BioProject

Embedded in the nuclear envelope, nuclear pore complexes (NPCs) not only regulate nuclear transport, but also interface with both transcriptionally active euchromatin and largely silenced heterochromatin, as well as the boundaries between these regions. More...

Embedded in the nuclear envelope, nuclear pore complexes (NPCs) not only regulate nuclear transport, but also interface with both transcriptionally active euchromatin and largely silenced heterochromatin, as well as the boundaries between these regions. It is unclear what functional role NPCs play in establishing or maintaining these distinct chromatin domains. Here we report that the yeast NPC protein Nup170p interacts with specific regions of the genome containing ribosomal protein and subtelomeric genes. At these locations, Nup170p functions to establish normal nucleosome positioning and as a repressor of transcription. We show that the function of Nup170p in subtelomeric gene silencing is linked to its association with the RSC chromatin-remodeling complex and the silencing factor Sir4p, and that the binding of Nup170p and Sir4p to subtelomeric chromatin is cooperative and necessary for the association of telomeres with the nuclear envelope. Our results establish the NPC as an active participant in the formation of peripheral heterochromatin. Overall design: The genome-wide localization profiles of Nup170p and Nup157p were determined by chromatin immunoprecipitation and DNA microarray analysis using agilent whole genome Saccharomyces cerevisiae arrays. In addition, the localization profile of Nup170p was determined in sir4∆ and yku70∆ strains. Less...