Identifying the RNA Polymerases that Synthesize Specific Transcripts of the Autographa Californica Nuclear Polyhedrosis Virus

Abstract

Nuclear run-on assays carried out in the presence and absence of the RNA polymerase II inhibitor, ~t-amanitin, were used to determine the exact timing of the switch from inhibitor-sensitive transcription catalysed by host RNA polymerase II, to inhibitor-resistant transcription catalysed by the baculovirus-induced RNA polymerase. These studies revealed that the onset of ~-amanitin-resistant transcription is just after 6 h post-infection, simultaneous with the beginning of the late phase of infection. They also showed that transcripts from the p26 gene in the HindIII Q/P region and the p35 gene in the HindlII K/Q region of the viral genome are synthesized by the host RNA polymerase II both early and late in infection. On the other hand, transcripts of the p 10 gene in the HindII! Q/P region and the y transcripts in the HindIII K region are synthesized by the ~-amanitin-resistant, virus-induced RNA polymerase late in infection.

Molecular biology of baculovirus and its use in biological control in Brazil

“…Os promotores da classe E se assemelham a promotores eucarióticos e utilizam a RNA polimerase II do hospedeiro, uma vez que são sensíveis a alfaamanitina (Huh & Weaver, 1990). A seqüência de nucleotídeos TATA, localizada numa posição anterior ao ponto de início de transcrição, é conservada em muitos promotores E (Blissard & Rohrmann, 1990) e essencial para a transcrição nessa fase (Guarino & Summers, 1988;Blissard & Rohrmann, 1991;Dickson & Friesen, 1991).…”

“…Esta fase é dependente da expressão de genes da classe E e da replicação do DNA viral (Friesen & Miller, 1986;Huh & Weaver, 1990;Lu & Carstens, 1991). Os genes desta classe são, geralmente, relacionados à montagem e oclusão das partículas virais (OReilly et al, 1992).…”

“…Uma característica marcante da expressão de genes da classe L é a resistência à alfa-amanitina, um inibidor de RNA polimerase II (Huh & Weaver, 1990). Essa resistência indica a presença de uma RNA polimerase modificada, seja pela adição de uma subunidade codificada pelo vírus, ou mesmo uma nova RNA polimerase viral.…”

Tissue specificity of a baculovirus-expressed, basement membrane-degrading protease in larvae of Heliothis virescens

“…Immediate early and early genes are transcribed before the onset of viral DNA replication. Genes in this phase of the virus lifecycle are transcribed by the host RNA polymerase II (Huh and Weaver, 1990). Late and very late genes are transcribed by a virally encoded RNA polymerase (Guarino et al, 1998).…”

Untitled

“…The transcripts are synthesized by the host RNA polymerase II throughout the infection cycle [22], accumulating in the cytoplasm. The peptide is normally present in the membrane fraction of budded virus [23] and has been shown to be non-essential for in vitro replication [24].…”