Western blotting analysis of cell lyzates of HEK293T/17 cells transiently transfected with expression vectors harboring genes for mCD3zeta wild type and six different mCD3zeta mutants, where particular ITAM tyrosines were substituted with phenylalanines. The lysates (non-reducing conditions) were immunoblotted with mouse Monoclonal antibody anti-pY111 mCD3zeta (clone EM-55) (Product # MA5-28539). 1: Wt mCD3zeta pervanadate non-stimulated; 2: Wt mCD3zeta pervanadate stimulated; 3: mut. mCD3zeta Y/F2-6; 4: mut. mCD3zeta Y/F1 and 3-6; 5: mut. mCD3zeta Y/F1-2 and 4-6 (thus only pY111 remains native); 6: mut. mCD3zeta Y/F1-3 and 5-6; 7: mut. mCD3zeta Y/F1-4 and 6; 8: mut. mCD3zeta Y/F1-5.