Leader sequence distinguishes between translatable and encapsidated measles virus RNAs.
The 3'-terminal 55 nucleotides of the negative-strand measles virus RNA genome called the leader sequence is not transcribed into a detectable distinct RNA product. Most of the monocistronic N and bicistronic N-P RNAs lack the leader sequence. However, a subpopulation of the N and N-P RNAs and all of the antigenomes possess this leader. Here, we show that leader-containing subgenomic RNAs are functionally distinct from their leaderless counterparts. In measles virus-infected cells, leaderless monocistronic N and bicistronic N-P RNAs were associated with polysomes. By contrast, leader-containing N and N-P RNAs were found exclusively in nonpolysomal ribonucleoprotein complexes that were resistant to RNase and had a buoyant density of 1.30 g/ml, the same as that of antigenomic ribonucleoprotein complexes. Both antigenomic and subgenomic ribonucleoprotein complexes were specifically immunoprecipitated by antiserum against the N protein, and leaderless RNAs were not found in these complexes. These findings suggest that measles virus distinguishes RNAs destined for encapsidation or translation by the presence or absence of a leader sequence.
Department of Microbiology, University of Washington School of Medicine, Seattle 98195.
S J
SJ
Castaneda
T C
TC
Wong
D000818:Animals; D001483:Base Sequence; D002213:Capsid / Q000235:genetics*; D002460:Cell Line; D005796:Genes; D005814:Genes, Viral; D008459:Measles virus / Q000235:genetics*; D008969:Molecular Sequence Data; D009522:Newcastle disease virus / Q000235:genetics; D010222:Parainfluenza Virus 1, Human / Q000235:genetics; D012313:RNA / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics* / Q000302:isolation & purification; D012261:Ribonucleoproteins / Q000302:isolation & purification; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014721:Vesicular stomatitis Indiana virus / Q000235:genetics; D014758:Viral Core Proteins / Q000235:genetics*
D012333:RNA, Messenger; D012367:RNA, Viral; D012261:Ribonucleoproteins; D014758:Viral Core Proteins; D012313:RNA