Distinct 5' UTR Requirements for Translation of the Bicistronic X/P mRNA Among Avian Orthobornaviruses.

ABSTRACT: Orthobornaviruses express X and the phosphoprotein (P) from a bicistronic X/P mRNA, and these proteins regulate polymerase activity. In mammalian orthobornaviruses, the 5' untranslated region (5' UTR) of the X/P mRNA controls the translational balance between X and P and thereby promotes efficient replication. Avian bornaviruses (ABVs) belong to two clades, clade-2 and -3, that differ in the structure and length of the 5' UTR of the X/P mRNA. However, the functional consequences of these differences remain unclear. Using reverse genetics, we generated chimeric viruses by reciprocally exchanging the 5' UTR of the X/P mRNA among clade 2 parrot bornavirus 5 (PaBV-5) and aquatic bird bornavirus 1 (ABBV-1) and clade 3 PaBV-4. In PaBV-5, a long 5' UTR with a stem-loop and an upstream ORF was req

SUBMITTER: Wu MC 

PROVIDER: S-EPMC12868937 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature