Figure 2
From: An internal ribosome entry site element directs the synthesis of the 80 kDa isoforms of protein 4.1R
The short protein product is synthesized from the ATG2 present in exon 4 and is not a proteolytic fragment from the long protein product. A. Schematic representation of the 4.1R135 mutant cDNAs used in the in vitro assays shown in B. The ATG2 was replaced by GTG in cDNAs 1' and 4' thus generating 1'ATG2mut and 4'ATG2mut, respectively. In the third mutant, a TGA stop codon was introduced between exons 2 and 4 of cDNA 4' (4'STOP). B. Autoradiograph showing the products obtained from the in vitro-coupled transcription and translation reactions of the indicated 4.1R cDNAs. Lanes 1', 4'and 4 correspond to the in vitro products from the wild type cDNAs 1', 4'and 4, respectively.