FIG. 5.

(A) [³⁵S]methionine-labeled RXRα and TR isoforms, with controls containing unprogrammed lysate incubated with T3 or T7 polymerase (RRL). β3 products were derived from full-length cDNA and constructs lacking exon A (TRβ3ExB) or the 5′-UTR (TRβ3ORF); Δβ3 products were derived from full-length cDNA and constructs lacking exon A (TRΔβ3CP) or the 5′-UTR (TRΔβ3TR). The 32.5-kDa Δβ3 product consists of two proteins, resolved after further electrophoresis. (B) Products from wild-type TRβ1, TRβ3, and TRΔβ3 cDNAs and constructs in which the AUG codon at position 174 in β1, 103 in β3, and 1 in Δβ3 was mutated to CTG (TRβ1mut, TRβ3ORFmut, and TRΔβ3TRmut).