FIG. 4.

Western blot analysis of ps20. (a) Left lane (preabsorption), 100 ng rps20 was run on a 12% reducing gel and probed using a 1/1,000 dilution of IG7; right lane (postabsorption), 100 ng rps20 was run on a 12% reducing gel and probed with IG7 after preabsorption with 3 μg rps20 for 2 h at room temperature. (b) Left lane (preabsorption), 10 μl of culture supernatant from 293T transfected with 10 μg of a ps20-encoding expression plasmid per 1 × 10⁵ cells was run on a 12% reducing gel and subsequently probed using a 1/1,000 dilution of anti-ps20 Ab IG7; right lane (postabsorption), 293T transfection supernatant probed with the anti-ps20 Ab preabsorbed with 3 μg rps20 for 2 h at room temperature. (c) Endogenous ps20 expression in 2 × 10⁴ cell equivalents was assessed by immunoblotting with a 1/1,000 dilution of IG7 in cell populations as follows: left lane, ps20 mRNA-negative CD4 T-cell clone; middle lane, ps20⁺ CD4 T-cell clone; right lane, Jurkat cells stably transduced to overexpress ps20.