EVIDENCE FOR GENETIC-CONTROL OF SODIUM-PUMP DENSITY IN HELA-CELLS
EVIDENCE FOR GENETIC-CONTROL OF SODIUM-PUMP DENSITY IN HELA-CELLS
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DOI：
10.1113/jphysiol.1974.sp010684
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发表时间：
1974-01-01
影响因子：
5.5
通讯作者：
POLSON, JM
中科院分区：
文献类型：
--
作者：
BOARDMAN, L;HUETT, M;POLSON, JM
1. HeLa细胞在正常和改变的生长溶液中生长；测量离子含量、体积、K敏感哇巴因结合、Na-K-ATP酶以及Na和K转运。2．在 1 × 10−4Methacrynate 或低 K 培养基中生长 24 小时的细胞，[Na]i 升高，[K]i 降低，哇巴因结合增加。在低 K 条件下生长的 Na-K-ATP 酶活性也有所增加。3。当细胞被放入低 K 溶液中时，[Na]i 最初上升到一个高值，然后随着哇巴因结合的增加大约 8 小时后开始下降，表明这些额外的位点代表了正在工作的 Na 泵。低 K 电池的通量测量为这一观点提供了一些支持。4。山梨醇取代[Na]o的实验表明，哇巴因结合和Na-K-ATP酶的增加与[Na]的增加而不是[K]i的减少有关，并且不是由于[K]o变化的非特异性效应。5。蛋白质合成抑制剂放线菌酮和嘌呤霉素阻止了依他尼酸盐和低 K 溶液对哇巴因结合增加的影响。他们还在 24 小时内减少了正常细胞中哇巴因的结合和钾离子的流入。放线菌酮对低 K 处理细胞和正常细胞中的 Na-K-ATP 酶具有相似的作用。这些结果表明，细胞膜上出现更多哇巴因敏感位点需要蛋白质合成，无论是对依他尼酸盐和低 K 处理的反应，还是细胞生命过程中的正常替换。6。 RNA 合成抑制剂放线菌素 D (AMD) 和虫草素对新鲜和依他尼酸盐处理的细胞中哇巴因的结合具有复杂的影响。这些抑制剂增加了哇巴因的结合，但减少了钾离子的流入。这种差异是由于哇巴因结合位点的出现与正常位点具有不同的特征。对这一现象进行了有限的调查。 AMD 可能会停止膜中位点的正常更换。7。这些结果与 HeLa 细胞具有控制膜中 Na 泵数量的系统的假设一致。该系统对细胞内的[Na]i水平做出反应并涉及蛋白质合成。目前尚不清楚细胞核通常在多大程度上参与这一过程。
1. HeLa cells were grown in normal and altered growth solutions; the ion contents, volumes, K sensitive ouabain binding, the Na‐K‐ATPase and the Na and K transport measured.2. Cells grown in 1 × 10−4Methacrynate or low‐K media for 24 hr have a raised [Na]i, a decreased [K]i, and an increased ouabain binding. Those grown in low‐K also have an increased Na‐K‐ATPase activity.3. When cells are put into low‐K solutions the [Na]iinitially rises to a high value, and then starts to fall some 8 hours later as the ouabain binding increases, suggesting that these additional sites represent working Na pumps. Flux measurements on low‐K cells provide some support for this view.4. Experiments in which sorbitol replaced [Na]oshowed that the increased ouabain binding and Na‐K‐ATPase was related to the increase in [Na]irather than the decrease in [K]iand was not due to a non‐specific effect of [K]ochange.5. The protein synthesis inhibitors cycloheximide and puromycin stopped the effect of ethacrynate and low‐K solutions on increased ouabain binding. They also decreased the ouabain binding and K influx in normal cells over 24 hr. Cycloheximide had similar effects on Na‐K‐ATPase in low‐K treated and normal cells. These results suggest that protein synthesis is required for the appearance of more ouabain sensitive sites in the cell membrane, both in response to ethacrynate and low‐K treatment and for normal replacement during the cell's life.6. The RNA synthesis inhibitors actinomycin D (AMD) and cordycepin had complex effects on ouabain binding in fresh and ethacrynate treated cells. These inhibitors increased the ouabain binding but decreased the K influx. This discrepancy was due to the appearance of ouabain binding sites with different characteristics from normal sites. A limited investigation of this phenomenon was carried out. Probably AMD stops the normal replacement of sites in the membrane.7. These results are consistent with the hypothesis that HeLa cells have a system for controlling the number of Na pumps in their membranes. This system responds to the level of [Na]iwithin the cell and involves protein synthesis. It is not clear to what extent the nucleus is normally involved in this process.