Overexpression of CD81 decreases the levels of TfR2.
A, overexpression of CD81 decreases the levels of TfR2 but not TfR1. Hep3B-TfR2 cells were transfected with pcDNA3 empty vector (EV) or pcDNA3-CD81-Myc (CD81) for 48 h. Blots of cell lysates were probed with anti-TfR2, anti-TfR1, and anti-actin antibodies. The levels of TfR2 and TfR1 were normalized to that of actin. The change of TfR2 and TfR1 relative levels and CD81 in response to overexpression of CD81 was normalized to the mock-transfected cells. The graph shows the average results of 16 independent experiments. B, overexpression of CD81 decreases the levels of TfR2CD/TfR1-f. Hep3B-TfR2CD/TfR1-f cells were transfected with empty vector pcDNA3 (empty vector) or pcDNA3-CD81-Myc (CD81) for 48 h. The immunoblot was probed with rabbit-anti-Flag, anti-actin, and H68.4, an antibody to the cytoplasmic domain of TfR1. The changes of TfR2CD/TfR1-f and TfR1 levels were analyzed as described in A. The graphs show the average data from nine experiments. C, overexpression of CD81-Myc decreases the levels of TfR2ΔCD. Hep3B-TfR2ΔCD cells were transfected with control pcDNA3 or pcDNA3-CD81-Myc (CD81) for 48 h. The levels of TfR2ΔCD and TfR1 were immunodetected and analyzed as described in A. The graph in C shows the average data from three experiments.