Molecular analysis of the trans-activating IE-2 gene of Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus

Virology. 1992 Mar;187(1):84-96. doi: 10.1016/0042-6822(92)90297-3.

Abstract

A second immediate early (IE) regulatory gene of the baculovirus Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus (OpMNPV) has been identified. The IE-2 gene which is homologous to the IE-N gene of Autographa californica MNPV was mapped to the HindIII A fragment of OpMNPV between 0.41 to 1.37 map units. The IE-2 gene codes for a predicted protein of 45,640 Da and analysis of the amino acid sequence shows that the protein has a highly basic amino terminal domain and a cysteine-rich domain that is similar to a zinc finger motif that is also found in the baculovirus proteins GC30 and PE-38. The IE-2 gene is expressed as a 1.3-kb transcript that was detectable by 0.5 hr postinfection (hr p.i.), reached maximum steady state levels by 6 hr p.i., and declined slightly by 48 hr p.i. Cis-acting 5' regulatory sequences were analyzed by deletion analysis of the IE-2 promoter linked to the reporter gene chloramphenicol acetyl transferase. Maximum expression was obtained when the IE-2 promoter contained sequence 275 bp upstream from the transcriptional start site. trans-Activation analysis revealed that IE-2 trans-activated the IE-1 promoter and in addition appeared to be autoregulatory.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Baculoviridae / genetics*
  • Base Sequence
  • Blotting, Northern
  • Blotting, Southern
  • Cell Line
  • Cloning, Molecular
  • Genes, Regulator*
  • Immediate-Early Proteins*
  • Molecular Sequence Data
  • Plasmids / genetics
  • Promoter Regions, Genetic / genetics
  • Sequence Alignment
  • Sequence Homology, Nucleic Acid
  • Trans-Activators / genetics*
  • Transcriptional Activation
  • Viral Proteins / genetics*

Substances

  • Immediate-Early Proteins
  • Trans-Activators
  • Viral Proteins
  • IE2 protein, polyhedrosis virus