Innes Fiona, Ramsbottom Ben, White Robert J
Institute of Biomedical and Life Sciences, Division of Biochemistry and Molecular Biology, University of Glasgow, Glasgow G12 8QQ, UK.
Nucleic Acids Res. 2006 Jul 5;34(11):3399-407. doi: 10.1093/nar/gkl432. Print 2006.
TFIIIC is a RNA polymerase (pol) III-specific DNA-binding factor that is required for transcription of tRNA and 5S rRNA genes. Active human TFIIIC consists of five subunits. However, an inactive form has also been isolated that lacks one of the five subunits, called TFIIIC110. A model was proposed in which pol III transcription might be regulated by the specific induction of TFIIIC110, allowing formation of active TFIIIC from the inactive form. We have tested this model by transient transfection of HeLa and HEK293 cells with a vector expressing TFIIIC110. We have also made stably transfected HeLa cell lines that carry a doxycycline-inducible version of the cDNA for TFIIIC110. We show that the induced TFIIIC110 enters the nucleus, binds other TFIIIC subunits and is recruited to tRNA and 5S rRNA genes in vivo. However, little or no effect is seen on the expression of pol III transcripts. The data argue against the model that pol III transcription can be effectively modulated through the specific induction of TFIIIC110.
TFIIIC是一种RNA聚合酶（pol）III特异性DNA结合因子，是tRNA和5S rRNA基因转录所必需的。活性人TFIIIC由五个亚基组成。然而，也分离出了一种无活性形式，它缺少五个亚基之一，称为TFIIIC110。有人提出了一个模型，其中pol III转录可能受TFIIIC110的特异性诱导调控，从而使无活性形式形成活性TFIIIC。我们通过用表达TFIIIC110的载体瞬时转染HeLa和HEK293细胞来测试这个模型。我们还构建了稳定转染的HeLa细胞系，其携带用于TFIIIC110的强力霉素诱导型cDNA。我们表明，诱导的TFIIIC110进入细胞核，与其他TFIIIC亚基结合，并在体内被募集到tRNA和5S rRNA基因。然而，对pol III转录本的表达几乎没有影响。这些数据与pol III转录可通过TFIIIC110的特异性诱导有效调节的模型相悖。
Zotero 插件
