P-31 NMR-STUDIES OF INTRACELLULAR PH AND PHOSPHATE-METABOLISM DURING CELL-DIVISION CYCLE OF SACCHAROMYCES-CEREVISIAE
P-31 NMR-STUDIES OF INTRACELLULAR PH AND PHOSPHATE-METABOLISM DURING CELL-DIVISION CYCLE OF SACCHAROMYCES-CEREVISIAE
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DOI：
10.1073/pnas.78.4.2125
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发表时间：
1981-01-01
期刊：
影响因子：
--
通讯作者：
SHULMAN, RG
中科院分区：
文献类型：
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作者：
GILLIES, RJ;UGURBIL, K;SHULMAN, RG
利用高分辨31P核磁共振波谱分析了酿酒酵母(NCyC239)细胞周期中细胞内pH和磷代谢的变化。高密度酵母菌培养(2倍。108细胞/毫升)，在开始之前通过顺序葡萄糖剥夺停止，之后它们同步复制DNA，并在最后一次葡萄糖喂养后分裂。在没有葡萄糖的情况下，停滞培养物的氧合导致糖、磷酸和三磷酸腺苷水平的增加，以及细胞内pH的增加。这些条件没有启动细胞周期进程，表明能量不被用作启动细胞分裂周期的细胞内信号，细胞需要外源C源来生长。只有在同步培养中，葡萄糖再补给才会引起碱性胞内pH瞬变；胞内pH的升高伴随着START的穿越。在同步培养中，观察到了磷酸盐流动和利用的变化。在DNA合成过程中，外部磷酸盐的消耗增加。当外部磷酸盐水平较低时，细胞会消耗其内部的聚磷酸盐储存。在这种情况下，聚磷酸盐显然起到了磷酸盐供应的作用。
Changes in intracellular pH and phosphate metabolism during the cell cycle of S. cerevisiae (NCYC 239) were analyzed by using high-resolution 31P NMR spectroscopy. High-density yeast cultures (2 .times. 108 cells/ml) were arrested prior to start by sequential glucose deprivation, after which they synchronously replicated DNA and divided after a final glucose feeding. Oxygenation of arrested cultures in the absence of glucose led to increased levels of sugar phosphates and ATP and an increase in intracellular pH. These conditions did not initiate cell cycle progression indicating that energization is not used as an intracelllular signal for initiation of the cell division cycle and that the cells need exogenous C sources for growth. Glucose refeeding initiated an alkaline intracellular pH transient only in the synchronous cultures; increased intracellular pH accompanies the traversal of start. Changes in phosphate flow and utilization were observed in the synchronous cultures. There was increased consumption of external phosphate during DNA synthesis. When external phosphate levels were low, the cells consumed their internal polyphosphate stores. Under these conditions polyphosphate apparently acts as a phosphate supply.