gamma-Glutamylcysteine synthetase and active transport of glutathione S-conjugate are responsive to heat shock in K562 erythroid cells.
gamma-Glutamylcysteine synthetase and active transport of glutathione S-conjugate are responsive to heat shock in K562 erythroid cells.
复制标题
DOI：
--
复制
发表时间：
1993-09
期刊：
影响因子：
--
通讯作者：
T. Kondo;K. Yoshida;Y. Urata;S. Goto;S. Gasa;N. Taniguchi
中科院分区：
文献类型：
--
作者：
T. Kondo;K. Yoshida;Y. Urata;S. Goto;S. Gasa;N. Taniguchi
热休克对谷胱甘肽合成酶γ -谷氨酰半胱氨酸合成酶（γ - gcs）的影响，以及atp依赖的谷胱甘肽s -缀合物的外转运。将37℃培养的K562细胞转移到42℃培养2小时，观察到γ - gcs活性增加了约1.7倍。用促红细胞生成素（EP）处理K562细胞12小时后，γ - gcs活性下降至对照组的64%。然而，经EP处理的细胞对热休克的反应性与未处理的细胞相似。γ - gcs免疫活性的变化与酶活性的变化是平行的。Northern blot分析了人类γ - gcs cDNA细胞中分离的总rna，发现热休克和EP降低显著诱导mRNA水平。这些变化不大，但与热休克蛋白hsp70的mRNA表达有关。热休克对1-氯-2,4-二硝基苯培养的K562细胞的谷胱甘肽s缀合物转运也有1.8倍的刺激作用。用EP处理细胞导致这种转运减少62%。同样，谷胱甘肽s -缀合物刺激的Mg(2+)- atp酶的水平，被认为参与谷胱甘肽s -缀合物的运输，对热休克和EP有反应。这些结果表明，谷胱甘肽的合成和谷胱甘肽代谢物的转运过程对热休克有反应，并在应激防御系统中发挥作用。这也表明热休克对这些酶的表达的调控位点是独立于EP的。
Effect of heat shock on a glutathione-synthesizing enzyme, gamma-glutamylcysteine synthetase (gamma-GCS), and ATP-dependent outward transport of glutathione S-conjugate was characterized using K562 erythroid cells. When K562 cells grown at 37 degrees C were shifted to 42 degrees C for 2 h, an approximate 1.7-fold increase in the activity of gamma-GCS was observed. Treatment of K562 cells with erythropoietin (EP) for 12 h resulted in a decrease in the activity of gamma-GCS to 64% of the control. However, responsiveness of this enzyme activity in the cells treated with EP to heat shock was similar to that in untreated cells. Changes in the immunological activity of gamma-GCS were also observed in parallel with those in the enzymatic activity. On Northern blot analysis of total RNAs isolated from the cells with human cDNA for gamma-GCS, a substantial induction of mRNA level was found by heat shock and a reduction of EP. These changes were modest but correlated to the mRNA expression of a heat shock protein, HSP 70. Heat shock also had an effect of 1.8-fold stimulation on glutathione S-conjugate transport in K562 cells previously incubated with 1-chloro-2,4-dinitrobenzene. Treatment of the cells with EP resulted in a decrease in this transport by 62%. Similarly, the levels of glutathione S-conjugate-stimulated Mg(2+)-ATPase, which enzyme is thought to be involved in the transport of glutathione S-conjugate, were responsive to heat shock and EP. These results suggest that glutathione synthesis and transport process of glutathione metabolites are responsive to heat shock and play a role in the defense system against stresses. It is also suggested that the regulatory site of the expression of these enzymes by heat shock is independent of that by EP.