Functional Targeting of DNA Damage to a Nuclear Pore-Associated SUMO-Dependent Ubiquitin Ligase

Recent findings suggest important roles for nuclear organization in gene expression. In contrast, little is known about how nuclear organization contributes to genome stability. Epistasis analysis (E-MAP) using DNA repair factors in yeast indicated a functional relationship between a nuclear pore subcomplex and Slx5/Slx8, a small ubiquitin-like modifier (SUMO)-dependent ubiquitin ligase, which we show physically interact. Real-time imaging and chromatin immunoprecipitation confirmed stable recruitment of damaged DNA to nuclear pores. Relocation required the Nup84 complex and Mec1/Tel1 kinases. Spontaneous gene conversion can be enhanced in a Slx8- and Nup84-dependent manner by tethering donor sites at the nuclear periphery. This suggests that strand breaks are shunted to nuclear pores for a repair pathway controlled by a conserved SUMO-dependent E3 ligase.