|Tatineni, Satyanarayana - Ts|
Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/2008
Publication Date: 6/1/2008
Citation: Tatineni, S., Afunian, M., Hilf, M.E., Gowda, S., Garnsey, S.M., Dawson, W.O. 2008. A capillovirus produces two 3’-terminal and two 5’-terminal sgRNAs in infected tissue: evidence for a CP sgRNA. American Society for Virology 27th annual meeting abstracts. Interpretive Summary:
Technical Abstract: The 6,495 nt positive-stranded RNA genome of Citrus tatter leaf virus-Meyer lemon isolate (CTLV-ML), a Capillovirus, encodes two overlapping open reading frames (ORFs) and has a poly (A) tail at the 3’ end, similar to other capilloviruses. ORF1 (nt 37-6354) encodes a 242-kDa polyprotein containing the domains of replication-associated proteins, and a coat protein (CP) in the C-terminal region. ORF2 (nt 4788-5750) encodes a movement protein (MP), located within ORF1 in a different reading frame. In this study, we examined the production of viral RNAs from CTLV-ML infected tissue, and identified a genome length RNA and two 3’-terminal sgRNAs (3’-sgRNAs) that would contain the MP and CP genes (3’-MP sgRNA), and the CP (3’-CP sgRNA) gene, respectively. Mapping the transcription start site of 3’-MP and 3’-CP sgRNAs revealed that they initiated at a conserved octanucleotide (UUGAAAGA) sequence and are 1,826 and 869 nt with 119 and 15 nt leader sequences, respectively, preceding their putative translation start codons, suggesting that these two 3’-sgRNAs could serve to express MP and CP. Additionally, accumulation of two 5’-terminal sgRNAs (5’-sgRNAs), of 5,586 and 4,625 nt and colinear with the genomic RNA was observed. The 3’ termini of the 5’-sgRNAs mapped to 40 and 44 nt upstream of the transcription start site of 3’-CP and 3’-MP sgRNAs, respectively, possibly produced by termination at the promoter regions of 3’-sgRNAs. We failed to detect the minus strand RNAs corresponding to the 3’- and 5’-sgRNAs in total RNAs extracted from CTLV-ML-infected tissue. Taken together, the presence of a separate 3’-sgRNA corresponding to the CP coding sequence and its cognate 5’-terminal sgRNA would suggest that this capillovirus possesses a dedicated sgRNA for the expression of CP.