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.

As described below, frameshifting is dependent on codon combinations and the physiological state of the cell, and so estimates of frameshifting levels without any productive consequence are only broad generalizations (the initial estimates were extrapolations from the extent of leakiness of frameshift mutants). The consequences of framing infidelity in synthesizing such giant proteins as titin is greater than that for small proteins because of loss due to premature termination by frameshifted ribosomes, but there is currently no evidence for extra long ORF framing fidelity enhancement. In contrast many missense errors are inconsequential. The other extreme is the possibility of ribosomal frameshifting being frequent and ∼100% efficient. The best candidates for this occurs in the decoding of the ciliate Euplotes (30-35).