Abstract
Protein kinase C modulates the activity of a highly specific uptake mechanism for queuine in cultured human fibroblasts. Activators of protein kinase C induce an increased uptake rate for the radiolabeled analog of queuine, rQT3. The protein kinase C inhibitors, H-7, staurosporine and sphingosine all induced a dramatic decrease in the uptake rate of rQT3. This suggests that protein kinase C is tied to efficient cellular uptake of queuine. Uptake is prerequisite to the modification of transfer RNA with queuine. Perturbation of queuine-modified transfer RNA levels has been associated with neoplastic transformation, differentiation and growth control.
MeSH terms
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
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Alkaloids / pharmacology
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Calcimycin / pharmacology
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Cells, Cultured
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Diglycerides / pharmacology
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Enzyme Activation / drug effects
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Fibroblasts / metabolism
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Growth Substances / pharmacology
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Guanine / analogs & derivatives*
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Guanine / metabolism
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Humans
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In Vitro Techniques
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Isoquinolines / pharmacology
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Male
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Phorbol Esters / pharmacology
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Phosphatidylserines / pharmacology
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Piperazines / pharmacology
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Protein Kinase C / physiology*
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Sphingosine / pharmacology
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Staurosporine
Substances
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Alkaloids
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Diglycerides
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Growth Substances
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Isoquinolines
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Phorbol Esters
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Phosphatidylserines
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Piperazines
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phorbol-12,13-didecanoate
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Calcimycin
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Guanine
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queuine
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
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Protein Kinase C
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Staurosporine
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Sphingosine
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diolein