Ligation of CD98 or CD29 induces rapid and distinct patterns of tyrosine phosphorylation.

U937 cells were incubated in the presence of CD98-AHN-18 (1.5 μg/mL) (A) or MEM 101A (CD29, 0.5 μg/mL) (B) for various time periods. 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.