Role of the adenovirus E3-19k conserved region in binding major histocompatibility complex class I molecules.
The adenovirus early region 3 glycoprotein E3-19k binds to and down regulates major histocompatibility complex (MHC) class I molecules in infected cells. We previously identified a 20-amino-acid conserved region in E3-19k by comparison of protein sequences from four different adenovirus serotypes. The roles of the E3-19k C-terminal and adjacent conserved regions in the interaction with MHC class I molecules have been examined. A functional class I-binding glycoprotein was expressed from the cloned E3 18.5-kDa open reading frame of adenovirus type 35. Truncations and single-amino-acid mutations in the adenovirus type 35 glycoprotein were created by site-directed in vitro mutagenesis and tested for the ability to associate with MHC class I molecules. Deletion of most of the transmembrane domain and cytoplasmic tail did not affect binding to class I molecules. However, removal of an additional 11 amino acids eliminated binding and changed the conformation of the adjacent conserved region. Separate mutations of residues Asp-107 and Met-110, within the conserved region, severely reduced or eliminated binding. These data indicate that the E3-19k conserved region plays a crucial role in binding to MHC class I molecules.
Flomenberg
P
P
Department of Medicine, Medical College of Wisconsin, Milwaukee 53226.
Szmulewicz
J
J
Gutierrez
E
E
Lupatkin
H
H
D000256:Adenoviridae / Q000235:genetics* / Q000276:immunology; D017456:Adenovirus Early Proteins; D000595:Amino Acid Sequence; D000818:Animals; D000957:Antigens, Viral, Tumor / Q000235:genetics; D001483:Base Sequence; D015153:Blotting, Western; D002460:Cell Line; D015395:Histocompatibility Antigens Class I / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D009856:Oncogene Proteins, Viral / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D016366:Open Reading Frames; D015183:Restriction Mapping; D014162:Transfection
D017456:Adenovirus Early Proteins; D000957:Antigens, Viral, Tumor; D015395:Histocompatibility Antigens Class I; D009838:Oligodeoxyribonucleotides; D009856:Oncogene Proteins, Viral