Nucleotide sequence and molecular analysis of the rhesus cytomegalovirus immediate-early gene and the UL121-117 open reading frames

Abstract

Cytomegalovirus (CMV) has been isolated from many nonhuman primates, including rhesus macaques (Macaca mulatta). To better understand the molecular biology of rhesus CMV (RhCMV), a 9.2-kb DNA restriction fragment spanning the immediate-early (IE) gene has been molecularly cloned and sequenced. Open reading frames (ORF) have been identified and transcripts mapped for regions corresponding to exons 1, 2, 3, and 4 of the IE1 protein of human CMV (HCMV) and to exons 1, 2, 3, and 5 of IE2. The predicted RhCMV IE1 protein was 29 and 40% identical with the HCMV and African green monkey (AGM) CMV IE1 proteins, respectively, and the predicted RhCMV IE2 protein was 48 and 65% identical with the HCMV and AGM CMV IE2 proteins, respectively. Five additional ORF 3' to the RhCMV IE gene were identified which contained significant homologies with the HCMV UL121-UL117 ORF. The predicted translation products ranged from 29 to 47% identical with, and 52 to 66% similarity to the corresponding ORF of HCMV. Conservation of nucleic and amino acid sequences, and colinearity of genes, between primate CMV genomes contribute to a better understanding of primate CMV evolution, regulation, and pathogenesis.