Figure 3.
Identification of TM8-Sec61α photoadducts. CFTR mRNAs either lacking a UAG codon (−UAG) (lanes 1–10) or with a UAG at codon 913 (lanes 11–20) were truncated at indicated residues and expressed in the presence of NYT peptide and ε-ANB-lys-tRNACUA. Equal amounts of read-through polypeptides, determined by phosphorimaging, were immunoprecipitated with Sec61α antisera and analyzed by SDS-PAGE as described in Materials and Methods. Bands migrating between 14 and 30 kDa represent nonspecific adsorption of nascent polypeptides to protein A beads.