Structure of human cytoplasmic Pol II complex explains global transcription repression by Gdown1
Schmitzova, J.; Zhan, Y.; Rengachari, S.; Grabbe, F.; Dybkov, O.; Urlaub, H.; Lidschreiber, M.; Dienemann, C.; Cramer, P.
Show abstract
RNA polymerase II (Pol II) is a 12-subunit enzyme crucial for gene transcription in the nucleus. However, its assembly in the cytoplasm, nuclear import, and nuclear function of assembly factors remain poorly understood. Here, we isolated Pol II from the cytoplasmic fraction of human cells (cfPol II) and determined its cryo-EM structure. The structure reveals that Pol II is fully assembled in the cytoplasm before nuclear import. We also found that Gdown1 binds Pol II through three distinct regions, indicating it may stabilize Pol II assembly intermediates. Notably, Gdown1 binding precludes the association of essential transcription factors IIB and IIF, rendering cfPol II inactive in promoter-dependent transcription in vitro. Our results provide a basis for Gdown1-dependent global transcription repression and suggest a model for the role of Gdown1 in Pol II assembly, import, and transcription regulation.
Matching journals
The top 2 journals account for 50% of the predicted probability mass.
Similar papers in this journal
- Structural basis of Ty3 retrotransposon integration at RNA Polymerase III-transcribed genes 98%
- Melbournevirus encodes a shorter H2B-H2A doublet histone variant that forms structurally distinct nucleosome structures. 98%
- Helical reconstruction of VP39 reveals principles for baculovirus nucleocapsid assembly 98%
Similar papers in this journal
"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.