Effect of NaF and okadaic acid on the subcellular distribution of CTP: phosphocoline cytidylyltransferase activity in rat liver
| Autor: | Dennis E. Vance, Grant M. Hatch, Y. Tsukitani, Tsz-Shan Lam |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Time Factors
Cytidylyltransferase Biophysics Biochemistry Choline-phosphate cytidylyltransferase chemistry.chemical_compound Endocrinology Ethers Cyclic Okadaic Acid Animals Choline-Phosphate Cytidylyltransferase Phosphorylation chemistry.chemical_classification Okadaic acid Alkaline Phosphatase Nucleotidyltransferases Cytidylyltransferase activity Rats Enzyme Activation Cytosol Enzyme Liver chemistry Microsome Sodium Fluoride Cell fractionation Subcellular Fractions |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 1042:374-379 |
| ISSN: | 0005-2760 |
| DOI: | 10.1016/0005-2760(90)90167-v |
| Popis: | The effect of preincubation of rat liver post-mitochondrial supernatant with NaF and okadaic acid on the subcellular distribution of CTP: phosphocholine cytidylyltransferase activity was investigated. NaF (20 mM) inhibited the time-dependent activation of cytidylyltransferase activity in post-mitochondrial supernatant. Subcellular fractionation of the post-mitochondrial supernatant revealed that cytidylyltransferase activity in the microsomal fraction was decreased and activity in the cytosolic fraction increased with time of preincubation with NaF compared to controls. Okadaic acid is a specific and potent inhibitor of type 1 and 2A phosphoprotein phosphatases. Preincubation of cytosol with 5 microM okadaic acid inhibited the time-dependent activation of cytosolic cytidylyltransferase activity. Preincubation of post-mitochondrial supernatants with 5 microM okadaic acid inhibited the time-dependent activation of cytidylyltransferase activity by 13% at 45 min and 16% at 60 min of preincubation compared to controls. Microsomal cytidylyltransferase activity was decreased 27% at 45 min and 31% at 60 min with a corresponding retention of cytosolic cytidylyltransferase activity of 21% at 45 min and 37% at 60 min of preincubation with okadaic acid compared to controls. We postulate that the activity of the type 1 and/or type 2A phosphoprotein phosphatases affect the subcellular distribution of CTP: phosphocholine cytidylyltransferase activity in rat liver. |
| Databáze: | OpenAIRE |
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