Effects of C3 exotransferase or pertussis toxin on enhanced binding of 70-kD N-terminal fragment of fibronectin to MG63 cells by LPA, nocodazole, or S1P. Confluent MG63 cells were pretreated with complete medium (None), 50 mg/L C3 transferase (C3), or 100 μg/L pertussis toxin (PTX) for 24 hours and then incubated for 60 minutes with ¹²⁵I-70-kD fragment in medium with 200 nmol/L LPA (▩), 10 μmol/L nocodazole (), or 100 nmol/L S1P (▪). Data are presented as specific binding in the presence of additive divided by specific binding in the absence of any additives as a percentage of control. Data represent the mean ± SD (n = 4).