FIGURE 9.

Palmitoylation is not essential for gB targeting to the plasma membrane. A, ARPE cells were transfected with the indicated relative amounts of gB- or gB_C777A-coding mRNAs, and gB surface expression was analyzed by flow cytometry as described under “Experimental Procedures.” The data show an mRNA transfection efficiency ≥90%. R. F. U., relative fluorescence units. B, gB surface expression was quantified by CELISA (see “Experimental Procedures”) as in panel A in the presence (light gray) or absence (dark gray) of 50 μm 2Br-palmitate (2Br-p). Error bars indicate mean ± S.D. OD, optical density; A. U., absorbance units. C, transfected ARPE cell extracts were fractionated by the two-phase method (see “Experimental Procedures”), and partition of gB or gB_C777A between total cell membranes (TM), cytoplasmic membranes (CM), and plasma membrane (PM) was analyzed in immunoblots loaded with 10 μg of total proteins and compared with the plasma membrane marker α1 Na⁺/K⁺ ATPase (NKA). D, 60 μg of total proteins of plasma membrane fractions from ARPE cells transfected and processed as in C, with or without prior incubation in 50 μm 2Br-palmitate (2Br-p), were probed in immunoblot for gB or α1 Na⁺/K⁺ ATPase.