Nucleoporin 153 links nuclear pore complex to chromatin architecture by mediating CTCF and cohesin binding [RNA-Seq]

Establishment of cell lineage specification, maintenance of cellular states and cellular responses to developmental cues rely on gene regulation and spatial genome organization during early development. Emerging data point to highly coordinated activity between epigenetic mechanisms that involve nuclear architecture, chromatin structure and chromatin organization. We show that the nuclear pore complex (NPC) basket protein, Nucleoporin 153 (NUP153) interacts with the nuclear architectural proteins, CTCF and cohesin, and mediates their binding across cis-regulatory elements in pluripotent mouse embryonic stem (ES) cells. NUP153 depletion results in altered occupancy of architectural proteins coupled with differential changes in transcription. This affect is most prevalent at the bivalent genes. To provide molecular insights onto NUP153-mediated gene regulation, we utilized Epidermal Growth Factor (EGF)-inducible immediate early gene (IEG) loci, which we identified as NUP153 targets. IEG transcription is regulated through a POL II pause-release mechanism. We provide evidence that NUP153 is critical for CTCF and cohesin occupancy and subsequent POL II recruitment to the IEG proximal-promoter sites during the paused state. In particular, establishment of a poised IEG chromatin environment relies on co-regulatory function of NUP153 and CTCF, which underlies efficient and timely IEG transcription at the NPC. Our results uncover a key role for the mammalian NPC in distribution of chromatin architectural proteins and demonstrate that NUP153 acts as a cis-acting factor that causally links the NPC to chromatin organization during transcription regulation.