Marchand M J, Maisin L, Hue L, Rousseau G G
Hormone and Metabolic Research Unit, University of Louvain Medical School, Brussels, Belgium.
Biochem J. 1992 Jul 15;285 ( Pt 2)(Pt 2):413-7. doi: 10.1042/bj2850413.
6-Phosphofructo-2-kinase (PFK-2) catalyses the synthesis of fructose 2,6-bisphosphate (Fru-2,6-P2), a potent stimulator of glycolysis. In chick-embryo fibroblasts, PFK-2 activity and Fru-2,6-P2 concentration increase upon transformation by Rous sarcoma virus. We show here that the increase in PFK-2 activity required more than 2 h after shifting fibroblasts infected with a thermosensitive mutant of Rous sarcoma virus from the restrictive to the permissive temperature. Pretreatment of the cells with actinomycin D prevented this increase in PFK-2 activity, suggesting a requirement for RNA synthesis. However, the increase in PFK-2 activity did not correspond to an increase in immunoprecipitable PFK-2. Moreover, the thermostability of PFK-2 and the affinity of this enzyme for its substrate fructose 6-phosphate were increased upon transformation by Rous sarcoma virus. Staurosporine, an inhibitor of protein kinase C, prevented the increase in PFK-2 activity brought about by the shift to the permissive temperature. This, together with a comparison of the effects of phorbol esters on PFK-2 activity, suggests that pp60v-src stimulates, via protein kinase C, the transcription of a gene whose products is a distinct PFK-2 isoenzyme or a protein that activates PFK-2.
6-磷酸果糖-2-激酶（PFK-2）催化果糖2,6-二磷酸（Fru-2,6-P2）的合成，Fru-2,6-P2是糖酵解的一种有效刺激物。在鸡胚成纤维细胞中，劳斯肉瘤病毒转化后PFK-2活性和Fru-2,6-P2浓度会增加。我们在此表明，将感染了劳斯肉瘤病毒温度敏感突变体的成纤维细胞从限制温度转移到允许温度后，PFK-2活性增加需要超过2小时。用放线菌素D预处理细胞可阻止PFK-2活性的这种增加，这表明需要RNA合成。然而，PFK-2活性的增加与免疫沉淀的PFK-2增加并不对应。此外，劳斯肉瘤病毒转化后，PFK-2的热稳定性及其对底物6-磷酸果糖的亲和力增加。蛋白激酶C抑制剂星形孢菌素可阻止因转移到允许温度而导致的PFK-2活性增加。这一点，再加上佛波酯对PFK-2活性影响的比较，表明pp60v-src通过蛋白激酶C刺激一个基因的转录，该基因的产物是一种不同的PFK-2同工酶或一种激活PFK-2的蛋白质。
