The role of the upstream AUGs in Triticum mosaic virus 5’ leader sequence

Triticum mosaic virus (TriMV, Poacevirus titrici) is an unconventional potyvirus with a long 5UTR (739 nt) containing 13 upstream AUGs (uAUGs). Similar to animal picornavirus, TriMV employs an internal ribosome entry site (IRES) in its 5'UTR for cap-independent translation.Generated TriMV mutants: uORF10 peptide HA-tag AUG 10 to AUC AUGUAA (Premature stop codon) Conclusions Two strong ribosomal footprints were identified at uAUG5 (bp 281) and uAUG10 (bp 525) by Ribo-seq. This suggests active translation of 2 putative peptides. Several modular elements of the TriMV, including YX-AUG and polypyrimidine tracks have been described. Mechanism to initiate translation still unknown, as well as the potential role of uAUGs in viral IRES-driven translation or viral life cycle.