CD147 regulates tyrosine phosphorylation induced via CD98 or CD29 ligation.

(A) U937 cells were incubated in the presence of CD98-AHN-18 (1.5 μg/mL), MEM 101A (CD29, 0.5 μg/mL), MEM M6/1 (CD147, 2.5 μg/mL), BU89 (CD98, 2.3 μg/mL), or combinations of these antibodies for 20 minutes. Cells were lysed and analyzed for phosphotyrosine proteins as described in “Materials and methods.” Molecular weights of the major phosphorylated species are shown on the left and were calculated by image analysis of the Western blot, with the use of molecular weight standards to calibrate the software. Lane 1, isotype control; lane 2, MEM M6/1 (CD147); lane 3, CD98-AHN-18; lane 4, MEM 101A (CD29); lane 5, CD98-AHN-18 + CD147; lane 6, MEM 101A (CD29) + CD147; lane 7, BU89 (CD98); lane 8, CD98-AHN-18 + BU89 (CD98). (B) The relative intensities of the major phosphotyrosine species in bands 3, 5, and 8, calculated by means of gel image analysis software.