FIG. 10.
The cysteine residues in the extracellular domain of Sf-RON are required for gp55 interaction and Epoind BFU-E colony formation. (A) 293 cells were transfected with wild-type gp55 and myc-tagged wild-type or mutated Sf-RON. Cell lysates were immunoprecipitated with anti-myc antibody and blotted with anti-gp55 antiserum. (B) 293 cells were transfected with gp55 and myc-tagged wild-type or mutated Sf-RON. Cell lysates were blotted with anti-phospho-RON tyrosine 1238/1239 antibody. The membrane was stripped and then blotted with anti-myc antibody. (C) 293 cells were transfected with wild-type or mutated MSCV-myc-Sf-RON and pEco. At 48 h posttransfection, viral supernatants were collected and incubated overnight with bone marrow cells of C57BL/6 mice. The infected bone marrow cells were plated in methylcellulose medium containing IL-3 (2.5 ng/ml) or incubated with FVP on ice for 1 h prior to plating in methylcellulose medium containing IL-3 (2.5 ng/ml). On day 5, BFU-E colonies were stained with acid-benzidine and counted. *, P < 0.01. Error bars indicate standard deviations.