Component of the Nup107-160 subcomplex of the nuclear pore complex (NPC). The Nup107-160 subcomplex is required for the assembly of a functional NPC. The Nup107-160 subcomplex is also required for normal kinetochore microtubule attachment; mitotic progression and chromosome segregation. This subunit plays a role in recruitment of the Nup107-160 subcomplex to the kinetochore. As a component of the GATOR2 complex; inhibits GATOR1 complex; an inhibitor of the amino acid-sensing branch of the TORC1 pathway. {ECO:0000269|PubMed:15146057; ECO:0000269|PubMed:17363900; ECO:0000269|PubMed:23723238}.