2025-03-20 ノースウェスタン大学
<関連情報>
- https://news.northwestern.edu/stories/2025/03/new-function-discovered-protein-in-leukemia/
- https://www.cell.com/molecular-cell/fulltext/S1097-2765(25)00144-3
核膜孔複合体における転写因子を介したクロマチンのドッキングに、Exportin-1はアダプターとして機能する Exportin-1 functions as an adaptor for transcription factor-mediated docking of chromatin at the nuclear pore complex
Tiffany Ge∙ Donna Garvey Brickner∙ Kara Zehr∙ … ∙ Brian Chait∙ Michael P. Rout∙ Jason H. Brickner
Molecular Cell Published:March 10, 2025
DOI:https://doi.org/10.1016/j.molcel.2025.02.013
Graphical abstract
Highlights
- Crm1 co-occupies hundreds of enhancers and promoters with nuclear pore proteins
- Crm1 functions upstream of Nups to mediate peripheral targeting of genes
- Crm1 and Nup2 promote nascent transcription of hundreds of genes
- Crm1 binding to the Gcn4 TF and Nup2 is mechanistically distinct from NES binding
Summary
Nuclear pore proteins (nucleoporins [Nups]) physically interact with hundreds of chromosomal sites, impacting transcription. In yeast, transcription factors mediate interactions between Nups and enhancers and promoters. To define the molecular basis of this mechanism, we exploited a separation-of-function mutation in the Gcn4 transcription factor that blocks its interaction with the nuclear pore complex (NPC). This mutation reduces the interaction of Gcn4 with the highly conserved nuclear export factor Crm1/Xpo1. Crm1 and Nups co-occupy enhancers, and Crm1 inhibition blocks interaction of the nuclear pore protein Nup2 with the genome. In vivo, Crm1 interacts stably with the NPC and in vitro, Crm1 binds directly to both Gcn4 and Nup2. Importantly, the interaction between Crm1 and Gcn4 requires neither Ran-guanosine triphosphate (GTP) nor the nuclear export sequence binding site. Finally, Crm1 and Ran-GTP stimulate DNA binding by Gcn4, suggesting that allosteric coupling between Crm1-Ran-GTP binding and DNA binding facilitates the docking of transcription-factor-bound enhancers at the NPC.
