Gene/Protein Disease Symptom Drug Enzyme Compound
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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)

Cardiac sarcoplasmic reticulum (SR) ATP-dependent Ca2+-uptake was found to be depressed in 4 month streptozotocin-induced diabetic rats. Calmodulin, cAMP-dependent protein kinase and K+ stimulated Ca2+-uptake to similar degrees in SR from both control diabetic rats. Long chain acylcarnitine (7 microM) decreased Ca2+-transport in control rats by 46% but only 26% in diabetic animals. The data suggests that the depression in cardiac SR Ca2+-uptake activity in diabetic rats is non-specific in origin and not a result of alterations in regulation of SR function.
Gen Pharmacol 1984
PMID:Depression of calcium transport in sarcoplasmic reticulum from diabetic rats: lack of involvement by specific regulatory mediators. 623 Feb 83

Subcellular fractionation of rat and human cells transformed by the adenovirus type 12 (Ad-12) EcoRI-C DNA fragment showed that the 41000 mol. wt. (41K) E1a and 52K E1b proteins were present in the nucleus and cytoplasm at approximately equal concentrations. The 18K E1b protein was associated with the nuclear, mitochondrial, lysosomal and membrane fractions. The 41K E1a protein was also associated with various cytoskeletal structures (probably microtubules and 10 nm filaments) in Ad-12-transformed cells. The Ad-12 E1 41K and 52K proteins have been partially purified from transformed and infected cells. Using these preparations the 52K protein has been shown to exist under non-reducing conditions and probably in vivo as a 100K dimer stabilized by intermolecular disulphide bonds. The 41K protein bound strongly to histones H1 and H4 but much more weakly to H2A, H2B and H3. It did not interact with other comparable basic proteins or with the cytoskeletal components actin, tropomyosin and calmodulin. Although the 41K E1 a protein bound to histones in vitro it is probable that such an interaction may not occur in vivo as very little of the adenovirus protein co-purified with chromatin from transformed cells. None of the Ad-12 E1 proteins showed any ATPase or protein kinase activity.
J Gen Virol 1984 Dec
PMID:Adenovirus type 12 early region 1 proteins: a study of their subcellular localization and protein-protein interactions. 623 9

The antigenicity of the avian sarcoma virus (ASV)-coded src-gene product pp60src, which is responsible for fibroblast transformation after ASV infection, has been investigated in STU mouse fibrosarcoma cell lines and the corresponding immune response in syngeneic mice has been determined. The development of effective anti-pp60src antibody titres depends on the mode and stie of injection of tumour cells and parallels tumour growth. It was found that mouse immunoglobulin heavy chains are unable to serve as substrate for the protein kinase activity of pp60src. Therefore, an indirect protein kinase absorption (PKA) test was initiated to demonstrate recognition of the protein kinase activity associated with the src-gene product. The availability of syngeneic mice and the corresponding ASV-transformed tumour cells should facilitate studies designed to elucidate the possible relationship between the cytoplasmic pp60src and ASV-induced tumour-specific surface antigens (TSSA), for example, by allowing the production of stable mouse hybridomas synthesizing antibodies specific for pp60src and TSSA.
J Gen Virol 1980 Jun
PMID:The immune response against the ASV-coded src-gene product in syngeneic mice. 624 87

The primary purpose of this study was to determine whether various agents (adenosine 3-thiotriphosphate [ATP gamma S], trifluoperazine [TFP], troponin I, the catalytic subunit of the cyclic adenosine 3',5'-monophosphate dependent protein kinase [C-subunit], and calmodulin [CaM]) could be used to classify skinned fiber types, and then to determine whether the proposed mechanisms for Ca2+ regulation were consistent with the results. Agents (ATP gamma S, TFP, C-subunit, CaM) expected to alter a light chain kinase-phosphatase system strongly affect the Ca2+-activated tension in skinned gizzard smooth muscle fibers, whereas these agents have no effect on skinned mammalian striated and scallop adductor fibers. Troponin I, which is known to bind strongly to troponin C and CaM, inhibits Ca2+ activation of skinned mammalian striated and gizzard fibers but not scallop adductor muscle. The results in different types of skinned fibers are consistent with proposed mechanisms for Ca2+ regulation.
J Gen Physiol 1981 Feb
PMID:Calcium-regulatory mechanisms. Functional classification using skinned fibers. 626 61

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.
J Gen Virol 1981 Nov
PMID:Human cytomegalovirus-associated DNA polymerase and protein kinase activities. 627 14

In previous efforts to characterize sarcoplasmic reticulum function in human muscles, it has not been possible to distinguish the relative contributions of fast-twitch and slow-twitch fibers. In this study, we have used light scattering and 45Ca to monitor Ca accumulation by the sarcoplasmic reticulum of isolated, chemically skinned human muscle fibers in the presence and absence of oxalate. Oxalate (5 mM) increased the capacity for Ca accumulation by a factor of 35 and made it possible to assess both rate of Ca uptake and relative sarcoplasmic reticulum volume in individual fibers. At a fixed ionized Ca concentration, the rate and maximal capacity (an index of sarcoplasmic reticulum volume) both varied over a wide range, but fibers fell into two distinct groups (fast and slow). Between the two groups, there was a 2- to 2.5-fold difference in oxalate-supported Ca uptake rates, but no difference in average sarcoplasmic reticulum volumes. Intrinsic differences in sarcoplasmic reticulum function (Vmax, K0.5, and n) were sought to account for the distinction between fast and slow groups. In both groups, rate of Ca accumulation increased sigmoidally as [Ca++] was increased from 0.1 to 1 microM. Apparent affinities for Ca++ (K0.5) were similar in the two groups, but slow fibers had a lower Vmax and larger n values. Slow fibers also differed from fast fibers in responding with enhanced Ca uptake upon addition of cyclic AMP (10(-6) M, alone or with protein kinase). Acceleration by cyclic AMP was adequate to account for adrenaline-induced increases in relaxation rates previously observed in human muscles containing mixtures in fast-twitch and slow-twitch fibers.
J Gen Physiol 1982 Apr
PMID:Calcium accumulation by the sarcoplasmic reticulum in two populations of chemically skinned human muscle fibers. Effects of calcium and cyclic AMP. 627 58

In vitro experiments support the ideal that the actin-activated MgATPase activity of smooth muscle myosin and myosin from nonmuscle cells is regulated by the phosphorylation of the 20,000 dalton light chain of myosin. Experiments with intact smooth muscles support this mechanism but also raise the possibility that tension may be maintained in the presence of partial dephosphorylation (12). The possibility that smooth muscle contraction may also be modulated by additional regulatory systems (13,29) is to be expected based on experience with other types of muscle. The enzyme myosin light chain kinase catalyzes the phosphorylation of the 20,000 dalton light chain of myosin. This enzyme requires Ca2+-calmodulin for activity. The activity of myosin kinases that have been isolated from avian smooth muscle cells (8) or human platelets (16) can be decreased by phosphorylation. This phosphorylation is catalyzed by cAMP-dependent protein kinase and decreases myosin kinase activity by interfering with the binding of Ca2+-calmodulin. A number of different phosphatases have been purified from smooth muscle (22). These phosphatases play an important role in determining the state of phosphorylation of myosin and myosin kinase. Two areas of particular interest at present are the regulation of phosphatase activity and the physiological significance of myosin kinase phosphorylation.
Soc Gen Physiol Ser 1982
PMID:Regulation of contractile proteins by reversible phosphorylation of myosin and myosin kinase. 629 99

We have recently found that, in vitro, the murine leukaemia virus (MuLV)-associated protein kinase activity predominantly phosphorylates Pr65gag, a virus protein present in relatively small amounts in partially purified virus preparations. Other virus proteins, such as p10, Pr27gag and Pr40gag, are also phosphorylated in vitro, but to a lesser degree. Furthermore, when immature core subparticles which are enriched in Pr65gag are prepared from virions by Sepharose 6B exclusion column chromatography, about 50% of the kinase activity (as assayed with the exogenous substrate phosvitin) remains associated with the cores. We report here that this core-associated activity is distinct from Pr65gag since it can be separated from Pr65gag by chromatography on denatured DNA--cellulose columns followed by centrifugation of the 0.2 M-NaCl-eluted fraction. Under these conditions, Pr65gag is pelleted while the kinase activity, which can phosphorylate both endogenous (MuLV Pr65gag and p10) as well as exogenous (phosvitin) substrates, remains in the supernatant. Interestingly, when the amount of Pr65gag is reduced, as in such preparations, p10 then becomes more heavily phosphorylated.
J Gen Virol 1983 Jan
PMID:Separation of a murine leukaemia virus protein kinase activity from its Pr65gag polyprotein substrate after DNA--cellulose chromatography. 629 9

Pituitary cyclic AMP-dependent protein kinase (cAMP-PK) activity ratios are not increased in response to thyrotropin-releasing hormone (TRH) in old chickens (retired White Leghorn breeders). This reduced responsiveness may be due to reduced hypothalamic function, reduced thyrotrope function, or to a reduction in TRH membrane receptors. The thyroid cAMP-PK activity ratio of old males does not respond to TRH treatment but the thyroid of old females does have an increased activity ratio ater TRH injection. Both males and females have a much higher basal cAMP-PK activity ratio than young birds. This higher basal level is thought to be due to an increased thyroid-stimulating hormone (TSH) stimulation, and the failure of old males to increase activity after TRH injections may be due to a loss of the thyroid's ability to respond to direct TRH stimulation.
Gen Comp Endocrinol 1983 Apr
PMID:Age-related changes in pituitary/thyroid function in chickens. 630 97

Preparations of purified poliovirus type 1, strain Mahoney, and empty viral capsids contain a protein kinase activity. The gamma-phosphoryl group of [32P]ATP is transferred to all of the capsid proteins. Viral proteins phosphorylated in vitro are recognized by antiserum directed against isolated viral capsid proteins, indicating that phosphorylation does not alter the antigenic sites to such an extent that the recognition by antibodies is abolished. Viral capsid protein phosphorylation exposes new antigenic sites and leads to a destabilization of the virions. The transfer of 32P to viral proteins is linear for 90 min at 37 degrees C in the presence of 10 mM-Mg2+ at pH 8.1. Reducing agents or virus-stabilizing agents (such as arildone) reduce the kinase activity and result in a different pattern of capsid protein phosphorylation.
J Gen Virol 1984 Jan
PMID:Protein kinase activity in purified poliovirus particles and empty viral capsid preparations. 631 65


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