Figure 5. The CUG Start Is Blocked by a Heat-Stable Hairpin in the 5′ UTR.

COS-7 cells were transfected with cDNA encoding K^b and the indicated constructs. (A and C) The cells were titrated and peptide expression was tested with BCZ103 T cells. (B and D) GFP expression in the transfected cells was assayed by fluorescence-activated cell sorting. GFP fluorescence (shaded histograms) is not observed in untransfected cells (or in cells transfected with a vector not encoding GFP [unpublished data]).