Figure 6.
Cell surface half-life (A) and endocytosis (B) of the chimeric receptor αYβ18-27 in cells preincubated with or without (control) proteasome inhibitor (lactacystin), chloroquine, or the lysosomal proteases inhibitor leupeptin. Cells were incubated with 25 μM lactacystin, 200 μM chloroquine, or 100 μM leupeptin for 3 h at 37°C and experiments performed as described in Figure 1. Cell surface expression of the chimera on cells treated for different times with 50 μM cycloheximide was assayed by flow cytometry (A) with mAb 2A3A1H. The kinetics of endocytosis was measured and results expressed as internalization rate constants (B). The results presented in A and B are the means ± SE of at least three independent experiments.