrated here in the liver-derived core particles of ground squirrel hepatitis virus. Both
protein kinase
activities were initially associated with
DNA polymerase
-positive heavy core particles in CsCl density equilibrium gradients and shifted to polymerase-negative cores during the course of purification. The major core-associated polypeptide of each virus was the dominant species labeled. A variable number of other polypeptide species were also labeled by this reaction. Tryptic peptide mapping of both major and minor phosphorylated polypeptides of each virus resulted in similar patterns, suggesting that many of the sites of phosphorylation were the same in the components of each core particle. Hydrolysis of these phosphorylated core particles revealed a major phosphoamino acid as serine and a minor phosphoamino acid as threonine. The products of the
protein kinase
reaction in both human hepatitis B and ground squirrel hepatitis virus core particles, then, share many characteristics. The possible function(s) of this
protein kinase
activity is discussed in the light of similarly characterized activities in other animal viruses.
...
PMID:Core particles of hepatitis B virus and ground squirrel hepatitis virus. II. Characterization of the protein kinase reaction associated with ground squirrel hepatitis virus and hepatitis B virus. 710 41
We observed that lipopolysaccharide (LPS, 1 micrograms/ml) can suppress [3H]thymidine incorporation into acid-insoluble fraction in a mouse macrophage cell line J774 (over 70% at 6 h) without affecting the uptake of [3H]thymidine or
DNA polymerase
activity. Paralleling this suppression, a decrease in the thymidine kinase (TK) activity, but not of thymidine monophosphate (TMP) kinase and thymidine diphosphate (TDP) kinase, was observed. LPS dose-dependently increased intracellular cAMP levels to about 3.5-times basal at 6 h, proportionally to the decrease of the TK activity. Elevation of intracellular cAMP by several reagents also decreased TK activity. Apparently LPS treatment elevates cAMP concentration by decreasing the low Km cAMP phosphodiesterase activity (58% at 6 h). The time course of
cAMP-dependent protein kinase
(PK-A) activity during the first 6 h after LPS treatment correlated with that of cAMP concentration. Treatment with a PK-A inhibitor restored about 63% of LPS-induced reduction of TK activity at 6 h. At longer times, however, there was a discrepancy between the change of cAMP concentration or PK-A activity and the reduction of TK activity. Therefore,
protein kinase
activation caused by the accumulation of intracellular cAMP probably triggers some mechanism responsible for the reduction of the TK activity.
...
PMID:The role of cyclic AMP in the lipopolysaccharide-induced suppression of thymidine kinase activity in macrophage. 769 50
The p53 tumour-suppressor protein controls the expression of a gene encoding the p21 cyclin-dependent
protein kinase
(CDK) regulator. Levels of p21 protein are increased in senescent cells and p21 overexpression blocks the growth of tumour cells. In normal human cells, but not in many tumour cells, p21 exists in a quaternary complex with a cyclin, a CDK, and the proliferating-cell nuclear antigen (PCNA). p21 controls CDK activity, thereby affecting cell-cycle control, whereas PCNA functions in both DNA replication and repair. Here we use simian virus 40 DNA replication in vitro to show than p21 directly inhibits PCNA-dependent DNA replication in the absence of a cyclin/CDK. Furthermore, p21 blocks the ability of PCNA to activate DNA polymerase delta, the principal replicative
DNA polymerase
. This regulation results from a direct interaction between p21 and PCNA. Thus, during p53-mediated suppression of cell proliferation, p21 and PCNA may be important for coordinating cell-cycle progression, DNA replication and repair of damaged DNA.
...
PMID:The p21 inhibitor of cyclin-dependent kinases controls DNA replication by interaction with PCNA. 791 Dec 27
Cdk-interacting protein 1 (Cip1) is a p53-regulated 21-kDa protein that inhibits several members of the
cyclin-dependent kinase
(
CDK
) family. It was initially observed in complexes containing CDK4, cyclin D, and proliferating cell nuclear antigen (PCNA). PCNA, in conjunction with activator 1, acts as a processivity factor for eukaryotic
DNA polymerase
(pol) delta, and these three proteins constitute the pol delta holoenzyme. In this report, we demonstrate that Cip1 can also directly inhibit DNA synthesis in vitro by binding to PCNA. Cip1 efficiently inhibits simian virus 40 replication dependent upon pol alpha, activator 1, PCNA, and pol delta, and this inhibition can be overcome by additional PCNA. Simian virus 40 DNA replication, catalyzed solely by high levels of pol alpha-primase complex, is unaffected by Cip1. Using the surface plasmon resonance technique, a direct physical interaction of PCNA and Cip1 was detected. We have observed that Cip1 efficiently inhibits synthesis of long (7.2 kb) but not short (10 nt) templates, suggesting that its association with PCNA is likely to impair the processive movement of pol delta during DNA chain elongation, as opposed to blocking assembly of the pol delta holoenzyme. The implications of the Cip1-PCNA interaction with respect to regulation of DNA synthesis, cell cycle checkpoint control, and DNA repair are discussed.
...
PMID:Cdk-interacting protein 1 directly binds with proliferating cell nuclear antigen and inhibits DNA replication catalyzed by the DNA polymerase delta holoenzyme. 791 43
The same point mutation in the human cytomegalovirus UL97 open reading frame was found in three independently isolated ganciclovir-resistant mutants of strain AD169. Point mutations in the
DNA polymerase
genes of these strains have been previously identified (N.S. Lurain, K.D. Thompson, E.W. Holmes, and G.S. Read, J. Virol. 66:7146-7152, 1992). All three strains are, therefore, double mutants. To determine the contribution of the UL97 mutation to the high ganciclovir resistance of these mutants, the mutation from the ganciclovir-resistant strain D6/3/1 was transferred to the wild-type strain AD169 to produce the recombinant R6HS. The ganciclovir resistance of R6HS is 4-fold lower than that of D6/3/1 but 10-fold higher than that of AD169. R6HS, like AD169, is sensitive to the nucleotide analogs (S)-1-[(3-hydroxy-2-phosphonylmethoxy) propyl]adenine and (S)-1-[(3-hydroxy-2-phosphonylmethoxy)propyl]cytosine. Ganciclovir phosphorylation in R6HS-infected cells was at the same reduced level as that found in cells infected with the parental mutant D6/3/1. The same G-to-T transversion at nucleotide 1380 in the UL97 coding sequence is present in both R6HS and D6/3/1. This mutation results in the substitution of isoleucine for methionine at amino acid residue 460. In an alignment of the R6HS UL97 amino acid sequence with the amino acid sequences of a wide range of
protein kinase
family members, methionine 460 lies within a highly conserved region which may function in nucleotide binding and phosphate transfer.
...
PMID:Mutation in the UL97 open reading frame of human cytomegalovirus strains resistant to ganciclovir. 820 15
We have investigated the pathogenicity of a US3
protein kinase
-deficient mutant (L1 BR1) of herpes simplex virus type 2 (HSV-2) for 4-week-old ICR mice to define the role of the viral
protein kinase
in virus-host interaction. When mice were intraperitoneally infected with 10(5)PFU of L1 BR1, the virus disappeared from the peritoneal cavity by 2 days postinfection and failed to induce any significant histopathological changes in the liver and spleen although viral antigens were occasionally detected in the epithelial cells of small bile ducts and small vascular wall. The parental virus (HSV-2 186) and a revertant of the mutant (L1 B-11) both caused severe hepatitis, and viral antigens were clearly detected in the hepatocytes and Kupffer cells in the focal necrotic areas. Both of the virulent viruses, unlike L1 BR1, could produce infectious progeny and cytopathic effects in freshly harvested peritoneal macrophages. The growth of L1 BR1 in peritoneal macrophages was restricted at a stage of or prior to viral DNA synthesis but after the induction of viral
DNA polymerase
. In addition, the production and/or the spread of mutant in mouse embryo fibroblasts (MEF) was found to be much more effectively suppressed by cocultivation of peritoneal macrophages than that of 186. An almost complete inhibition of L1 BR1-plaque formation was observed at a macrophage-to-MEF ratio of 4:1. These results suggest that the attenuation of L1 BR1 following intraperitoneal infection is primarily due to its high sensitivity to intrinsic and extrinsic inhibition of peritoneal macrophages and that the US3
protein kinase
may play a role in viral DNA replication in peritoneal macrophages.
...
PMID:The pathogenicity of a US3 protein kinase-deficient mutant of herpes simplex virus type 2 in mice. 825 88
Adenovirus
DNA polymerase
(AdPol) exists as a complex with the preterminal protein (pTP) and is essential for both initiation and elongation stages of viral DNA replication. Recent evidence from our laboratory indicates that AdPol is a phosphoprotein and that the major in vivo phosphorylation site, serine 67, occurs within the consensus substrate recognition sequence for cdc2 kinases. In this study, we found that a
protein kinase
which also exhibits histone H1 phosphorylation activity is stably associated with AdPol. AdPol forms a multimeric complex with this histone H1 kinase and pTP in HeLa cells infected with adenovirus or coinfected with recombinant vaccinia viruses encoding AdPol and pTP. The associated
protein kinase
and the p34cdc2 kinase phosphorylate AdPol at the same sites which are utilized in vivo, suggesting that the p34cdc2 kinase or a related kinase may be involved in the in vivo phosphorylation of AdPol. Serine 67 is also one of the major in vitro phosphorylation sites, and the substitution of alanine for serine at this position abolishes DNA replication initiation activity of AdPol.
...
PMID:Adenovirus DNA polymerase is phosphorylated by a stably associated histone H1 kinase. 834 26
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