Vaccinia virus late transcription is activated in vitro by cellular heterogeneous nuclear ribonucleoproteins.
Vaccinia virus gene expression is temporally regulated, and three gene classes have been identified: early, intermediate, and late. Several virus-encoded proteins and an activity designated VLTF-X are required for maximum transcription in vitro of a template containing a late promoter. VLTF-X is present in both cytoplasmic and nuclear extracts prepared from uninfected mammalian cells and co-purifies with a late promoter DNA-binding activity. Here, extensive purification of VLTF-X has revealed that heterogeneous nuclear ribonucleoproteins A2/B1 and RBM3 co-purified with in vitro late transcription stimulation. Overexpression and purification of these proteins from Escherichia coli demonstrated that they both complemented for VLTF-X activity in in vitro transcription reactions. These studies identify two host cell factors potentially contributing to poxvirus replication in vivo.
Wright
C F
CF
Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, USA. wrightcf@musc.edu
Oswald
B W
BW
Dellis
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D015153:Blotting, Western; D002848:Chromatography, DEAE-Cellulose; D017931:DNA Primers; D006367:HeLa Cells; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D012261:Ribonucleoproteins / Q000502:physiology*; D014157:Transcription Factors / Q000302:isolation & purification / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*; D014616:Vaccinia virus / Q000235:genetics*
D017931:DNA Primers; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; C439768:hnRNP A2