Determination and analysis of the complete nucleotide sequence of human herpesvirus

Abstract

Human herpesvirus 7 (HHV-7) is a recently isolated betaherpesvirus that is prevalent in the human population, with primary infection usually occurring in early childhood. HHV-7 is related to human herpesvirus 6 (HHV-6) in terms of both biological and, from limited prior DNA sequence analysis, genetic criteria. However, extensive analysis of the HHV-7 genome has not been reported, and the precise phylogenetic relationship of HHV-7 to the other human betaherpesviruses HHV-6 and human cytomegalovirus has not been determined. Here I report on the determination and analysis of the complete DNA sequence of HHV-7 strain JI. The data establish that the close biological relationship of HHV-6 and HHV-7 is reflected at the genetic level, where there is a very high degree of conservation of genetic content and encoded amino acid sequences. The data also delineate loci of divergence between the HHV-6 and HHV-7 genomes, which occur at the genome termini in the region of the terminal direct-repeat elements and within limited regions of the unique component. Of potential significance with respect to biological and evolutionary divergence of HHV-6 and HHV-7 are notable structural differences in putative transcriptional regulatory genes specified by the direct-repeat and immediate-early region A loci of these viruses and the absence of an equivalent of the HHV-6 adeno-associated virus type 2 rep gene homolog in HHV-7.

Point mutations in the varicella-zoster virus DNA polymerase gene confers resistance to foscarnet and slow growth phenotype

“…Two PFA-resistance [Gibbs et al, 1988;Wong et al, 1988;Hwang et al, 1992]. Below is shown the amino acid sequence of domains II and III from a number of herpesvirus DNA polymerase including : HSV-1, HSV-2, EBV, CMV, HHV-6 [Teo et al, 1991], and HHV-7 [Nicholas, 1996]. Amino acids identical to the VZV sequence are shaded and on consensus (CON), point indicates amino acid relatively conserved in all herpes viruses.…”

Human herpesvirus type 7 in Hodgkin's disease

“…These biological characteristics may be potentially associated with the immunological dysregulations of HD. Additional studies are required for the functional characterization of HHV-7 gene products (Nicholas, 1996), to allow the identification of the presence of specific HHV-7 transcripts and/or proteins with oncogenic potential expressed in HHV-7-latently infected cells, and it will also allow the design of new, more specific viral probes.…”

International Union of Basic and Clinical Pharmacology. LXXXIX. Update on the Extended Family of Chemokine Receptors and Introducing a New Nomenclature for Atypical Chemokine Receptors

“…HHV7 is also widespread and a cause of persistent infection (Wyatt et al, 1991;Latchney et al, 2004). The HHV7 genome encodes two chemokine receptor homologs, U12 and U51 (Nicholas, 1996). Some studies have demonstrated that in K562 cells both receptors elicit calcium flux induced by CCL17, CCL19, CCL21, or CCL22 (Nakano et al, 2003;Tadagaki et al, 2005Tadagaki et al, , 2007, whereas in murine L1.2 cells little response was seen without the coexpression of CCR4 or CCR7 (Tadagaki et al, 2007).…”