caa a22 4500 378884107 CHVBK 20180305123438.0 cr unu---uuuuu 161128e20040901xx s 000 0 eng 10.1515/BC.2004.100 doi (NATIONALLICENCE)gruyter-10.1515/BC.2004.100 Tapasin and other chaperones: models of the MHC class I loading complex [Elektronische Daten] [Cynthia Anne Wright, Patrycja Kozik, Martin Zacharias, Sebastian Springer] MHC (major histocompatibility complex) class I molecules bind intracellular virus-derived peptides in the endoplasmic reticulum (ER) and present them at the cell surface to cytotoxic T lymphocytes. Peptide-free class I molecules at the cell surface, however, could lead to aberrant T cell killing. Therefore, cells ensure that class I molecules bind high-affinity ligand peptides in the ER, and restrict the export of empty class I molecules to the Golgi apparatus. For both of these safeguard mechanisms, the MHC class I loading complex (which consists of the peptide transporter TAP, the chaperones tapasin and calreticulin, and the protein disulfide isomerase ERp57) plays a central role. This article reviews the actions of accessory proteins in the biogenesis of class I molecules, specifically the functions of the loading complex in high-affinity peptide binding and localization of class I molecules, and the known connections between these two regulatory mechanisms. It introduces new models for the mode of action of tapasin, the role of the class I loading complex in peptide editing, and the intracellular localization of class I molecules. © Walter de Gruyter Biochemistry nationallicence Molecular biology nationallicence Cellular biology nationallicence calreticulin nationallicence ERp57 nationallicence major histocompatibility complex molecules nationallicence peptide binding nationallicence TAP nationallicence tapasin nationallicence Wright Cynthia Anne Biochemistry and Cell Biology, International University Bremen, D-28759 Bremen, Germany aut Kozik Patrycja Biochemistry and Cell Biology, International University Bremen, D-28759 Bremen, Germany aut Zacharias Martin Bioinformatics and Computational Biology, International University Bremen, D-28759 Bremen, Germany aut Springer Sebastian Biochemistry and Cell Biology, International University Bremen, D-28759 Bremen, Germany aut Biological Chemistry Walter de Gruyter 385/9(2004-09-01), 763-778 1431-6730 385:9<763 2004 385 bchm https://doi.org/10.1515/BC.2004.100 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/BC.2004.100 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wright Cynthia Anne Biochemistry and Cell Biology, International University Bremen, D-28759 Bremen, Germany aut NATIONALLICENCE 700 1- Kozik Patrycja Biochemistry and Cell Biology, International University Bremen, D-28759 Bremen, Germany aut NATIONALLICENCE 700 1- Zacharias Martin Bioinformatics and Computational Biology, International University Bremen, D-28759 Bremen, Germany aut NATIONALLICENCE 700 1- Springer Sebastian Biochemistry and Cell Biology, International University Bremen, D-28759 Bremen, Germany aut NATIONALLICENCE 773 0- Biological Chemistry Walter de Gruyter 385/9(2004-09-01), 763-778 1431-6730 385:9<763 2004 385 bchm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter