Host cell proteins bind specifically to the capsid-cleaved 5' end of Leishmaniavirus RNA.
Leishmaniavirus (LRV) is a double-stranded RNA (dsRNA) virus that persistently infects some strains of the protozoan parasite, Leishmania. LRV generates a short transcript, corresponding to the 5' end of the positive-sense RNA (320 nt), via a cleavage event mediated by the viral capsid protein on the full-length positive sense RNA transcript. To address the possibility that the RNA cleavage represents a regulatory mechanism for maintaining persistent infection, the interactions between Leishmania cytoplasmic proteins and in vitro synthesized viral transcripts were studied. In gel mobility shift experiments, three specific RNA/protein complexes were formed between cellular proteins and the cleaved viral transcript, and three major proteins were labeled by UV cross-linking. No protein binding activity was observed for either the short (320 nt) or full-length RNA transcripts. However, the two cleavage reaction products were able to form stable RNA/RNA complexes. We present a model in which the virus is targeting its own transcript for cleavage to promote binding of host factors to cryptic domains inaccessible in the full-length transcript.
Saiz
M
M
Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Ro
Y T
YT
Wirth
D F
DF
Patterson
J L
JL
D020121:5' Untranslated Regions; D001665:Binding Sites; D002213:Capsid; D002460:Cell Line; D019199:Leishmaniavirus / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*
D020121:5' Untranslated Regions; D012333:RNA, Messenger; D012367:RNA, Viral; D016601:RNA-Binding Proteins