BICP22 of bovine herpesvirus 1 is encoded by a spliced 1.7 kb RNA which exhibits immediate early and late transcription kinetics

• Published in: Journal of general virology 1994-07, Vol.75 (7), p.1703-1711
• Main Authors: Schwyzer, Martin, Wirth, Urs V, Vogt, Bernd, Fraefel, Cornel
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Base Composition; Base Sequence; Biological and medical sciences; DNA, Viral - analysis; Exons; Fundamental and applied biological sciences. Psychology; Genes, Immediate-Early - genetics; Genes, Viral - genetics; Genetics; Herpesvirus 1, Bovine - genetics; Immediate-Early Proteins - chemistry; Immediate-Early Proteins - genetics; Kinetics; Microbiology; Molecular Sequence Data; Phosphoproteins - chemistry; Phosphoproteins - genetics; Promoter Regions, Genetic - genetics; Repressor Proteins; Restriction Mapping; RNA Splicing; RNA, Viral - genetics; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Transcription, Genetic - genetics; Viral Proteins; Virology
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-75-7-1703

Institute of Virology, Faculty of Veterinary Medicine, University of Zürich, Winterthurerstrasse 266a, CH-8057 Zürich, Switzerland Kinetic analysis of the two divergent immediate early (IE) transcription units of bovine herpesvirus 1 (BHV-1) revealed an unexpected behaviour. The IE1.7 promoter was not turned off at the end of the IE period but acted as a late promoter, unlike the adjacent IE4.2/2.9 promoter which was active only under IE conditions. The genome region specifying the IE1.7 gene was sequenced (0.814 to 0.839 map units). The IE1.7 promoter was found to overlap with duplicated sequence elements bearing close similarity to herpesvirus origins of replication, which may explain the biphasic transcription kinetics. Exons 1 and 2 of the spliced IE1.7 transcript were non-coding. Exon 3 was found to contain a single open reading frame encoding a protein of 300 amino acids that was designated BICP22 because of its homology to ICP22 (Vmw68) of herpes simplex virus type 1 and related proteins from other herpesviruses. The protein probably represents IEP-55, the most abundant BHV-1 phosphoprotein observed under IE conditions. Present address: Sonnsyterain 8, CH-6048 Horw, Switzerland. Received 5 November 1993; accepted 26 January 1994.