Identification and Characterization of a Putative Baculoviral Transcriptional Factor IE-1 from Choristoneura fumiferana Granulovirus

Abstract

A gene that encodes a protein homologue to baculoviral IE-1 was identified and sequenced in the genome of the Choristoneura fumiferana granulovirus (ChfuGV). The gene has an 1278 nucleotide (nt) open-reading frame (ORF) that encodes 426 amino acids with an estimated molecular weight of 50.33 kDa. At the nucleotide level, several cis-acting regulatory elements were detected within the promoter region of the ie-1 gene of ChfuGV along with other studied granuloviruses (GVs). Two putative CCAAT elements were detected within the noncoding leader region of this gene; one was located on the opposite strand at -92 and the other at -420 nt from the putative start triplet. Two baculoviral late promoter motifs (TAAG) were also detected within the promoter region of the ie-1 gene of ChfuGV. A single polyadenylation signal, AATAAA, was located 18nt downstream of the putative translational stop codon of ie-1 from ChfuGV. At the protein level, the amino acid sequence data that was derived from the nucleotide sequence in ChfuGV IE-1 was compared to those of the Cydia pomonella granulovirus (CpGV), Xestia c-nigrum granulovirus (XcGV) and Plutella xylostella granulovirus (PxGV). The C-terminal regions of the granuloviral IE-1 sequences appeared to be more conserved when compared to the N-terminal regions. A domain, similar to the basic helix-loop-helix like (bHLH-like) domain in NPVs, was detected at the C-terminal region of IE-1 from ChfuGV (residues 387 to 414). A phylogenetic tree for baculoviral IE-1 was constructed using a maximum parsimony analysis. A phylogenetic estimation demonstrates that ChfuGV IE-1 is most closely related to that of CpGV.

Identification, Characterization and Phylogenic Analysis of Conserved Genes within the odvp-6e/odv-e56 Gene Region of Choristoneura fumiferana Granulovirus

“…At the nucleotide level, one TATA element, two putative CCAAT elements, a (A/C/T)CA(G/T)T motif (proposed consensus for arthropod transcriptional initiator elements), and two baculoviral late promoter motifs (TAAG) were detected within the 5' NTR of this gene. A domain, which is similar to the basic helix-loop-helix like (bHLH-like) domain in NPVs, was detected at the C-terminal region of IE-1 from ChfuGV (Rashidan et al, 2002a). The phylogenetic estimation demonstrated an obvious separation between GVs and NPVs, and showed that ChfuGV IE-1 is most closely related to that of CpGV and PhopGV.…”

Sequencing and Characterisation of p74 Gene in Two Isolates of Anticarsia Gemmatalis MNPV

“…and/or promoter enhancement [27][28][29]. Within the putative p74 promoter region there is a typical very late INR (TAAG) 13 bp upstream the ATG codon [30][31][32][33][34]. All group I NPVs have an identical motif in the promoter region.…”

Desarrollo de un sistema de recombinación para su aplicación al estudio de determinantes genéticos que afectan la infectividad de baculovirus de interés agronómico

“…tanto en NPV como en GV, la información acerca de estos genes en GV es escasa en la literatura (Rashidan et al, 2002). Este trabajo, es un aporte que analiza el gen ie-1…”

“…Estudios previos de comparación entre las proteínas IE-1 de cuatro GV y diez NPV, muestran que los valores de similitud entre las mismas no superan el 15%(Rashidan et al, 2002). Los resultados de la comparación de a pares entre las distintas secuencias de proteínas de IE-1 de GV se presentan en la Tabla 111.5.…”

“…Así, se identificó a IE-1 de NPV como el transactivador viral más importante, que participa en las distintas etapas del ciclo viral. Si bien, se encontraron homólogos a IE-1 en los genomas de Granulovirus secuenciados hasta el momento, el análisis particular de este gen sólo se ha restringido a nivel de secuencia(Rashidan et al, 2002). Una de las principales razones de esto, es la falta de líneas celulares permisivas a la infección por GV, mientras que este obstáculo no existe en el caso de…”