Functions as a component of the nuclear pore complex (NPC) and the COPII coat. At the endoplasmic reticulum; SEC13 is involved in the biogenesis of COPII-coated vesicles. 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:23723238; ECO:0000269|PubMed:8972206}.