Protein Kinases Associated with the Adenovirus Single‐Stranded DNA‐Binding Protein

Cajean-Feroldi, Chantal; Loeb, Jacques; Meguenni, S; Girard, Mare

doi:10.1111/j.1432-1033.1981.tb05672.x

Cited by 4 publications

(3 citation statements)

References 49 publications

(28 reference statements)

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“…Some exogenous substrate proteins stimulated the phosphorylation of viral capsid proteins to different extents. This has been shown previously for other virus associated kinases (2,3,9,32). While histone III S was phosphorylated, it showed no stimulatory effect on the phosphorylation of viral capsid proteins.…”

Section: Phosphorylation Of Non-viral Substrate Protein~supporting

confidence: 86%

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Properties of poliovirus associated protein kinase

Lackmann

Ueckermann

Engelmann

et al. 1987

Archives of Virology

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Highly purified virulent poliovirus preparations harbour an endogenous protein kinase. Enzyme activity increases significantly upon purification of infectious virus particles from infected HeLa cells. Enzyme activity is stimulated by divalent cations. The substrate specificity and the degree of stimulation of the kinase are dependent on the nature of the divalent cations included in the assay. The preferred substrates for this kinase are the viral capsid proteins. Exogenously added proteins such as alpha-casein, phosvitin and protamine are also phosphorylated by the kinase. Moreover, these proteins enhance the phosphorylation of viral proteins. In the presence of Mg++ VP 2 and VP 0 are highly phosphorylated, while in the presence of Zn++ only VP 2 and VP 4, but not VP 0 or exogenous proteins are phosphorylated. Poliovirus associated protein kinase exhibits optimal activity at pH 7.9 in the presence of 10 mM Mg++. The Km for ATP is shown to be 40 microM. By testing different nucleotides as phosphate donors a specificity of the phosphorylation reaction for ATP is demonstrated. Phosphoamino acid analysis of hydrolysates of the substrates phosphorylated in the presence of Mg++ by thin layer electrochromatography and HPLC yielded phosphoserine and phosphothreonine from viral capsid proteins while hydrolysates of protamine yield only phosphoserine. Destabilization of the viral capsid, e.g. by preincubation at 42 degrees C for 20 minutes results in a stimulation of kinase activity. Moreover, phosphorylation of the poliovirus capsid proteins itself results in destabilization of the viral capsid. These findings suggest that phosphorylation of the viral coat proteins triggers or enhances the uncoating of poliovirus leading to the release of viral RNA.

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Section: Phosphorylation Of Non-viral Substrate Protein~supporting

confidence: 86%

“…5 e). As shown previously for many virus associated protein kinases (2,3,9,31,32), enzyme activity is stimulated in the presence of some substrate proteins, e.g. by protamine.…”

Section: Discussionsupporting

confidence: 70%

Properties of poliovirus associated protein kinase

Lackmann

Ueckermann

Engelmann

et al. 1987

Archives of Virology

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“…Viral capsid proteins are the preferred substrates for virus-associated kinase. The enzyme activity shares characteristics in common with other virus-associated protein kinases, such as stimulation of enzyme activity by the divalent cation Mg2+, inhibition of enzyme activity by high concentrations of Zn2+, phosphorylation of some common phosphate acceptor proteins (i.e., protamine, x-casein, histone, and phosvitin), and specificity of the enzyme for serine and threonine residues as phosphate acceptor sites (1,8,10,13,19,23,26). Phosphorylated virus particles have altered immunoreactivity and, in contrast to native virus particles, are sensitive to 1% sodium dodecyl sulfate (SDS) (25).…”

mentioning

confidence: 96%

Poliovirus-associated protein kinase: destabilization of the virus capsid and stimulation of the phosphorylation reaction by Zn2+

Ratka

Lackmann

Ueckermann

et al. 1989

J Virol

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The previously described poliovirus-associated protein kinase activity phosphorylates viral proteins VPO and VP2 as well as exogenous proteins in the presence of Mg2+. In this paper, the effect of Zn2+ on the phosphorylation reaction and the stability of the poliovirus capsid has been studied in detail and compared to that of Mg2+. Phosphorylation patterns of viral and other proteins depend on the divalent cation present. In the presence of Zn2+, phosphorylation of capsid proteins VP2 and VP4 is significantly higher while phosphorylation of VPO and exogenous phosphate acceptor proteins is not detected. Our results indicate the activation of more than one virus-associated protein kinase by Zn2+. The ion-dependent behavior of the enzyme activities is observed independently of whether the virus was obtained from HeLa or green monkey kidney cells. The poliovirus capsid is destabilized by Zn2+. The destabilization leads to a substantially increased permeability of virus particles to ethidium bromide and RNase, concomitant with decreased infectivity of the sample. This alteration of the poliovirus capsid structure is a prerequisite for effective phosphorylation of viral capsid proteins. The increased level of phosphorylation of viral capsid proteins results in further destabilization of the viral capsid. As a result of the conformational changes, poliovirus-associated protein kinase activities dissociate from the virus particle. High-performance liquid chromatography-purified viral protein VP2 is phosphorylated by the released enzymes on serine, threonine, and tyrosine in the presence of Zn2+. We suggest that the destabilizing effect of phosphorylation on the viral capsid plays a role in uncoating of poliovirus.

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Protamine inhibits platelet derived growth factor receptor activity but not epidermal growth factor activity

Huang

Nishimura

Huang

et al. 1984

J of Cellular Biochemistry

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Protamine sulfate blocked 125I-PDGF binding to its specific physiological receptor on Swiss mouse 3T3 cells. Reduced 125I-PDGF binding in the presence of protamine sulfate correlated directly with a protamine sulfate dose-dependent decrease in the PDGF-dependent incorporation of [3H]-thymidine into 3T3 cells and a decreased PDGF-stimulated tyrosine-specific protein kinase activity in isolated membrane preparations of 3T3 cells. Protamine sulfate blocked 125I-PDGF binding to simian sarcoma virus transformed cells (SSV-NIH 3T3 and SSV-NP1 cells) and to nontransformed cells in a manner qualitatively identical to unlabelled PDGF. In contrast, protamine sulfate enhanced the specific binding of 125I-EGF by increasing the apparent number of EGF receptors on the cell surface. The increase in 125I-EGF receptor binding was not prevented by cycloheximide nor by actinomycin D. Protamine sulfate did not affect 125I-EGF binding to membranes from 3T3 cells or the EGF-stimulated 3T3 cell membrane tyrosine specific protein kinase activity, suggesting that protamine sulfate may have exposed a population of cryptic EGF receptors otherwise not accessible. Protamine sulfate was fractionated into four active fractions by Sephadex G-50 gel filtration columns; the half maximum inhibition concentration of 125I-PDGF binding to 3T3 cells of protamines I and II (MW approximately 11,000 daltons and 7,000 daltons, respectively) is approximately 0.4 microM. Protamine II (MW approximately 4,800 daltons) was equally active (half maximum inhibition concentration approximately 0.4 microM); protamine IV (MW approximately 3,300 daltons) was substantially less active (half maximum inhibition concentration approximately 2.8 microM). These investigations have extended previous observations that protamine sulfate is a potent inhibitor of PDGF binding and establish that protamine sulfate blocks PDGF binding at the physiological receptor, preventing PDGF initiated biological activities. Protamine sulfate can be used as a reagent to separate the influence of PDGF and EGF on cells with high specificity and has been used to demonstrate that the receptors on simian sarcoma virus transformed 3T3 cells qualitatively respond identically to protamine sulfate as to unlabelled PDGF and are likely identical to those on nontransformed 3T3 cells.

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Protein Kinases Associated with the Adenovirus Single‐Stranded DNA‐Binding Protein

Cited by 4 publications

References 49 publications

Properties of poliovirus associated protein kinase

Properties of poliovirus associated protein kinase

Poliovirus-associated protein kinase: destabilization of the virus capsid and stimulation of the phosphorylation reaction by Zn2+

Protamine inhibits platelet derived growth factor receptor activity but not epidermal growth factor activity

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