Thymidine transport in phytohaemagglutinin-stimulated pig lymphocytes
| Autor: | Barlow, S D, Ord, M G |
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| Zdroj: | Biochemical Journal; May 1975, Vol. 148 Issue: 2 p295-302, 8p |
| Abstrakt: | Thymidine and uridine transporters in peripheral pig lymphocytes have structural features in common, but are not identical. Accelerated entry of [3H]thymidine begins 12h after the addition of phytohaemagglutinin. The increased thymidine uptake into the cells is characterized by an increase in Vmax. Without alteration of the apparent Km(0.6+/-0.08muM). Thymidine kinase activity is increased 12h after stimulation. Both the increased thymidine uptake and the increased thymidine kinase activity are inhibited in cultures incubated with puromycin: rates of degradation of the two systems are unchanged after phytohaemagglutinin addition, and indicate similar half-lives of about 2h. Thymidine kinase is rate-limiting for thymidine entry up to 18h after phytohaemagglutinin addition; increase in its synthesis is detectable about 6h before net incorporation of thymidine into DNA is significantly promoted. |
| Databáze: | Supplemental Index |
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