Gonzalez Fernando, Delahodde Agnes, Kodadek Thomas, Johnston Stephen Albert
Center for Biomedical Inventions, University of Texas-Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8573, USA.
Science. 2002 Apr 19;296(5567):548-50. doi: 10.1126/science.1069490.
The 19S proteasome regulatory particle plays a critical role in cellular proteolysis. However, recent reports have demonstrated that 19S proteins play a nonproteolytic role in nucleotide excision repair and transcription elongation. We show by chromatin immunoprecipitation assays that proteins comprising the 19S complex are recruited to the GAL1-10 promoter by the Gal4 transactivator upon induction with galactose. This recruited complex does not contain proteins from the 20S proteolytic particle and includes a subset of the 19S proteins. This subset is also specifically retained from an extract by the Gal4 activation domain. These data indicate that in vivo, the base of the 19S complex functions independently of the larger complex and plays a direct, nonproteolytic role in RNA polymerase II transcription.
19S蛋白酶体调节颗粒在细胞蛋白水解中起关键作用。然而，最近的报道表明，19S蛋白在核苷酸切除修复和转录延伸中发挥非蛋白水解作用。我们通过染色质免疫沉淀试验表明，在用半乳糖诱导后，由Gal4反式激活因子将组成19S复合物的蛋白募集到GAL1-10启动子上。这种募集到的复合物不包含来自20S蛋白水解颗粒的蛋白，并且包括19S蛋白的一个子集。该子集也被Gal4激活域从提取物中特异性保留。这些数据表明，在体内，19S复合物的基部独立于更大的复合物发挥作用，并在RNA聚合酶II转录中发挥直接的非蛋白水解作用。
