In vitro evidence that eukaryotic ribosomal RNA transcription is regulated by modification of RNA polymerase I.
In vitro evidence that eukaryotic ribosomal RNA transcription is regulated by modification of RNA polymerase I.
复制标题
体外证据表明真核核糖体 RNA 转录受 RNA 聚合酶 I 修饰的调节。
DOI：
10.1093/nar/12.21.8161
复制
发表时间：
1984
影响因子：
14.9
通讯作者：
D'Alessio,JM
中科院分区：
文献类型：
--
作者：
Paule,MR;Iida,CT;Perna,PJ;Harris,GH;Knoll,DA;D'Alessio,JM
我们利用一个来自阿米巴的无细胞转录系统检测了RNA聚合酶I和转录起始因子I（TIF-I）在发育过程中下调rRNA转录的功能活性。这些结果有力地表明，rRKA的转录受RKA聚合酶I的修饰（可能是共价修饰）的调节：（1）转录活性细胞和非转录活性细胞提取物中TIF-I的活性水平是恒定的。(2)在转录活跃和不活跃的细胞中RNA聚合酶I分子的数量也是恒定的。(3)相反，虽然聚合酶I对受损模板的特异性活性保持不变，但来自失活细胞的粗品和纯化的聚合酶I都失去了参与rRNA转录忠实起始的能力。(4)从转录活性细胞纯化的聚合酶I具有与来自非活性细胞的酶相同的亚基结构。然而，后者的热变性速度比活性聚合酶快5倍。
We have utilized a cell-free transcription system fromAcanthamoebacastellaniito test the functional activity of RNA polymerase I and transcription initiation factor I (TIF-I) during developmental down regulation of rRNA transcription. The results strongly suggest that rRKA transcription is regulated by modification, probably covalent, of RKA polymerase I: (1) The level of activity of TIF-I in extracts from transcriptionally active and inactive cells is constant. (2) The number of RNA polymerase I molecules in transcriptionally active and inactive cells is also constant. (3) In contrast, though the specific activity of polymerase I on damaged templates remains constant, both crude and purified polymerase I from inactive cells have lost the ability to participate in faithful initiation of rRNA transcription. (4) Polymerase I purified from transcriptionally active cells has the same subunit architecture as enzyme from inactive cells. However, the latter is heat denatured 5 times faster than the active polynerase.