Singh I N, Dakshinamurti K
Department of Biochemistry, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
Mol Cell Biochem. 1988 Jan;79(1):47-55. doi: 10.1007/BF00229397.
HeLa cells cultured in a biotin-deficient medium showed reduced rates of protein synthesis, DNA synthesis and growth. Continuous synthesis is required for the increase in DNA synthesis observed upon addition of biotin to cells cultured in biotin-deficient medium. The addition of biotin to the biotin-deficient culture medium increased the activity of guanylate cyclase in both HeLa cells and fibroblasts. Both cell types cultured in biotin deficient medium showed reduced activity of RNA Polymerase II. The exogenous addition of biotin to the biotin-deficient cell cultures also resulted in increased activity of RNA Polymerase II in HeLa cells and fibroblasts. The maximal response was observed in 4 hours. Significant increase in enzyme activity was observed at 10(-8) M biotin in the culture medium. The growth promoting effect of biotin seems to involve stimulations of cellular guanylate cyclase and RNA Polymerase II activity.
在生物素缺乏培养基中培养的HeLa细胞，其蛋白质合成、DNA合成和生长速率均降低。在生物素缺乏培养基中培养的细胞，添加生物素后观察到DNA合成增加，这需要持续合成。向生物素缺乏的培养基中添加生物素，可增加HeLa细胞和成纤维细胞中鸟苷酸环化酶的活性。在生物素缺乏培养基中培养的两种细胞类型均显示RNA聚合酶II的活性降低。向生物素缺乏的细胞培养物中外源添加生物素，也会导致HeLa细胞和成纤维细胞中RNA聚合酶II的活性增加。在4小时时观察到最大反应。在培养基中生物素浓度为10(-8) M时，观察到酶活性显著增加。生物素的生长促进作用似乎涉及对细胞鸟苷酸环化酶和RNA聚合酶II活性的刺激。
