UAS regulatory sequences drive expression of full-length nac coding sequence (from the RE40567 cDNA clone), mutated to carry the R125C amino acid replacement; this mutation is equivalent to the R147C mutation in Hsap\SLC35C1 that is associated with congenital disorder of glycosylation IIc (CDG IIc). The coding sequence is tagged at the C-terminal end with Tag:HA.