Table 4

Effect of leucine mutations on the expression and membrane targeting of the rLHR

Receptor125I-hCG binding
Intact CellsDetergent ExtractsSurface
ng/106cells % of total
rLHR-wt2.7  ± 0.54.0  ± 1.069  ± 12
rLHR-L613,614,615,616A1.1  ± 0.44.2  ± 1.526  ± 14-150
rLHR-L613,614A3.6  ± 1.75.2  ± 2.064  ± 6
rLHR-L615,616A1.3  ± 0.43.0  ± 0.434  ± 34-150
rLHR-L613A2.0  ± 0.34.9  ± 1.756  ± 4
rLHR-L614A3.8  ± 0.55.2  ± 2.073  ± 6
rLHR-D611N0.6  ± 0.54.5  ± 2.010  ± 44-150

Cells were transiently transfected with the indicated constructs and used to measure cell surface (i.e., binding to intact cells) and total125I-hCG binding (i.e., binding to detergent extracts) as described in Materials and Methods. The percentage of the binding activity present at the cell surface was calculated by dividing the binding detected in intact cells by that detected in detergent extracts.

  • Each value represents the mean ± S.E.M. of three or four independent transfections.

  • 4-150p < .05 compared with rLHR-wt.