title: Structural analysis of class I MHC molecules: the cytoplasmic domain is not required for cytoskeletal association, aggregation and internalization.
abstract: The role of the cytoplasmic domain in a variety of the functional activities of class I MHC molecules has not been documented. To address this question, Jurkat cells were transfected with genes for either native class I MHC molecules or constructs in which all but four cytoplasmic amino acids were deleted. Antibody-induced aggregation and internalization of class I MHC molecules were examined by flow cytometry, and cytoskeletal association was determined by analysing the detergent-resistant fraction of FITC-labeled mAb to class I molecules. The results indicate that the truncated class I MHC molecules are comparable to native class I MHC molecules in the ability to move in the plane of the membrane and aggregate, to associate with the cytoskeleton and to undergo mAb-induced internalization at 37 degrees C. Thus, the cytoplasmic domain of class I MHC molecules is not required for these functional activities.
authors.affiliation: The Harold C. Simmons Arthritis Research Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, USA.
authors.forename: H
authors.initials: H
authors.lastname: Gur
authors.forename: T D
authors.initials: TD
authors.lastname: Geppert
authors.forename: P E
authors.initials: PE
authors.lastname: Lipsky
mesh_terms: D002449:Cell Aggregation; D003593:Cytoplasm / Q000737:chemistry*; D003599:Cytoskeleton / Q000737:chemistry* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004705:Endocytosis; D015789:HLA-A2 Antigen / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000737:chemistry*; D006801:Humans; D019169:Jurkat Cells; D007700:Kinetics; D008970:Molecular Weight; D013329:Structure-Activity Relationship; D014162:Transfection
chemical_list: D015789:HLA-A2 Antigen; D015395:Histocompatibility Antigens Class I