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.
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.
Yu
Y Y Lawrence
YY
Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Harris
Michael R
MR
Lybarger
Lonnie
L
Kimpler
Lisa A
LA
Myers
Nancy B
NB
Virgin
Herbert W
HW
Hansen
Ted H
TH
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*
D015395:Histocompatibility Antigens Class I; D010455:Peptides; D014764:Viral Proteins; D001613:beta 2-Microglobulin