TY - JOUR
T1 - Transcribing and replicating particles in a double-stranded RNA virus from Leishmania
AU - Weeks, Reitha S.
AU - Patterson, Jean L.
AU - Stuart, Ken
AU - Widmer, Giovanni
PY - 1992/6
Y1 - 1992/6
N2 - During the replicative cycle of many double-stranded RNA viruses, transcription of particles with a double-stranded RNA genome alternates with replication of particles containing a single-stranded genome. In virions infecting some strains of Leishmania guyanensis the putative transcriptase and replicase activities of the RNA-dependent RNA polymerase were previously detected in vitro. Northern hybridization to RNA of known polarity demonstrates that the single-stranded RNA products are of positive polarity and, by definition, are the products of the viral transcriptase. Re-evaluation of previously published data in the light of these findings suggests that transcription in Leishmania viruses is conservative. Sedimentation in sucrose gradients revealed two types of viral particles; single-stranded RNA particles comprised a small fraction of the virus population and sedimented more slowly than the peak of double-stranded RNA particles. In agreement with the replicative model of other dsRNA viruses, these single-stranded particles co-purified with the viral replicase activity that resulted in double-stranded RNA synthesis. In virus-infected promastigote extracts replicase activity decreased with increasing parasite density in culture, suggesting a correlation between cell division and viral replication.
AB - During the replicative cycle of many double-stranded RNA viruses, transcription of particles with a double-stranded RNA genome alternates with replication of particles containing a single-stranded genome. In virions infecting some strains of Leishmania guyanensis the putative transcriptase and replicase activities of the RNA-dependent RNA polymerase were previously detected in vitro. Northern hybridization to RNA of known polarity demonstrates that the single-stranded RNA products are of positive polarity and, by definition, are the products of the viral transcriptase. Re-evaluation of previously published data in the light of these findings suggests that transcription in Leishmania viruses is conservative. Sedimentation in sucrose gradients revealed two types of viral particles; single-stranded RNA particles comprised a small fraction of the virus population and sedimented more slowly than the peak of double-stranded RNA particles. In agreement with the replicative model of other dsRNA viruses, these single-stranded particles co-purified with the viral replicase activity that resulted in double-stranded RNA synthesis. In virus-infected promastigote extracts replicase activity decreased with increasing parasite density in culture, suggesting a correlation between cell division and viral replication.
KW - Double-stranded RNA virus
KW - Leishmania
KW - RNA-dependent RNA polymerase
KW - Replicase
KW - Transcriptase
UR - http://www.scopus.com/inward/record.url?scp=0026608283&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026608283&partnerID=8YFLogxK
U2 - 10.1016/0166-6851(92)90053-M
DO - 10.1016/0166-6851(92)90053-M
M3 - Article
C2 - 1620160
AN - SCOPUS:0026608283
VL - 52
SP - 207
EP - 213
JO - Molecular and Biochemical Parasitology
JF - Molecular and Biochemical Parasitology
SN - 0166-6851
IS - 2
ER -