Ribosomal frameshifting and transcriptional slippage: From genetic steganography and cryptography to adventitious use

Atkins, John F.; Loughran, Gary; Bhatt, Pramod R.; Firth, Andrew E.; Baranov, Pavel V.

The codons directly 5 of human antizyme 1 ORF1 stop specify NLGPGPRWCS (where S is encoded by the shift codon UCC, see Table 2 just above). This is similar to the sequence, NPGPVQS, directly 5 of the tandem −1 frameshift shift site utilized in expression of Theiler's murine encephalomyelitis and Saffold cardioviruses (58, 59) . The first part of this sequence can be written NPG/P to signify that the G is the C-terminal amino acid of the upstream-encoded protein that is liberated by the action of StopGo. The P is the N-terminal amino acid of the protein whose synthesis involves frameshifting. [One of the names for the phenomenon of nascent peptide mediated release, without a stop codon, of upstream encoded protein and continued translation (without initiation) to specify a downstream encoded protein (479) is StopGo (480) .] Whether the nascent peptide context required for StopGo serves to exclude eEF5 prior to facilitating hydrolysis of the ester linkage required for liberation of the upstream encoded protein is unknown. Under the conditions tested, which do not include altered polyamine levels, StopGo has not been shown to influence the frameshifting (58, 59) . However, whether naturally there is some influence of polyamine levels remains to be determined.