Elements regulating Potato leafroll virus sgRNA1 translation are  located within  the coding sequences of  the coat protein and  read-through domain.
Translation of viral proteins from subgenomic RNAs (sgRNAs) is a common strategy among positive-stranded RNA viruses. Unlike host mRNA, sgRNA of Potato leafroll virus (PLRV) does not possess a cap at its 5' end nor a poly(A) tail at the 3' terminus, both of which are known to be crucial for translation of RNA in eukaryotic cells. Here, we demonstrate, that in wheat germ extract (WGE) truncation of the sgRNA1 5' UTR increases translation efficiency, as it has previously been observed in rabbit reticulocyte lysate (RRL), whereas removal of the 3' UTR does not affect translation. We also describe two regulatory elements located within the coding sequence of the coat protein (CP) gene and its read-through domain (RTD) and are responsible for regulation of in vitro translation of the PLRV sgRNA1. The frst element is composed of the purine sequence AAAGGAAA located between the AUG codons of the CP and 17K genes. Deletion of this domain or its substitution by pyrimidines reduced by half the translation of both genes, whereas deletion of the RTD resulted in a 3.6-fold reduction in translation efficiency. This is the first report of translation regulatory elements of plant viruses located within a coding region.
Department of Protein Biosynthesis, Institute of Biochemistry and Biophysics PAS, Warszawa, Poland. alfap@ibb.waw.pl
Adrianna
A
Łoniewska-Lwowska
Sylwia
S
Chełstowska
Włodzimierz
W
Zagórski-Ostoja
Andrzej
A
Pałucha
D020121:5' Untranslated Regions / Q000235:genetics; D003062:Codon; D015967:Gene Expression Regulation, Viral; D016679:Genome, Viral; D052679:Luteoviridae / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis / Q000502:physiology; D012367:RNA, Viral / Q000235:genetics*; D014764:Viral Proteins / Q000378:metabolism
D020121:5' Untranslated Regions; D003062:Codon; D012367:RNA, Viral; D014764:Viral Proteins