Gaudreau L, Adam M, Ptashne M
Program in Molecular Biology, Memorial Sloan-Kettering Cancer Institute, New York, New York 10021, USA.
Mol Cell. 1998 May;1(6):913-6. doi: 10.1016/s1097-2765(00)80090-8.
It has been argued that many transcriptional activators work by "recruitment," that is, by helping the transcriptional machinery bind stably to DNA. We demonstrate here a realization of a strong prediction of this idea in an in vitro transcription reaction performed with purified yeast RNA polymerase II holoenzyme and a classical transcriptional activator. We show that the level of transcription reached by the activator working on low concentrations of holoenzyme can also be reached in the absence of activator by raising the holoenzyme concentration, and that under that condition the activator has no further stimulatory effect. We also show, in agreement with another prediction of the recruitment model, that in a reaction using a holoenzyme purified from cells bearing the "P" mutation, transcription is stimulated by a DNA-tethered peptide that binds the mutant holoenzyme component Gal11P but that lacks a classical activating region.
有人认为，许多转录激活因子通过“募集”发挥作用，也就是说，通过帮助转录机制稳定地结合到DNA上。我们在此证明，在使用纯化的酵母RNA聚合酶II全酶和经典转录激活因子进行的体外转录反应中，这一观点的一个有力预测得到了证实。我们表明，在低浓度全酶条件下发挥作用的激活因子所达到的转录水平，在没有激活因子的情况下通过提高全酶浓度也能达到，并且在该条件下激活因子没有进一步的刺激作用。我们还表明，与募集模型的另一个预测一致，在使用从携带“P”突变的细胞中纯化的全酶进行的反应中，一种与突变的全酶成分Gal11P结合但缺乏经典激活区域的DNA连接肽可刺激转录。
