Fig. 2. DGN-1 is glycosylated but not cleaved into /ß subunits. (A) Antibodies to DGN-1 regions corresponding to -DG and ß-DG detect a single major band at 85 kDa (arrow) on western blots of embryo or mixed larval extracts. The anti-DGN-1ß antibody cross-reacts with a bacterial antigen in the larval extract (asterisk). (B) DGN-1 is absent from dgn-1(cg121) lysates probed with anti-DGN-1, demonstrating that cg121 is a molecular null allele. The extract from 25 adult animals was run in each lane. (C) Extracts digested with PNGaseF (protein N-glycosidase F) to remove N-linked glycans (lanes 2,4) were western blotted with anti-DGN-1 antibody. The compact 85 kDa species in embryos shifts to 75 kDa after digestion, near to the predicted polypeptide size. In larval extracts, the broad DGN-1 band decreases in molecular weight after digestion but remains heterogeneous, indicating the presence of N-glycosylation and some additional modification(s), possibly O-glycosylation.