Recruitment of an Activated Gene to the Yeast Nuclear Pore Complex Requires Sumoylation.

In addition to their role in regulating transport across the nuclear envelope, increasing evidence suggests nuclear pore complexes (NPCs) function in regulating gene expression. For example, the induction of certain genes (e.g., yeast ) is accompanied by their movement from the nuclear interior to NPCs. As sumoylation has been linked to the regulation of chromatin spatial organization and transcriptional activity, we investigated the role of sumoylation in the expression and NPC recruitment of the gene. We observed that induction of is accompanied by both increased and decreased sumoylation of proteins associated with specific regions along the locus. Furthermore, we show that the E3 ligase Siz2/Nfi1 is required for targeting the locus to the NPC where it interacts with the SUMO isopeptidase Ulp1. Our data suggest that this interaction is required for both the association of with the NPC and for its normal expression. These results imply that sumoylation is a key regulator of targeting to the NPC, and a cycle of sumoylation and NPC-associated desumoylation events contribute to the regulation of expression.