Dobson M E, Ingram V M
Nucleic Acids Res. 1980 Sep 25;8(18):4201-19. doi: 10.1093/nar/8.18.4201.
The culture of cells in the presence of sodium n-butyrate causes an accumulation of histones that are highly acetylated. When chromatin containing these histones was transcribed with E. coli RNA polymerase, an increase in the template activity compared to control chromatin was observed. Titration of chromatin with polymerase under both reinitiating and non-reinitiating conditions showed there was no increase in the number of regions available for transcription. Comparison of the kinetics for single and multiple rounds of transcription indicated that the rate of elongation was increased and probably the rate of reinitiation as well. Comparison of the size of transcripts from control and acetylated chromatin showed a small increase in the average size of transcripts from acetylated chromatin. When transcription was compared using partially purified HeLa polymerase, an increase was also seen. Studies under various ionic conditions showed that control chromatin required a higher salt concentration for optimum activity than did acetylated chromatin. In addition, at the optimum salt concentration for each chromatin, there was very little difference in the transcriptional activity using exogenous HeLa RNA polymerase.
在丁酸钠存在的情况下培养细胞会导致高度乙酰化组蛋白的积累。当用大肠杆菌RNA聚合酶转录含有这些组蛋白的染色质时，与对照染色质相比，观察到模板活性增加。在重新起始和非重新起始条件下用聚合酶对染色质进行滴定表明，可用于转录的区域数量没有增加。单轮和多轮转录动力学的比较表明，延伸速率增加，重新起始速率可能也增加。对照染色质和乙酰化染色质转录本大小的比较表明，乙酰化染色质转录本的平均大小略有增加。当使用部分纯化的HeLa聚合酶进行转录比较时，也观察到了增加。在各种离子条件下的研究表明，对照染色质比乙酰化染色质需要更高的盐浓度才能达到最佳活性。此外，在每种染色质的最佳盐浓度下，使用外源HeLa RNA聚合酶时转录活性的差异很小。
