Generation of C-terminus-free RON and RON160 and their expression in NIH3T3 cells: (A) Schematic representation of the RON, RON160 and their C-terminus-free variants. RON is composed of a 40 kDa α-chain and a 150 kDa β-chain. The β-chain has several domains including a sema domain, a PSI motif, four IPT units, followed by a transmembrane (TM) domain, a juxtamembrane domain, a tyrosine kinase (TK) domain, and a short C-terminal tail. The generation of C-terminus-free RON or RON160 variants was carried out as detailed in Materials and Methods. (B) Cells (1 × 105 cells/sample) were incubated for 45 min at 4°C with mAb Zt/g4 (1 μg/sample) or normal mouse IgG (1 μg/sample) followed by goat anti-mouse IgG coupled with FITC. Immunofluorescent intensities were measured by FACSan. One of two experiments with similar results.