硫酸化多糖对小鼠肾脏染色质转录的刺激作用。
Stimulation of transcription of mouse kidney chromatin by sulfated polysaccharides.
作者信息
Warnick C T, Zazarus H M
出版信息
Nucleic Acids Res. 1975 May;2(5):735-44. doi: 10.1093/nar/2.5.735.
The sulfated polysaccharides polydextran sulfate (PDS) and heparin stimulate in vitro transcription of mouse kidney chromatin by E. coli RNA polymerase by about 100 and 40 fold respectively. Heparin which has been N-desulfated and N-acetylated stimulates only 13 fold. Chondroitin sulfate B and heparitin sulfate do not stimulate transcription under similar conditions. PDS inhibits transcription of deproteinized chromatin. Therefore, the stimulation with chromatin is due to interaction with the chromatin and not the polymerase. Polydextran sulfate has no effect on the size of the RNA that is made either under conditions in which the enzyme can reinitiate or under conditions in which reinitiation is blocked. If reinitiation of the enzyme is blocked, the time required to complete the synthesis of the RNA is the same whether or not the enzyme is stimulated by PDS. These observations indicate that sulfated polysaccharides stimulate transcription by making available new RNA polymerase binding sites on the chromatin.
硫酸化多糖聚葡聚糖硫酸酯（PDS）和肝素分别能使大肠杆菌RNA聚合酶对小鼠肾脏染色质的体外转录活性提高约100倍和40倍。经过N - 去硫酸化和N - 乙酰化处理的肝素仅能使转录活性提高13倍。在类似条件下，硫酸软骨素B和硫酸类肝素不能刺激转录。PDS抑制脱蛋白染色质的转录。因此，对染色质的刺激作用是由于与染色质相互作用，而非与聚合酶相互作用。无论在酶可重新起始转录的条件下，还是在重新起始被阻断的条件下，聚葡聚糖硫酸酯对所合成RNA的大小均无影响。如果酶的重新起始被阻断，无论酶是否受到PDS刺激，完成RNA合成所需的时间是相同的。这些观察结果表明，硫酸化多糖通过在染色质上提供新的RNA聚合酶结合位点来刺激转录。
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