FIGURE 7.

HRD1 Ub ligase mediates TCRα ubiquitination. A and B, HeLa cells were transfected with the indicated constructs. Ubiquitination of TCRα-HA was determined in the absence of MG132 as described in the legend to Fig. 1B with the exception of using anti-FLAG antibody instead of anti-Myc polyclonal antibody to detect ubiquitinated TCRα-HA. C, ubiquitinated TCRα-HA levels were normalized to non-ubiquitinated TCRα-HA levels. Values represent the mean ± S.E. from three independent experiments. *, p < 0.05 versus untreated with HRD1 cDNA (Control).