Baculovirus gene ME53, which contains a putative zinc finger motif, is one of the major early-transcribed genes

Abstract

We have been investigating the first viral genes to be transcribed in Spodoptera frugiperda cells after the infection with Autographa california nuclear polyhedrosis virus in order to identify regulatory proteins required for the activation of early and/or late gene transcription. By screening a cDNA library from polyadenylated RNA transcribed at 1 h postinfection, we identified a gene which is designated ME53. This newly identified gene is located upstream of the late p74 gene and forms a divergent promoter unit with the immediate-early gene IE0. The determination of the nucleotide sequence of ME53 has revealed an open reading frame encoding a gene product of 53 kDa. Furthermore, the sequence data suggest a putative DNA binding motif, a zinc finger, whose functional significance has yet to be shown. Transcription of ME53 does not require previous viral protein synthesis, and during infection, the level of promoter activity seems to be independent of trans-acting viral factors, as suggested by transient expression studies.