title: Impact of beta 2-microglobulin on tapasin expression and covalent association.
abstract: Cellular immunity is dependent on major histocompatibility complex (MHC) class I molecules enabling cytotoxic T cell recognition of malignant and infected cells. Loading of antigenic peptides onto MHC class I is assisted by a peptide-loading protein complex including tapasin. We found that tapasin expression is enhanced by beta 2-microglobulin via both transcriptional and post-transcriptional mechanisms. In addition, using conditions which preserve the tapasin-ERp57 disulfide-bonded conjugate, we demonstrated that beta 2-microglobulin increases tapasin-containing protein complexes, and reduces the level of MHC class I/ERp57 complexes lacking tapasin. Overall, our results provide a new perspective on the regulation of tapasin expression and association.
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Simone
authors.forename: Brittney L
authors.initials: BL
authors.lastname: Smith
authors.forename: Joyce C
authors.initials: JC
authors.lastname: Solheim
mesh_terms: D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004220:Disulfides / Q000378:metabolism; D015870:Gene Expression; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000378:metabolism; D006801:Humans; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D011485:Protein Binding; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001613:beta 2-Microglobulin / Q000235:genetics / Q000378:metabolism*
chemical_list: D004220:Disulfides; D015395:Histocompatibility Antigens Class I; D026901:Membrane Transport Proteins; D001613:beta 2-Microglobulin; C107762:tapasin; C513195:Pdia3 protein, mouse; D019704:Protein Disulfide-Isomerases