Pulse-chase analysis of PRLR levels in transfected CHO-K1 cells. (A) CHO-K1 cells were transfected either with pPRLR-MPFlag or hPRLR-Flag, pulsed with Tran35S-Label, and chased for 24 h. These gels are representative of three independent experiments. (B) The combined doublet of pPRLR-MP bands (74 and 77 kDa) and the single hPRLR band (84 kDa) were quantified using NIH Image. Results are presented as means ± S.E.M. (n = 3). The rate of decay of the pPRLR-MP did not differ from that of the hPRLR (P > 0.8).