Construction and Characterization of a Human Cytomegalovirus Mutant With the UL18 (Class I Homolog) Gene Deleted

J Virol. 1992 Nov;66(11):6784-7.


The UL18 open reading frame of human cytomegalovirus (HCMV) (which encodes a product homologous to major histocompatibility complex class I heavy chains) has been disrupted by insertion of the beta-galactosidase gene under control of the major HCMV early promoter. The recombinant virus delta UL18 showed no phenotypic differences from wild-type HCMV in terms of single-step growth curves or particle/infectivity ratios, indicating that the UL18 gene product is dispensable for the growth of HCMV in human fibroblasts in vitro. The synthesis of the mature cellular class I heterodimer is shut down in cells infected at a high multiplicity with wild-type HCMV, and a similar effect was seen in delta UL18-infected fibroblasts, suggesting that although the UL18 gene product can associate with beta 2 microglobulin, it is not directly involved in the disruption of class I assembly.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cells, Cultured
  • Cytomegalovirus / genetics*
  • Cytomegalovirus / growth & development
  • Fibroblasts
  • Genes, MHC Class I
  • Genes, Viral / genetics*
  • Humans
  • Lac Operon / genetics
  • Major Histocompatibility Complex / physiology
  • Molecular Sequence Data
  • Mutagenesis, Insertional
  • Phenotype
  • Promoter Regions, Genetic / genetics
  • Viral Proteins / genetics*
  • Virus Replication / genetics


  • Viral Proteins