Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cyclic nucleotides (both cAMP and cGMP) stimulate the phosphorylation of several proteins of 65-70, 50-52, 21, 13, and 12 kD in rod outer segments (ROS) of the frog retina. Subcellular fractionation showed that phosphopeptides of 67, 21, 13, and 12 kD were soluble and phosphopeptides of 69, 67, 50-52, and 12 kD were membrane associated at physiological ionic strength. Components I and II, 13 and 12 kD, respectively, are the major cyclic nucleotide-dependent phosphoproteins of ROS and have been reported to be phosphorylated in the dark and dephosphorylated in the light. Under unstimulated conditions, phosphorylated Components I and II were found in the soluble fraction. Cyclic nucleotide stimulation of phosphorylation resulted in increased phospho-Components I and II in the soluble fraction, and phospho-Component II on the membrane. Light had no effect on the phosphorylation level of soluble Components I and II, but it caused a depletion within 1 s of the membrane-bound phospho-Component II. A half-maximal decrease in membrane-bound Component II was seen at 5 x 10(5) rhodopsins bleached per outer segment. The cyclic nucleotide-dependent protein kinase(s) were found primarily in the peripheral membrane fraction of ROS proteins. 8-bromo cyclic AMP was two orders of magnitude more effective than 8-bromo cyclic GMP at stimulating Component I and II phosphorylation. An active peptide of the Walsh inhibitor of cAMP-dependent protein kinase [PKI(5-22)amide] blocked the phosphorylation with an IC50 of 10 nM. Photoaffinity labeling studies with 8-N3-cAMP and 8-N3-cGMP revealed the presence of a 52-kD band specifically labeled with 8-N3-cAMP, but no specific 8-N3-cGMP labeling. These data suggest that cyclic nucleotide-dependent protein phosphorylation in ROS occurs via the activation of a cAMP-dependent protein kinase.
J Gen Physiol 1990 Mar
PMID:Regulation by light of cyclic nucleotide-dependent protein kinases and their substrates in frog rod outer segments. 215 94

We have cloned and determined the nucleotide sequence of a gene, pk, that lies immediately upstream from the gene encoding glycoprotein X in the short unique region of the alphaherpesvirus, pseudorabies virus (PRV). The gene has the potential to encode a protein of 334 amino acids, and is related to gene US3 of herpes simplex virus type 1 (HSV-1), which has been shown to encode a protein kinase. The predicted amino acid sequence encoded by the PRV pk gene is homologous to the corresponding sequence encoded by the HSV-1 US3 gene in the C-terminal catalytic domain, but diverges markedly in the N-terminal domain. As with HSV-1, the mRNA for the pk gene appears to be 3' coterminal with that for the glycoprotein downstream. An antiserum was raised against a protein generated from the fusion of part of the PRV pk catalytic domain with Escherichia coli beta-galactosidase. This specifically reacted with a previously described physically homogeneous protein kinase, PRV-PK, isolated from hamster fibroblasts lytically infected with PRV. Although the majority of the PRV-PK is found in the cytoplasm, some was also detected in purified PRV virions by using the same antibody; a similar distribution was found for the HSV-1 protein kinase, using an antiserum raised against the corresponding HSV-1 fusion protein. When presented with heatinactivated virions, purified PRV-PK (in common with certain cellular protein kinases also present in the virion) was able to phosphorylate in vitro the major virion phosphoprotein phosphorylated in vivo.
J Gen Virol 1990 Aug
PMID:The protein kinase encoded in the short unique region of pseudorabies virus: description of the gene and identification of its product in virions and in infected cells. 216 29

The complete nucleotide sequence is presented of the 2 x 67 kbp BamHI-EcoRV portion of the BamHI 10 fragment of the pseudorabies virus (PRV) genome (strain Ka) containing sequences upstream of the previously reported protein kinase gene, and completing the sequence of this 4008 bp fragment. It is predicted to contain a gene designated RSp40, homologous to gene US1 of herpes simplex virus type 1 (HSV-1), with the potential to encode a protein of 364 amino acids. Analysis of PRV mRNA synthesized in the presence and absence of cycloheximide indicated that, in contrast to its HSV-1 homologue, the PRV gene RSp40 does not specify an immediate-early mRNA. Between the RSp40 gene and the protein kinase gene are two reiterated sequences: one containing 11 tandem copies of a 35 nucleotide sequence and the other containing nine tandem copies of a 10 nucleotide sequence. The BamHI 10 and the BamHI 12 fragments of PRV contain the junctions between the short unique (US) and short repeat (RS) regions of the PRV genome. The nucleotide sequence of that portion of the BamHI 12 fragment containing US sequences was determined so that, by comparison with the nucleotide sequence of the BamHI 10 fragment, the junction between the US and RS regions could be defined. In BamHI 10 this was found to be at a point between the two reiterated sequences (which are in the RS region) and the protein kinase gene (which is in the US region). The organization of this region of the PRV genome is compared to that of other alphaherpesviruses.
J Gen Virol 1990 Oct
PMID:The structure of the pseudorabies virus genome at the end of the inverted repeat sequences proximal to the junction with the short unique region. 217 57

Highly purified growth hormone (GH) has been isolated from Atlantic salmon (Salmo salar) pituitaries by extraction with acid acetone, acidic precipitation, and reversed-phase high-performance liquid chromatography (HPLC). The yield was 2.5 mg/g wet tissue. The Atlantic salmon GH (sGH) emerged as a single symmetrical peak after HPLC on a reverse phase C18 column. SDS-gel electrophoresis revealed only one band with an estimated molecular weight of 23,000. Atlantic sGH showed a uniform molecular weight, but two-dimensional (2D) gel electrophoresis of the purified sGH revealed charge heterogeneity with pI's ranging from 6.5 to 8.2. Treatment of the purified sGH with alkaline phosphatase concentrated these different forms into a single more alkaline position (pI 8.2) indicating removal of acidic groups. These results were documented using both silver- and immunostaining of the 2D SDS gels. The purified sGH was phosphorylated in vitro by a calmodulin-dependent protein kinase. Phosphorylation of sGH may be a post-translational modification resulting in several molecular forms with variable acidity. Analysis of the amino acid composition of Atlantic sGH revealed homology with GHs isolated from other teleost species and the amino-terminal sequence showed only three different amino acids within the first 25 residues compared to GH isolated from chum salmon (Oncorhynchus keta) and coho salmon (Oncorhynchus kisutch) pituitaries. Atlantic sGH had a methionine as the amino-terminal residue. Antibodies against chum sGH cross-reacted with Atlantic sGH. Antibodies against either Atlantic or chinook (Oncorhynchus tschawytscha) salmon prolactin or human GH did not cross-react with Atlantic sGH. Atlantic sGH was shown to have a slight growth-promoting activity in the rat tibia assay.
Gen Comp Endocrinol 1990 Dec
PMID:Purification and characterization of Atlantic salmon growth hormone and evidence for charge heterogeneity. 228 75

A soluble protein kinase from the promastigote form of the parasitic protozoon Leishmania donovani was partially purified using DEAE-cellulose, Sephadex G-200 and phosphocellulose columns. The enzyme preferentially utilized protamine as exogenous phosphate acceptor. The native molecular mass of the enzyme was about 85 kDa. Mg2+ ions were essential for enzyme activity; other metal ions, e.g. Ca2+, Co2+, Zn2+ and Mn2+, could not substitute for Mg2+. cAMP, cGMP, Ca2+/calmodulin and Ca2+/phospholipid did not stimulate enzyme activity. The pH optimum of the enzyme was 7.0-7.5, and the temperature optimum 37 degrees C. The apparent Km for ATP was 60 microM. Phosphoamino acid analysis revealed that the protein kinase transferred the gamma-phosphate of ATP to serine residues in protamine. The thiol reagents p-hydroxymercuribenzoic acid, 5-5'-dithio-bis(2-nitrobenzoic acid) and N-ethylmaleimide inhibited enzyme activity; the inhibition by p-hydroxymercuribenzoic acid and 5-5'-dithio-bis(2-nitrobenzoic acid) was reversed by dithiothreitol.
J Gen Microbiol 1990 Jun
PMID:Partial purification and characterization of a soluble protein kinase from Leishmania donovani promastigotes. 238 43

Recombinant interferon-gamma (IFN-gamma) in contact with human embryonic fibroblasts or with a great variety of cells from different animal species was phosphorylated in the presence of [gamma-32P]ATP and magnesium ions by a protein kinase released in the culture medium. Using SDS-polyacrylamide gel electrophoresis, we found that both the monomeric (17 000 to 18 000) and dimeric (34 000 to 35 000) molecular weight forms of IFN-gamma became intensely radioactive. Serine, but not threonine or tyrosine, was phosphorylated. It is of interest that the kinase released from reputedly insensitive cells also phosphorylated IFN-gamma. The process did not noticeably degrade the antiviral functions of the molecule nor did it affect, at least in a detectable manner, its anti-proliferative effect on WISH or Daudi cells. Furthermore, the antigenic structure and its capacity to react with monoclonal antibodies were also unaltered. It is presently not known which biological function is regulated by the phosphorylating process.
J Gen Virol 1985 Jul
PMID:Phosphorylation of recombinant interferon-gamma by kinases released from various cells. 241 May 53

Antiviral effects of prostaglandins of the A series (PGAs) on Sendai, vaccinia and vesicular stomatitis viruses have previously been reported and a relationship between the antiviral actions of PGAs and interferons has been suggested. We have investigated the antiviral activity of PGAs on encephalomyocarditis (EMC) virus. Using single-cycle assays of virus replication our results indicate that PGAs only inhibit when present in the culture medium after the cells are infected, and that they are most effective during incubation periods including from 3 to 5 h post-infection. Furthermore, viral RNA synthesis is blocked in infected cells treated with PGA and, as a result, viral antigens are greatly reduced in the cytoplasm of the cells 5 h post-infection. Since the antiviral effect of PGAs is unperturbed by actinomycin D, when cellular RNA synthesis is greatly reduced, it appears unlikely that induction of new cellular proteins is the reason for the antiviral activity of PGAs. In separate experiments we were unable to demonstrate directly the induction of interferon, or of the two dsRNA-dependent enzymes, 2',5'-oligoadenylate synthetase and protein kinase, which are greatly increased in interferon-treated cells. Thus, we conclude that the antiviral activity of PGAs is unrelated to the antiviral action of interferons and involves a unique mechanism independent of cellular protein synthesis.
J Gen Virol 1985 Nov
PMID:Antiviral activity of prostaglandin A on encephalomyocarditis virus-infected cells: a unique effect unrelated to interferon. 241 95

beta-Adrenergic stimulation of ventricular heart cells results in the enhancement of two important ion currents that regulate the plateau phase of the action potential: the delayed rectifier potassium channel current (IK) and L-type calcium channel current (ICa). The temperature dependence of beta-adrenergic modulation of these two currents was examined in patch-clamped guinea pig ventricular myocytes at various steps in the beta-receptor/cyclic AMP-dependent protein kinase pathway. External applications of isoproterenol and forskolin were used to activate the beta-receptor and the enzyme adenylate cyclase, respectively. Internal dialysis of cyclic 3',5'-adenosine monophosphate (cAMP) or the catalytic subunit of cAMP-dependent protein kinase (CS), as well as the external addition of 8-chlorphenylthio cAMP (CPT-cAMP) was applied to increase intracellular levels of cAMP and CS. Isoproterenol-mediated increases in IK, but not ICa, were found to be very temperature dependent over the range of 20-37 degrees C. At room temperature (20-22 degrees C) isoproterenol produced a large (threefold) enhancement of ICa but had no effect on IK. In contrast, at warmer temperatures (30-37 degrees C) both currents increased in the presence of this agonist and the kinetics of IK were slowed at -30 mV. A similar temperature sensitivity also existed after exposure to forskolin, CPT-cAMP, cAMP, and CS, suggesting that this temperature sensitivity of IK may arise at the channel protein level. Modulation of IK during each of these interventions was accompanied by a slowing in IK kinetics. Thus, regulation of cardiac potassium channels but not calcium channels involves a temperature-dependent step that occurs after activation of the catalytic subunit of cAMP-dependent protein kinase.
J Gen Physiol 1989 May
PMID:Beta-adrenergic modulation of cardiac ion channels. Differential temperature sensitivity of potassium and calcium currents. 247 62

We used the whole-cell patch-clamp technique to study membrane currents in human airway epithelial cells. The conductive properties, as described by the instantaneous current-voltage relationship, rectified in the outward direction when bathed in symmetrical CsCl solutions. In the presence of Cl concentration gradients, currents reversed near ECl and were not altered significantly by cations. Agents that inhibit the apical membrane Cl conductance inhibited Cl currents. These conductive properties are similar to the conductive properties of the apical membrane Cl channel studied with the single-channel patch-clamp technique. The results suggest that the outwardly rectifying Cl channel is the predominant Cl-conductive pathway in the cell membrane. The steady-state and non-steady-state kinetics indicate that current flows through ion channels that are open at hyperpolarizing voltages and close with depolarization. These Cl currents were regulated by the cAMP-dependent protein kinase: when the catalytic subunit of cAMP-dependent protein kinase was included in the pipette solution, Cl channel current more than doubled. We also found that reducing extracellular osmolarity by 30% increased Cl current, suggesting that cell-swelling stimulated Cl current. Studies of transepithelial Cl transport in cell monolayers suggest that a reduction in solution osmolarity activates the apical Cl channel: reducing extracellular osmolarity stimulated a short-circuit current that was inhibited by Cl-free solution, by mucosal addition of a Cl channel antagonist, and by submucosal addition of a loop diuretic. These results suggest that apical membrane Cl channels may be regulated by cell volume and by the cAMP-dependent protein kinase.
J Gen Physiol 1989 Dec
PMID:Identification and regulation of whole-cell chloride currents in airway epithelium. 248 26

We have analysed the expression of vesicular stomatitis virus (VSV) proteins in virus-infected freshly explanted mouse peritoneal macrophages (resistant to virus replication), macrophages aged in vitro (permissive for virus replication) and freshly explanted macrophages from mice treated with antibody to interferon (IFN) alpha/beta (permissive for VSV replication). Our data showed that some VSV proteins (i.e. N/NS and G) were synthesized in virus-infected (1 p.f.u/cell) freshly harvested macrophages at early times after infection (3 to 6 h); the expression of such viral proteins was subsequently inhibited at 18 h post-infection. In contrast, a progressive increase in the expression of VSV proteins was observed in the macrophages aged in vitro and infected with VSV at 1 p.f.u./cell. Infection with a higher m.o.i. (16 p.f.u./cell) resulted in similar viral protein electrophoresis patterns for both aged macrophages and freshly explanted macrophages. Even at low m.o.i. a marked and progressive expression of all VSV proteins was observed in freshly harvested macrophages from mice treated with antibody to mouse IFN-alpha/beta. Higher levels of oligo-2',5'-adenylate synthetase (2-5AS) were found in freshly harvested macrophages than in either aged macrophages or those from mice treated with antibody to IFN. No dsRNA-dependent 67K protein kinase was detected in freshly harvested macrophages or peritoneal cells from untreated mice or mice treated with poly(rI).poly(rC) or Newcastle disease virus. The following conclusions can be drawn from these results. Low levels of spontaneous IFN-alpha/beta are responsible for the time-dependent inhibition of VSV protein synthesis in virus-infected freshly harvested macrophages; high levels of 2-5AS (in the absence of detectable levels of 67K protein kinase) appear to correlate with the progressive inhibition of VSV proteins; this natural antiviral state is highly effective only at low m.o.i.
J Gen Virol 1989 Jul
PMID:Studies on the mechanism of the interferon-mediated antiviral state to vesicular stomatitis virus in resting mouse peritoneal macrophages. 254 69


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>