Live-cell single RNA imaging reveals bursts of translational frameshifting

Kenneth Lyon; Luis U. Aguilera; Tatsuya Morisaki; Brian Munsky; Timothy J. Stasevich

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/478040 doi: bioRxiv preprint than 40 minutes ( Fig. S13 and Movie S10), representing at least four rounds of translation at our measured elongation rate of ~2.4 aa/sec. Remarkably, this frameshifting translation site associated with another for a large part of the 40-minute imaging window, which supports our hypothesis that the FSS facilitates frameshifting in multi-RNA sites. From the frameshift state survival times, we fit the rate of to be ~0.0013 sec -1 (Fig. 5B S12 ). To account for the different run-off delays seen at frameshifting and non-frameshifting sites (seen in Fig. 4A ,B), the model required elongation pauses of 1/ ~ 48 s at non-frameshifting sites and 1/ * ~ 90 s at frameshifting sites. We explored if codon usage could also explain the differences in run-off times. However, according to the codon adaptation index (Gorgoni et al., 2016; Sharp and Li, 1987) , which is related to the speed at which each codon is translated in the simulation, there is no notable difference between the 0 and -1 frames ( Fig. S14) . Moreover, the distinct pauses predicted by the model are comparable to those previously measured using in vitro and in vivo bulk assays (Lopinski et al., 2000) .