FIG. 2.

Detection of p56^lck expression by Western blot analysis. HeLa CD4⁺/p56^lck, HeLa CD4⁺, HeLa p56^lck, HeLa CD4⁺ Cyt⁻, HeLa CD4 (C420S)/p56^lck, HeLa CD4 (S408A)/p56^lck, and HeLa CH4 extracts containing 50 μg of total cellular proteins were electrophoresed in an SDS–10% polyacrylamide gel and blotted to a PVDF membrane. The membrane was incubated with a mixture of anti-p56^lck and antiactin MAbs and then reacted with GAM Ig-peroxidase conjugate. Bound MAbs were revealed by incubation of the membrane with ECL reagent and exposure to Hyperfilm-ECL. Controls consist of lysates from MT2 cells (a human T-cell leukemia virus type 1-transformed CD4⁺ T-cell line which lacks p56^lck expression) and CEM cells (a CD4⁺ T-cell line which expresses p56^lck).