Fig. 4. Tlr and Tld process the pro-peptides of several TGF-ß ligands in Drosophila. (A) Alignment of predicted BMP-1/Tolloid cleavage sites in Act, Daw, Myo and Mav pro-peptides. ^*, residues that were changed to alanine in the mutated forms of the ligands shown in F; red arrow, cleavage site. (B) Schematic of tagged pro-peptide and pro-peptide fragments visible by western analysis. (C-F) Conditioned media from S2^* cells co-transfected with ligands and enzymes as indicated were analyzed by western blotting using anti-V5 antibody for detection of N-tagged pro-peptides and cleaved fragments. Tm designates the corresponding mutant in which the BMP-1/Tolloid site was destroyed.