| First Author | Custódio N | Year | 2006 |
| Journal | Exp Cell Res | Volume | 312 |
| Issue | 13 | Pages | 2557-67 |
| PubMed ID | 16765347 | Mgi Jnum | J:111331 |
| Mgi Id | MGI:3653778 | Doi | 10.1016/j.yexcr.2006.04.018 |
| Citation | Custodio N, et al. (2006) Abundance of the largest subunit of RNA polymerase II in the nucleus is regulated by nucleo-cytoplasmic shuttling. Exp Cell Res 312(13):2557-67 |
| abstractText | Eukaryotic RNA polymerase II is a complex enzyme composed of 12 distinct subunits that is present in cells in low abundance. Transcription of mRNA by RNA polymerase II involves a phosphorylation/dephosphorylation cycle of the carboxyl-terminal domain (CTD) of the enzyme's largest subunit. We have generated stable murine cell lines expressing an alpha-amanitin-resistant form of the largest subunit of RNA polymerase II (RNA Pol II LS). These cells maintained transcriptional activity in the presence of alpha-amanitin, indicating that the exogenous protein was functional. We observed that over-expressed RNA Pol II LS was predominantly hypophosphorylated, soluble and accumulated in the cytoplasm in a CRM1-dependent manner. Our results further showed that the transcriptionally active form of RNA Pol II LS containing phosphoserine in position 2 of the CTD repeats was restricted to the nucleus and its levels remained remarkably constant. We propose that nucleo-cytoplasmic shuttling of RNA Pol II LS may provide a mechanism to control the pool of RNA polymerase subunits that is accessible for assembly of a functional enzyme in the nucleus. |
