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 (By similarity). As a component of the GATOR2 complex; inhibits GATOR1 complex; an inhibitor of the amino acid-sensing branch of the TORC1 pathway (By similarity). {ECO:0000250}.