Fig. 2. Chondroitin sulfate affects targeting of NG2 to retraction fibers. B28 cells expressing wild-type NG2 (clone 6, a,b,g,h), NG2/S1342A (clone 42, c,d), NG2/S999A (clone 51, e,f), NG2/L1 (clone 5, i,j) and NG2/CNTN (clone M, k,l) were grown on poly L-lysine-coated dishes overnight. In panels g and h, cells expressing the wild-type NG2 were chondroitinase treated for 1 hour at 37°C. All sets of cells were then colchicine treated (10^-5 M) for 30 minutes at 37°C and stained with monoclonal anti-NG2 antibody (b,d,f,h,j,l) and poly-specific rabbit anti-B28 antibody (a,c,e,g,i,k). After colchicine treatment, all cells exhibit dense arrays of retraction fibers as shown by the staining with poly-specific antibody. However, NG2 staining in the NG2/S999A cells is much weaker than in the wild-type or NG2/S1342A cells. Removal of chondroitin sulfate from cells expressing wild-type NG2 also results in diminished localization of NG2 to the retraction fibers (g,h). Diminished, punctate NG2 staining in retraction fibers is also seen in the NG2/CNTN transfectants, whereas no retraction fiber staining for NG2 is observed for NG2/L1. Bar, 10 µm (j).