Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9289400 | Virus Research | 2005 | 13 Pages |
Abstract
We have identified and characterized a cyclin homolog from Bombyx mori nucleopolyhedrovirus (BmNPV), encoding a 34Â kDa protein (ORF 120) with 48% homology to the host Bombyx mori cellular cyclin B. The expression of the viral cyclin (v-cyc) was detected from 12Â h following virus infection and the maximum transcript levels were seen at 24-36Â h. The transcription start site mapping of v-cyc revealed the presence of a transcript initiating from a TAAG motif located 13 nucleotide (nt) upstream of the ORF as well as longer transcripts initiating from farther upstream region and encompassing the preceding ORF 119. The transcription was terminated at 15Â nt downstream of the ORF 120. The expression of the host cellular cyclin B declined following virus infection and the transcript disappeared almost completely by 24Â h even as the expression of v-cyc reached high levels. The synthesis of the viral cyclin was detected at 36-48Â h post-infection. The viral cyclin in association with other host or viral proteins catalysed phosphorylation of histone H1. The host cells were arrested in G2/M phase following virus infection and thus, the virus cyclin in association with other proteins maintains the host cells at the G2/M phase while permitting the virus DNA replication.
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Authors
Sudhakar Baluchamy, Karumathil P. Gopinathan,