title: Physical association of the K3 protein of gamma-2 herpesvirus 68 with major histocompatibility complex class I molecules with impaired peptide and beta(2)-microglobulin assembly.
abstract: To persist in the presence of an active immune system, viruses encode proteins that decrease expression of major histocompatibility complex class I molecules by using a variety of mechanisms. For example, murine gamma-2 herpesvirus 68 expresses the K3 protein, which causes the rapid turnover of nascent class I molecules. In this report we show that certain mouse class I alleles are more susceptible than others to K3-mediated down regulation. Prior to their rapid degradation, class I molecules in K3-expressing cells exhibit impaired assembly with beta(2)-microglobulin. Furthermore, K3 is detected predominantly in association with class I molecules lacking assembly with high-affinity peptides, including class I molecules associated with the peptide loading complex TAP/tapasin/calreticulin. The detection of K3 with class I assembly intermediates raises the possibility that molecular chaperones involved in class I assembly are involved in K3-mediated class I regulation.
authors.affiliation: Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: Y Y Lawrence
authors.initials: YY
authors.lastname: Yu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Harris
authors.forename: Lonnie
authors.initials: L
authors.lastname: Lybarger
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Kimpler
authors.forename: Nancy B
authors.initials: NB
authors.lastname: Myers
authors.forename: Herbert W
authors.initials: HW
authors.lastname: Virgin
authors.forename: Ted H
authors.initials: TH
authors.lastname: Hansen
mesh_terms: D000818:Animals; D015536:Down-Regulation; D018142:Gammaherpesvirinae / Q000472:pathogenicity / Q000502:physiology*; D006566:Herpesviridae Infections / Q000821:virology; D015395:Histocompatibility Antigens Class I / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D007739:L Cells; D051379:Mice; D010455:Peptides / Q000378:metabolism*; D017510:Protein Folding; D014764:Viral Proteins / Q000502:physiology*; D001613:beta 2-Microglobulin / Q000378:metabolism*
chemical_list: D015395:Histocompatibility Antigens Class I; D010455:Peptides; D014764:Viral Proteins; D001613:beta 2-Microglobulin