The GPN proteins are a conserved family of GTP-binding proteins that are involved in the assembly and subsequent import of RNA polymerase II and III. In this study, we sought to ascertain the specificity of yeast GPN2 for RNA polymerases by screening the localization of a collection of 1350 GFP-tagged nuclear proteins in WT or GPN2 mutant cells. We found that the strongest mislocalization occurred for RNA polymerase II and III subunits and only a handful of other RNAPII associated proteins were altered in GPN2 mutant cells. Our screen identified Ess1, an Rpb1 C-terminal domain (CTD) prolyl isomerase, as mislocalized in GPN2 mutants. Building on this observation we tested for effects of mutations in other factors which regulate Rpb1-CTD phosphorylation status. This uncovered significant changes in nuclear-cytoplasmic distribution of Rpb1-GFP in strains with disrupted RNA polymerase CTD kinases or phosphatases. Overall, this screen shows the exquisite specificity of GPN2 for RNA polymerase transport, and reveals a previously unappreciated role for CTD modification in RNAPII nuclear localization.
Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details.
| Gene | Phenotype | Experiment Type | Mutant Information | Strain Background | Chemical | Details |
|---|---|---|---|---|---|---|
| GPN2 | heat sensitivity: increased | classical genetics | conditional Allele: gpn2-1 E97D, I153T, K176E, K181R, E331G | S288C | Temperature: elevated temperature, 34 °C | |
| GPN2 | protein/peptide distribution: abnormal Reporter: Cwc22-GFP | classical genetics | conditional Allele: gpn2-2 C19S | S288C | Temperature: semi-permissive temperature, 30 °C Details: decrease in the nuclear nuclear localization of Cwc22p | |
| GPN2 | protein/peptide distribution: abnormal Reporter: Ess1-GFP | classical genetics | conditional Allele: gpn2-2 C19S | S288C | Temperature: semi-permissive temperature, 30 °C Details: decrease in the nuclear nuclear localization of Ess1p | |
| GPN2 | protein/peptide distribution: abnormal Reporter: Fkh2-GFP | classical genetics | conditional Allele: gpn2-2 C19S | S288C | Temperature: semi-permissive temperature, 30 °C Details: decrease in the nuclear nuclear localization of Fkh2p | |
| GPN2 | protein/peptide distribution: abnormal Reporter: Fob1-GFP | classical genetics | conditional Allele: gpn2-2 C19S | S288C | Temperature: semi-permissive temperature, 30 °C Details: decreased nuclear signal intensity of Fob1p | |
| GPN2 | protein/peptide distribution: abnormal Reporter: Lif1-GFP | classical genetics | conditional Allele: gpn2-2 C19S | S288C | Temperature: semi-permissive temperature, 30 °C Details: decrease in the nuclear nuclear localization of Lif1p | |
| GPN2 | protein/peptide distribution: abnormal Reporter: Mlp2-GFP | classical genetics | conditional Allele: gpn2-2 C19S | S288C | Temperature: semi-permissive temperature, 30 °C Details: reduced signal intensity and altered localization of Mlp2p, a nuclear envelope-associated protein | |
| GPN2 | protein/peptide distribution: abnormal Reporter: Rpa12-GFP | classical genetics | conditional Allele: gpn2-2 C19S | S288C | Temperature: semi-permissive temperature, 30 °C Details: increase in the nuclear:cytoplasmic ratio and mean nuclear GFP intensity of multiple RNAPI subunits including: Rpa12p, Rpa34p, and Rpa190p | |
| RPO21 | protein/peptide distribution: abnormal Reporter: Rpa190-GFP | classical genetics | conditional Allele: rpo21-1 | S288C | Temperature: permissive temperature, 25 °C Details: increase in the nuclear:cytoplasmic ratio and mean nuclear GFP intensity of Rpa190p, an RNAPI subunit at permissive temperature and a further increase at elevated temperature | |
| RTR2 | protein/peptide distribution: abnormal Reporter: Rpb1-GFP | classical genetics | null Allele: rtr2-Δ | S288C | Details: increase in the nuclear:cytoplasmic ratio of Rpb1p, suggestive of a negative regulatory role in RNAPII import through phosphorylation of the CTD |
Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.
| Evidence ID | Analyze ID | Interactor | Interactor Systematic Name | Interactor | Interactor Systematic Name | Allele | Assay | Annotation | Action | Phenotype | SGA score | P-value | Source | Reference | Note |
|---|
Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.
| Interactor | Interactor | Assay | Annotation | Action | Modification | |
|---|---|---|---|---|---|---|
| CWC22 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification | |
| ESS1 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification | |
| FKH2 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification | |
| FOB1 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification | |
| LIF1 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification | |
| MLP2 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification | |
| RPB11 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification | |
| RPB3 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification | |
| RPB7 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification | |
| RPO21 | GPN2 | Co-localization | manually curated | Bait-Hit | No Modification |