Pseudouridine-mediated stop codon read-through in S. cerevisiae is sequence context-independent.

Pseudouridine-mediated stop codon read-through in S. cerevisiae is sequence context-independent.
RNA. 2020 May 20;:
Authors: Adachi H, Yu YT
Abstract
We have previously shown that when the uridine of a stop codon (UAA, UAG or UGA) is pseudouridylated, the ribosome reads through the modified stop codon. However, it is not clear as to whether or not the pseudouridine (Ψ)-mediated read-through is dependent on the sequence context of mRNA. Here, we use several different approaches and the yeast system to address this question. We show that when a stop codon (pre-mature termination codon, PTC) is introduced into the coding region of a reporter mRNA at several different positions (with different sequence contexts) and pseudouridylated, we detect similar levels of read-through. Using mutational and selection/screen analyses, we also show that the upstream sequence (relative to PTC) as well as the nucleotides surrounding the PTC (upstream and downstream) play a minimal role (if at all) in Ψ-mediated ribosome read-through. Interestingly, we detect no suppression of NMD (nonsense-mediated mRNA decay) by targeted PTC pseudouridylation in the yeast system. Our results indicate that Ψ-mediated nonsense suppression occurs at the translational level, and that the suppression is sequence context-independent, unlike some previously characterized rare stop codon read-through events.
PMID: 32434780 [PubMed - as supplied by publisher]

Source: RNA - May 19, 2020 Category: Genetics & Stem Cells Authors: Adachi H, Yu YT Tags: RNA Source Type: research